Should Niacinamide and L-Ascorbic Acid Be Used Together?

Personal/Inspirational, Skin Care

These days, while it’s (more) common knowledge that acidic compounds like hydroxy acids should not be used with retinol, the interaction between niacinamide and L-ascorbic acid  –two very prominent and well-studied compounds  – is rarely discussed. Ironically, along with hydroxy acids and retinoids, these two compounds to a great extent constitute and represent four of the five main classes of ingredients that should be included in everyone’s ideal skin care routine; the fifth class being sunscreen, of course!

[Read more: Spotlight on Vitamin B3 (Niacinamide or Nicotinic Acid]

I’m surprised that this interaction hasn’t gotten more press! Therefore, let’s dive right in.

What Exactly Is This interaction?

pH Matters Skin

L-ascorbic acid ( a form of vitamin C) requires a pH of less than 3.5 in order to penetrate the skin, which is very close to the 3.8 pH value where maximum complexation occurs between itself and niacinamide. L-ascorbic acid is the naturally-occurring form of vitamin C, while niacinamide is the –amide form of niacin or vitamin B3 as discussed in a previous post. When mixed together in aqueous solutions (since both are water-soluble vitamins), they form a 1:1 complex that turns the solution yellow, rendering both compounds useless. This complexation may be the result of a donor-acceptor interaction between L-ascorbic acid (donor) and niacinamide (acceptor), which may be similar to the interaction that occurs between tryptophan and niacinamide.

Furthermore, in the presence of UV light and oxygen, which seems likely since antioxidants (such L-ascorbic acid and niacinamide) are frequently and complementarily used with sunscreens to enhance UV protection (and since oxygen is everywhere), the two compounds may even generate the very reactive hydrogen peroxide compound through a 4-step chain reaction.  

Now, the amount of complexation is pH dependent, with the maximum value occurring at a pH of 3.8. Since L-ascorbic acid requires a pH of 3.5 or lower in order to be protonated and absorbed into the skin, the likelihood of this interaction occurring and its consequent impacts are significant.

[Read more: Should Niacinamide and Acidic Ingredients Be Used Together?]

So, to make a long story short: don’t mix the two compounds!

Does This Occur with Vitamin C Derivatives?

Hydrogen Peroxide is a Free Radical

In the presence of UV light, niacinamide and L-ascorbic acid can form hydrogen peroxide, a known pro-oxidative compound. Most, if not all, vitamin C derivatives such as ascorbyl tetraisopalmitate, magnesium ascorbyl phosphate, and ascorbyl glucoside, have to convert to L-ascorbic acid in order to have vitamin effects on the skin. This conversion process takes place after the derivates have penetrated into the skin. (Wouldn’t it be nice if they converted in the bottle?!) And because this conversion takes place within the skin, the pH of the surrounding solution or environment is no longer very low. However, the pH of skin is still acidic.

[Read more: Why You Should Use Niacinamide Only with Reserveratrol]

Therefore, interactions between any converted L-ascorbic acid and niacinamide are still possible. Keep in mind that the rates of conversion and penetration of the various derivatives can vary drastically, meaning that some may be more prone to complexation than others.

Fortunately, the pro-oxidative tendencies of hydrogen peroxide can be ignored in this scenario, since its formation is not possible in the absence of UV light.

So What Should I Do?     


I think the more appropriate question is, “What should I NOT do?”

Clearly, it is my recommendation to NOT use niacinamide and L-ascorbic acid together since even in the absence of UV light, it would have an overall negative effect compared to when the two compounds are used separately. In the presence of UV light, the two compounds can form the pro-oxidative ROS-generator hydrogen peroxide, in addition to the 1:1 complex discussed above.

And while this interaction with niacinamide was only documented with L-ascorbic acid, it seems logical to suggest that it may also occur (albeit to much lesser extent) with vitamin C derivatives since they convert to L-ascorbic acid after penetrating into the skin. However, the amount of the 1:1 complex forming in these cases involving vitamin C derivatives is likely irrelevant. 

Now, if you feel compelled and that you MUST use these two compounds together, try to use them at nighttime and/or wait 30 minutes between application to allow for the pH of the skin to return to its (more) natural state.

[Read more: Which is Better: Niacinamide or Peptides?]

I hope this was a fun post and feel free to ask any questions down below or on my blog! And if you’ve been using both of these compounds together, don’t be afraid to share your (old) routine!  

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  • Nathalie Mancilla

    Hi, I just discover FutureDerm and I love it. What do you think about use a product that already combine niacinamide with sodium ascorbyl phosphate (Mad Hippie eye cream). Its well enough to use it at night (vs morning) to avoid the hydrogen peroxide generation? or its preferable to look for separate products and different times to apply them in order to have the maximum benefit of both ingredients? What should you do in your own skin care routine? Thank you!!!!!!!!

  • Ella Darling

    Geez, you are wrong on so many levels, I’m now refusing to read your posts anymore. It’s well accepted that niacinamide can combine with any ingredient for the skin and only enhance it. Your post about Retinol being rendered useless by adding acids (like hydroxy or ascorbic acid) is wrong too. Heck, Roc, the leading manufacturer of Retinol, puts ascorbic acid in their day moisturizer. I could go on and on, but what’s the use. I am done, and rely on my dermatologist and clinical studies to get accurate info. Shame on you.

    • I am sorry you feel that way, however, I stand by what I said.

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  • bumblejeaniepie

    Ok, so what if I have a sunblock or moisurizer that contains LAA or MAP or THA or whatever form of C, but in small amounts and in a formula that gives me little reason to believe it is active anymore.. should I still avoid using it in conjunction with a niacinamide serum? And should I be using a product that uses such a formula in the first place?

  • Shirley


    I just found your site and it is so informative! I was looking at trying the SkinMedica Lytera Skin Brightening Complex that I saw at my dermatologist’s office. Paula gave me 5 stars. But then I came across your article and have second thoughts. The product has Niacinamide and Tetrahexyldecyl Ascorbate. Does this mean that I should avoid this?

    This is the full ingredient list:
    Water/Aqua/Eau, Niacinamide, Butylene Glycol, Tetrahexyldecyl Ascorbate, Polyacrylate-13, Caprylic/Capric Triglyceride, Tetrapeptide-30, Hexylresorcinol, 4-Ethoxybenzaldehyde, Retinol, Glycyrrhiza Glabra (Licorice) Root Extract, Ethyl Linoleate, Dunaliella Salina Extract, Tocopherol, Squalane, Cetyl Ethylhexanoate, Glycerin, Polyisobutene, Polysorbate 20, Phytic Acid, Disodium EDTA, Ethylhexylglycerin, Potassium Sorbate, Phenoxyethanol.

    Thanks so much for your help.

  • John

    Thank you so much for this very didactic (scientific) post! I was planning on using/buying Timeless vitamin C serum (a brand that you should really review because they have excellent products!) as part of my PM skin care routine and use Cerave’s PM moisturizer which contains NIACINAMIDE among other beneficial ingredients. 🙁 both are really good products and I was hoping to solicit an advice from you! Furthermore I am also planning on introducing a Ubiquinone serum from the same brand, but don’t know if it’ll negatively affect my skin due to the interactions of both Vitamin C and Niacinamide! I am a teenager and my skin is acne-prone and really oily. I am partly of Asian descent and aside from acne (which I have really good control over) my next-to-the-top skincare problem are hyperpigmentations! I just really, desperately want to get my skin in the right direction of improvement! Knowing that most, if not all, skin lighteners are strong antioxidants really assuages me of my worries of not having beneficial ingredients on my skin! The second question I want to ask is, what are the best skin lighteners out there that have ample and eclectic research under their belt and how can I optimally use ALL of them (maybe you should do a post about this) ? I heard that Ubiquinone is a very good skin-lightener, but very susceptible to degradation when exposed to the elements. If that’s the case will pouring in its contents in a pump-style bottle (granted that air has briefly touched it during the packaging replacement) increase its longevity? What about placing it in the refrigerator?

    I apologize for the long winded inquiry, I don’t know where else to turn to… and I really appreciate this website! Very informative and user friendly!

  • Bojana

    Would you please take a look at this product and write what you think, would it be safe to use it since it is product with SPF 50??
    Thank you very much in advance!

    Aqua (Water), Dicaprylyl Carbonate, Uriage Thermal Spring Water, Methylene Bis, Benzotriazolyl Tetramethylbutylphenol, Butyl Methoxydibenzoylmethane, Ethylhexil Triazone, Niacinamide, Nylon I2, Triacontanyl PVP, Decyl Glucoside, Ascorbyl Tetraisopalmitate, Butylene Glycol, C20/22 Alkyl Phosphate, C20/22 Alcohols, Phenoxyethanol, Xanthan Gum, Benzoic Acid, Tetrasodium Edta, Tocopheryl Acetate, O Cymen 5 Ol, Propylene Glycol, Glycyrrhiza Glabra (Licorice) Root Extract, Citric Acid, Sodium Hydroxide.

  • MH


    Should I be using Futurederm Moisturiser with Futurederm Vitamin CE Caffeic serum as the moisturiser contains Niacinamide?

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  • Katia A

    Hi! I’m a total skin nerd and have very much enjoyed your blog. However, after doing an endless amount of research, I can’t figure out the best anti aging routine. I want to use: a low pH cleanser, an anti-oxident serum, sunblock, vitamin b3, retinol, and aha/bhas.

    I can’t seem to figure out how to use all of the listed products without creating negative reactions! I have not been able to figure out how to incorporate aha/bhas and vitamin b3 with the other listed ingredients. My current routine is:
    – cerave cleanser
    – antioxident serum (SkinCeuticals CE Ferulic or Rationale SUPER ANTIOXIDANT ACE Rejuvenating Serum)
    – alta MD sunblock

    – cerave cleanser
    – (sometimes add a prescriotion acne gel, then wait 20 min)
    – tretinonin .05%

    The Rationale skin care line has an “essential 6” product line which basically covers the main buckets I listed above, but they say to use their vitamin b3 serum (Rationale IMMUNOLOGIST Niacinamide Serum) right before the vitamin C containing anti oxidant. Is this harmful? And if you are using retinol at night, how do you layer properly? can you use it with vitamin b3? Help!!!!! I want to figure out how to use all of the listed products in the most effective way.

    Thank you so much, I’ve looked everywhere and haven’t been able to get this question answered.

  • Grace Young

    I adore your site! Reading this, I’m wondering if nicotinic acid + ascorbic acid would have the same pro-oxidant effect. (The reason is because I use Nia24 and Kinerase together, but I just realized today that ascorbic acid was in the latter’s ingredient list.) Is the chain reaction only because the -amide form of niacin reacts with the acidic portion of L-AA? If so, would it be okay to use the acidic form with vitamin C? Thanks so much!

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  • Nicki Zevola

    Hi @Emma — Yes, I think you should be fine. Though certain antioxidants like Phloretin CF or L-ascorbic acid stay in the skin for up to 72 full hours, the vast majority of it is in the skin for 8-24 hours, and then there is a “trickle-down” effect. That’s why I always reapply antioxidant serums daily, even though there are still trace amounts in my skin from day(s) before.

    Hope this helps!

    • Emma

      Thank you, Nicki :-)! With that being said, since majority is in the skin for 8-24 hours, and you recommend applying antioxidant serums daily, would you say to just avoid the niacinamide altogether? I had used an olay regenerist serum as well in the past, which has vitamin B3 (I think) and I read you saying there is a possibility they interact because of its similarity structurally to niacinamide so I haven’t used it…I liked the moisture and benefits it provided…but it doesn’t seem like it’s possible to have it all with vitamin C and niacinamide (and B3). I think the best question is what do you do for your skincare regimen?

  • emma

    phloretin cf stays in the skin for up to 72 hours. can i use niacinamide the next day even though vitamin c will still be there?

  • Shraddha

    Hello John,

    I’m so glad that I stumbled on this site while researching niacinamide. However, my question is a bit different and doesn’t include niacinamide. What I wanted to know was that in a vitamin C serum (especially when it is DIY), how does one ensure that the accompanying ingredients in the serum are not compromising the ph level of the ascorbic acid in the serum?

    To be more specific, I make a DIY serum of ascorbic acid, rose water, aloe vera, hyaluronic acid, jojoba and witch hazel. In this serum, the first three ingredients are active ingredients and the rest three are minimal. Do you think that the ph level of ascorbic acid in this mixture will be compromised given the ph levels of the other ingredients? I have seen some positive results using this serum so I know that it works, but I wanted to be sure that I’m using it at its best potency. If not, could you suggest an optimal mix for the serum? I have dry-combination skin, which sometimes turns oily-combination.

    Secondly, is it okay to use ascorbic acid mixed with a moisturizer? This follows from my concern stated previously.

    Thirdly, assuming that there’s nothing wrong with this serum and its potency, how long should you wait before applying a sunscreen (I use a moisturizing one–specifically, the Missha Safe Sun Essence SPF 45).


    • bumblejeaniepie

      Get ph strips and test! That’s a very important part in making a safe and effective C serum! Most bloggers leave that essential step out.

      I think it’s fine to apply a moisturizer or sunscreen as soon as your serum is absorbed, although this article certainly makes a good case for not doing so if your moisturizer has any niacinamide in it.

  • Rasha

    I am so glad I came across this post. I have been struggling with a recent breakout (29 year old female) after having a few years with pretty great skin. My derm put me on 2 prescriptions 2 weeks ago and I am working my own products in where they fit. I cleanse in the morning with First Aid Beauty regular cleanser, tone with Lush tea tree water and I am using Elta MD UV Clear BUT mix a spoonful of my Philosophy Turbo C Powder. I was using a different SPF prior to my Derm visit. I like the Elta but now I am scared Im causing more damage adding my Vit C powder to it now. Where can I work in the Vit C? I notice it really helps my skin. If it helps, here is my night routine- Same cleanser, tone with First Aid Beauty Radiance Pads (low % of AHA), alternate Aczone an Differin Gel .3% on nights and then a moisturizer from my Derm. I also have a 10% AHA from that I would love to work in at night but I am guessing not on Differin nights. Should I also not be toning with my AHA pads when I use Differin? I really appreciate your help and response!

  • lala

    I want to add the list of ingredients of secret key milky pack : Titanium dioxide, sodium hyaluronic acid, niacinamide, sorbitan rate, Ceresin, methylparaben, purified water, spices, cyclopentasiloxane cyclohexanone siloxane, dimethicone, cyclopentasiloxane, butylene glycol, not chilpi / p Fiji -10 /dimethicone cross 1 dimethicone, penta-cycle Annals Sandi the Chicon vinyl menu polymer, di- methyl siloxane

  • lala

    hello, I want to make my own sunscreen by mixing jergens ultra healing body lotion with micronised zinc oxide, is that ok?

    second choice : secret key milky pack (contains niacinamide) with micronised zinc oxide , which one is safer & more effective?

  • Nicki Zevola

    Hi @Jennifer,

    Yes, we do not recommend using any moisturizer (including ours!) with niacinamide in conjunction with vitamin C.

    Instead, I recommend this moisturizer with our Vitamin CE Caffeic Silk Serum 16+2:

    Hope this helps,

  • Jennifer

    Is it safe to use your Moisturizer Number 25 with your Vitamin C serum? Isn’t that contrary to what this article instructs?

  • Hi Angela,

    I answered almost the exact same question many times in this post. The most recent time (I think 🙂 was to the reader “Sam.” Please scroll up and read his question and my response. It’s on the same page of comments as this one.

    Let me know if you have any other questions!

  • Angela

    Hi John,

    This is a little confusing as another post on FutureDerm suggests using Vitamin C then NIA 24? Can you please explain as I use Timeliess Vitamin C in the morning followed by a leave on glycolic cream and tretinoin at night but really want to incorporate Niacinamide as well. SHould I use this after the tretinoin at night? Your advice would be greatly appreciated

  • @dee

    To make an incredibly long story short, it’s pretty much okay to use the two ingredients together–that is a conditional statement of course. But like I said, it’s way to complicated to explain everything, but I will be writing a post on this as part of the Ideal Routine Page on my blog. Here’s the publishing schedule: Anyways, it’s okay to use the two.

    If I may ask though, which specific prescription product are you referring to? Because I’m not familiar with a prescription product that contains both ingredients, at least not in the tUS.

  • dee

    Ive heard its also not a good idea to mix tretinoin and vitamin c. I dont know if the efficacy of my prescription is worth the price since it contains asorbic acid and tretinoin

  • You’re welcome! And stay tuned for the Ideal Routine Page that I will begin to publish on July 1st on my blog. Here’s the schedule if you’re interested:

    Those posts should hopefully answer any and all questions you have about your skin care routine. 🙂

  • Nikita

    Thanks John! I guess I’ll just try to find another way to incorporate niacinamide. 🙂

  • @Nikita

    I actually wrote a follow-up post in regards to the use of niacinamide and acidic ingredients like hydroxy acids here:

    Let me know if you have any questions after reading that.

    And yes, I really do like that the NCN product contains 5% NCA and NAG! However, I do NOT like that it contains 5% lemon peel. Therefore, I personally would not recommend that product.

  • Nikita

    Oh, also, what do you think of NCN’s Forumla 5-5-5? It has 5% niacinamide and 5% N-acetyl-D-glucosamine.

    Thank you!!

  • Nikita

    I was wondering, since I can’t use niacinamide with L-ascorbic, can I use it with an AHA? I use glycolic at night and a c-serum in the morning and want to start using niacinamide, so can I add it to my nighttime routine? I’ve tried to do a little research on this but can’t find any legitimate sources that give me a proper answer but you I trust!

  • @Chris

    That is a very astute observation! An anhydrous product has NO pH. However, your skin DOES have a pH. Therefore, when the two (NCA and LAA) come into contact in your skin, they will interact. Albeit, the rates of interaction/complexation will be lower. But really, there’s no benefit to using them together during the daytime; only potential disadvantages.

    Save niacinamide for your evening routine.

  • Chris


    Futurederm has launched an anhydrous Vitamin C serum; to my understanding, we cannot measure the pH in an anhydrous product.

    If I layer this Vit C serum over another topical product with niacinamide before retiring in the evening, do these two products form 1:1 complex and make each other useless?

  • @Sam

    Yay! I understand.

    And using niacinamide after your retinol is a very wise decision. 🙂

  • @A

    If you look through the comments again, and this post itself, you’ll notice that I said that niacinamide doesn’t have a meaningful interaction with vitamin C derivatives. Check out the comments I made to @Marie and @Joni above.

    Also, note that in the NCA/NTA post, the recommendations that I made aren’t the ONLY good products out there are contains niacinamide. They’re just a few that I selected. There are many out there!

  • Sam

    Yes, that does make perfect sense. Sorry, sometimes all this new information is a lot to cram in my brain!

    I understand you and so I will try to add niacinamide (not MN) into my routine, in the evening after my retinol so it doesn’t interfere with the L-ascorbic acid serum that I use every morning.

    Thank you again for being so very helpful!

  • A

    Hi John,
    I found this very interesting as well. I have also been using nia24 over CE Ferulic. Reading your answers, though, I went back and looked at the article comparing NCA and NTA. I want to continue to use the B3 at night (not over the vitamin c), but in your preferred form of niacinamide, but it looks like the product recommendations in that article for Olay ALL contain vitamin c derivatives along with the niacinamide. Given what you say in this article, does that make those poor alternatives? Any other ideas?

  • @Sam

    You’re welcome!

    Also, I’m not sure if you understood the article correctly… or maybe I’m not understanding you correctly. You DON’T want to use a sunscreen with niacinamide IF you’re going to use an L-ascorbic acid product underneath it. The complexation interaction discussed in this article is a NEGATIVE thing between NCA and L-AA; you DON’T want that to happen.

    Does that make sense?

  • Sam

    I meant to add that I will research a product that contains NCA plus a mineral-only sunscreen. If I find such a thing, I may have found something to trade my Nia24 100% mineral sunscreen for!

  • Sam

    Thank you so much for your very helpful reply!

    I thought that niacinamide WAS the ingredient in the NIA24 sunscreen – thank you for clarifying the difference between NCA and MN in that other very useful and well written article. I had no idea.
    This has been a big help.

    Thank you!

  • @Sam

    No, you should be okay with using both products at once. The interaction discussed in the above-mentioned article is only between niacinamide and L-ascorbic acid. The vitamin B3 form in the Nia24 sunscreen is myristyl nicotinate (MN), an ester of nicotinic acid. Very little of MN will convert to nicotinic acid, and very little of that (at least at one time), will convert to niacinamide.

    Therefore, there shouldn’t be many opportunities for the L-ascorbic acid and any eventually formed niacinamide, to interact with each other and form complexes.

    Does that make sense?

    On a side note however, I would prefer if you used niacinamide over MN, just because the former has so much more documentation and research behind it than the latter. See this post for more information:

  • Sam

    If I understand this article correctly, this is bad news for me!!
    I use the Timeless C+E Ferulic Acid serum every morning under the Nia24 Sun Damage Prevention 100% Mineral Sunscreen with 5% Niacin. Both have been recommended on this blog and I adore both products.

    So, does the above information render my Nia product useless? It’s obviously a daytime product and I have to use the Vit. C serum in the daytime too as I can’t use it at night with my retinol!
    Does this mean my Nia sunscreen has to get the boot?

    And thank you for such a well written article.

  • @Marie

    Sure, you’re welcome!

  • Marie

    Thanks for the answer!

  • @Marie

    Actually, and I’ve responded to several people asking similar questions, but you don’t have to worry about any meaningful interaction between niacinamide and the various vitamin C derivatives, which is what’s present in the Ultra-Light Serum. The negative interaction discussed above only occurs between L-ascorbic acid and niacinamide, AND is highly dependent on both pH and UV irradiation. So, I’d definitely recommend the Ultra-Light Serum! It’s got a great list of ingredients. 🙂

  • Marie

    I want to try one of Paula’s Choice antioxidant serums since the price is so good! However I’m currently pregnant and can’t use retinol, which she has in her Skin Balancing Serum and her other two serums seem that they could be a bit “heavy” for my very oily skin. Then I was very excited when I saw that she came out with a new Ultra-Light Serum for oily skin with no retinol, but I was looking at the ingredients and saw that she combined niacinamide and vitamin C, so essentially you wouldn’t recommend this product of that combination?

  • @Erik

    Thank you good, sir!

  • Erik

    Hi John,

    Thanks for the information. Your site along with this blog is chockful of good solid information. I will keep coming back to check on the latest and greatest. Cheers!

  • @Joni

    Sure no problem!

  • @Erik

    Well, your dermatologist told you to use something before your Retin-A to reduce sensitivity. This something will act as a buffer, which in fact, will reduce the efficacy of the Retin-A. That’s why you’re not experiencing as much irritation. However, how much a difference, is unknown.

    Now, the fact that you chose the CeraVe PM lotion as the buffer, is a good thing actually! Research has shown that if niacinamide is applied prior to tretinoin exposure, the side effects (like dry skin and irritation) are significantly reduced: And that makes sense, since niacinamide improves the epidermal barrier overall; plus there’s the buffer reduction of efficacy discussed above, which reduces the amount of tretinoin that reaches the skin.

    Also, while niacinamide and retinol have similar optimal pH values, you don’t have to worry about that issue because tretinoin operates fairly well across all physiologically relevant pH values.

    Does that all make sense?

  • Joni

    Great news, b/c I just ordered the PC toner! Thanks for putting my mind at ease! 🙂

  • Erik

    Really cool stuff in this article. Never thought about not to combine certain skincare products before.

    I have a question though. I am using generic Retin-A every night. Since my skin is sensitive, I was told to put on a moisturizer first and wait 20-30 minutes and then put on Retin-A.

    Since I use Cera Ve hydrating cleanser, I choose the Cera Ve PM lotion as my moisturizer prior to Retin-A application for budget reason. I just noticed that the PM lotion has niacinamide. Will this combo reduce the effect of Retin-A, since I don’t know much about ph balance and all that chemistry stuff?

    Definitely will start checking out more of your articles in your blog! Great article. Thanks.

  • @Joni

    You’re very welcome! And I’d definitely recommend the PC Skin Balancing Toner! I love using it on myself. It provides decent amounts of niacinamide, though not enough as a standalone source.

    As for it containing both of these ingredients, well I just looked at the bottle and it doesn’t contain both of them. There is a dash of a vitamin C derivative, tetrahexyldecyl ascorbate, but remember, the interaction discussed in this post is only between L-ascorbic acid and niacinamide at an appropriately low pH, which is required for L-ascorbic acid to properly dissociate, penetrate, and function.

    And as this article stated, you don’t have to worry much about any negative interaction occurring between niacinamide and the vitamin C derivatives.

    Does that make sense?

    I look forward to seeing more of your comments on future posts both here and on my blog!

  • Joni

    Hi, Thanks for all the great info. I have been reading you website for the past week nonstop! Truly informative! Based on this, would you still recommend PC Skin Balancing Toner? I noticed it has both these ingredients…

  • @Ann

    Thanks so much! I’m super glad to have you. And congrats on being the first comment on the second page. 😉

  • Ann

    Thanks, John. You ROCK!!!!! Count me in from now on to be one of your faithful blog readers. I am so tired of other skincare blogs that have a very narrow focus despite being written by medical professionals. 🙂

  • @Ann

    Thanks! I’m glad to have you. 🙂

    Well, the pH of Finacea (~ 4.8) is higher than that of most hydroxy acid products, which are usually between 2.5-4.0. And since the minimum non-enzymatic hydrolysis of niacinamide occurs at a pH of between 4.0 and 6.0, it should be fine to niacinamide with Finacea. So keep doing what you’re doing!

    You may want to check out this post for more information:

  • @Lucas

    Nope, that’s impossible as far as I know, at least if you were to compare the effects of that combination to those when using the two separately. Combining the two will always perfom less optimally.

  • Ann

    This is such a great article! I am glad that I stumbled on this web site.

    I am wondering if Azelaic Acid such as Finacea can be used at the same time with a moisturizer containing Niacinamide. I have been using Olay Regenerist Regenerating Serum, which contains Niacinmide as a moisturizer. Niacinmide helps with my sensitive skin tremendously.

    After reading this article, I am wondering if there’s going to be any ill effect of using Finacea and Niacinmide at the same time.

    Thank you!

  • Lucas

    Hi, John.

    My question is a bit off topic. I was wondering if it’s possible to formulate a product with niacinamide and glycolic acid, so that they are both effective.

    Thank you!

  • @AJ

    Great thanks!

  • AJ

    All agreed! Thanks again John! I look forward to your future, great informative articles! 🙂

  • @AJ

    I’m sure you know this but a high SPF and a high level of UVA (-PF) protection are both necessary!

    As for the Image website, when I mean full ingredients lists, I mean ones that list ALL the ingredients including the vehicular ingredients and is in descending order of concentration; not just the important or featured ingredients. That way I can better estimate how much of a particular ingredient is in a product. Also, I don’t think the reason they don’t sell in department stores is because of integrity, or at least not true integrity, as there are plenty of excellent products sold there. Perhaps they want to spread the “image” that their products are better as they are available exclusively from a estheticians, which of course is not true. But that’s all speculation.

    Regardless, full ingredients lists are necessary. But still, it’s great that you like the brand and enjoy the results their poducts give. I just prefer recommending and using products that are available to everyone (or at least to a larger audience), bcause it’s more practical.

    I hope to see more of your comments in future posts.

  • AJ

    Thanks for the quick response! Yes, makes total sense. I have other excellent
    SPF’s I should just stick with. I live at a high altitude, so SPF is so

    The Image website usual has full ingredient lists w/each product. Maybe that’s
    changed. It’s a neat line I started using a year ago & not as widely marketed/sold as some of the others. They don’t allow it to be sold online or in retail stores like Sephora, ULTA, etc. I think this protects the integrity of the products, although they’re harder to get. Check it out. It would be interesting to see what you all
    think, as skincare review experts. 🙂 I LOVE their Vital-C line & also MAX. Their price points are very reasonable. (You can find them on Amazon, but they’re not supposed to be sold on Amazon, so whose knows who does & how. It’s about the same cost as what I pay retail so I trust my esthetician & know I’m still getting quality product.)

    Thanks so much!

  • @AJ

    Thanks for reading!

    Yes, it’s fine to use myristyl nicotinate with L-ascorbic acid and tocopherol. The interaction explained in this article only occurs with niacinamide. On a side note however, I wouldn’t personally recommend using that particular Nia24 sunscreen since I don’t believe it provides enough protection against UVA1 rays. But’s it’s better than nothing.

    As for the Image serum, I can’t seem to find a complete ingredients list so I can’t really tell you my opinion of it. However, I can tell you that you can’t “over-brighten” the skin. This is just a buzzword generated by marketing teams. In fact, if you’re dealing with hyperpigmentation, it’s best to treat it with multiple types of lightening ingredients that work via different mechanism in order to compound the overall effect. So long as you’re not seeing signs of irritation, you’re not aggravating your skin by simply using many lightening ingredients,

    Does that all make sense?

  • AJ

    Hi John,
    Love your posts!
    Now, I’m confused….I recently read one of Nikki’s earlier posts where she recommends the Skinceuticals C+E+Ferulic as well as the NIA 24 Sun Damage Prev. Mineral Sunscreen. However, then I saw your post about not using niacinamide with Vit C, so I’m a little concerned. I know this NIA24 has nicotinate, so is it ok or could it still have the same issues with being “rendered useless”?
    Of course, I don’t want to use these together & waste $$ or cause any bad reactions with my skin.

    Also,while I’m at it….I use Image Skincare’s (natural) lightening serum (PM only). It’s main ingredients are rumex, kojic acid, green tea, vitamin c (low on the list) and other natural ingredients. Would it be redundant to use this at night for “lightening/brightening”, then the NIA24 SPF during the day? I don’t know if I can really over “brighten”, but again don’t want to aggravate my skin. I have minor sunspots and a few acne spots (that take months to go away), which is why i’ve started using the lightening serum. I’m 45, live in the high desert & am diligent with my SPF, but am always looking for something new that may add add’l prevention. I’ve used Dermalogica’s Agemart Dynamic Skin Recovery (w/spf) for a couple years and need a change… I’m told I don’t look my age and want to keep it that way! 🙂

    Thanks so much,

  • @Simona (Sânziene şi Mătrăgună)

    Well, the main reason why I didn’t say it was very good was because there was such a lack of personal reviews and the existence of a mild packaging issue. However, I stand corrected by the manufacturers, and there will be a very, VERY exciting event happening soon on this blog.

    I can’t say much yet, but stay tuned!

  • @Linda

    Wow, I’m so flattered! Thank you for the support. I hope to never disappoint you guys. 😉

  • @ chloe , @John

    About the Medik8 CE Tetra serum – why wouldn’t it be a good choice? I love tetrahexyldecyl ascorbate, it is at 7% (max usage rate), it has a penetration enhancer.. Of course that for the same price some other very nice oils could have been included there…

    My night oily serum is a kind of a replica of this one, 7% tetra, 7% dicaprylyl carbonate (as penetration enhancer), 1%d-alpha tocopherols,1% bisabolol, 1% Q10 (at 3% dilution in squalane) – and for the rest of the oils I get creative 🙂

  • Linda

    Thanks again, John! Quick response, I’m sure your responses and further clarification in the comments section help others with their research like they do me! I’ll be buying the Glytone Step 3 Lotion next, for sure! Best to you. I have cancelled all my email blog subscriptions because it’s just too much to follow, however, I just signed up for email alerts on your own personal blog htttp:// which is a salute to you! What an amazing and generous resource you are…..:)

  • @Linda

    I’m super flattered!

    Well, I don’t like any product that’s packaged in a jar. However, the chief reason why is because it allows air to degrade any air-sensitive ingredients such as antioxidants, etc. However, hydroxy acids tend to be decently stable when exposed to air. Would I prefer that HA products be packaged in tubes and pump bottles? Yes, but really, a jar won’t significantly alter the efficacy of the glycolic acid content. So that’s good news: you can stick with the Glytone Step 3 cream! I mean, you obviously have had good results with it.

    But if you’d like some options, have you tried either the Glytone Step 3 Lotion or the Body Lotion? They both contain 17.5% GA in lighter bases; and they’re packaged correctly. You may want to give those a try.

  • Linda

    Hi John, I’m starting to think you’re the consummate expert on skin! Even though this comment may be off topic from the article, it’s in line with the direction some of the comments have taken. I alternate CE Ferulic with CRS 15% during the day, topped with one of your approved sunscreens and I alternate Retin A micro with Glytone cream 20% 3 ph (thick cream in a jar) every night sometimes throwing in a little DDF Glycolic toner from time to time (just not before Retin A). I just lost faith in the Glytone now that you have shared that you believe a jar is not good for glycolic if it’s not used quickly. The Glytone lasts forever. I researched your articles further and read your full series on AHA’s and found that liquids and gels and a low ph are good when using glycolics. The glycolics you recommend are much lower % than what I have carefully worked up to with the 20% Glytone. I tolerate it fine now and don’t want to drop down the % since I can tolerate it. Since you don’t like open jars and creams as much, do you have a glycolic that you like better that’s at a higher %? Is the Glytone a waste? I don’t feel I need to have a multi tasking glycolic product (like some of your recommendations) since I seem to have my bases covered in the antioxidant/sunscreen/retin A arena. I also never know how or when to throw a moisurizer into this mix. These skincare products are so expensive when you add it all up that it’s important to do our research!

    Thanks in advance for anything you have time to share!

  • @Chloe

    The peptide in the first product does not have any proof, so there’s no point of using it.

    The second product is very good, but way too expensive since the bottle only contains 0.3 oz.

    The third product is very good, but I actually haven’t used it for months. I have been using a vastly different routine and have yet to update it online.

    The fourth product is also good, though calcium ascorbate most likely won’t convert to L-ascorbic acid. The inclusion of some potentially irritating essential oils may make it inappropriate, but you can definitely give it a try! If you do use it during day, do use a good sunscreen after.

  • @Marla

    I haven’t heard that you shouldn’t use niacinamide with benzoyl peroxide. Niacinamide is one of the more stable topical ingredients, and shouldn’t be affected by the mild oxidative prowess of benzoyl peroxide.

    However, if you’d like to wait 30 minutes before application time, that’d be fine too. But not because its absoprtion time is 30 minutes, since that will vary from person to person, and formulation to formulation.

  • Chloe

    Thanks John. I was spending sometime last few days looking at products and found below. Which one you think will suit me best? (my skin type: asian, minor hyperpigmentation, somewhat sensitive, dry)

    Dermalogica ChromaWhite TRx C-12 Concentrate

    Dermalogica Age Smart MAP-15 Regenerator

    Paula’s Choice RESIST Super Antioxidant Concentrate Serum (you use this reading your blog?)

    OLE HENRIKSEN Truth Serum® Collagen Booster (This one has citrus and I wonder that won’t be so good to use under the sun?)

    Thanks again! 🙂

  • Marla

    What about using a moisturizer, like CeraVe PM (which lists niacinamide as its fourth ingredient) on a nightly basis after using a topical 2.5% benzoyl peroxide gel to treat acne? If BP is an oxidizing agent, would that present a compatibility problem with niacinamide? I had read that most of the BP is absorbed by the skin in the first 30 minutes, so would you recommend waiting over 30 minutes before applying moisturizer over skin that has had BP 2.5% applied to it? Thanks.

  • @Chloe

    Hm, I don’t like the first product because very, VERY few people have used it before. Plus, the manufacturer doesn’t release any relevant data. One aspect to consider is how reputable a manufacturer or company is. I wouldn’t recommending buying from some small company that no one’s heard of. But that’s just me.

    The second product is packaged in a jar… so that’s out of the question.

    Try using Beautypedia and type in the vitamin C derivatives that I mentioned before into the search bar. Then you can narrow/organize by rating, type of product, etc… It’s not a perfect tool, but it is very useful. Then read the ingredient list of products that you’re interested in and make sure that the vitamin C derivatives are relatively close to the top. We can then go from there!

  • Chloe

    You are a SUPER STAR!!! Thank you so much! When you get a chance, it will be amazing if you did an article about different forms of Vitamin C with product recommendations. : ) I googled around but only found two products below. Do you have any recommendations please???

    Medik8 CE-Tetra — Simmondsia Chinensis Oil, Tetrahexyldecyl Ascorbate, Cyclopentasiloxane, Cyclohexasiloxane, PPG-12/SMDI Copolymer, Tocopherol Acetate. Tetrahexyldecyl Ascorbate 7%, Tocopherol Acetate (d-alpha vitamin E) PPG-12/SMDI Copolymer (PP- 2)

    Perricone MD Cold Plasma — Aqua (Water), Glycerin, Tetrahexyldecyl Ascorbate, Phosphatidylcholine, Isopropyl Palmitate, L-Tyrosine, Butylene Glycol, Glyceryl Stearate, PEG-100 Stearate, Cetearyl Alcohol, Oligopeptide-17, Ceteareth-20, Magnesium Aspartate, Zinc Gluconate, Dimethyl MEA (DMAE), Docosahexaenoic Acid, Ascorbyl Palmitate, Phenoxyethanol, Dimethicone, Caprylyl Glycol, Glycolic Acid, Retinyl Palmitate, Saccaromyces Ferment, Elaeis Guineensis (Palm) Oil, Carbomer, Disodium EDTA, Tocotrienols, Copper Gluconate, Polysorbate 20, Sorbic Acid, Tocopherol, Sodium Hyaluronate, Acetyl Hexapeptide-8, Palmitoyl Oligopeptide, Astaxanthin, Palmitoyl Tetrapeptide-3)

  • @Chloe

    Well L-Ascorbic Acid can certainly be irritating, with its low pH. If you can tolerate it, consider using a vitamin C derivative. Look for high concentrations of the forms tetrahexyldecyl ascorbate (ascorbyl tetraisopalmitate) or magnesium ascorbyl phosphate. Sodium ascorbyl phosphate is okay too!

  • Chloe

    Hi John,

    Sorry to write a bit of off topic, but I find my skin gets red and sensitive to L-Ascorbic Acid. I tries a bunch of different companies and all of L-Ascorbic Acid serum irritates my skin. Nikky and you both seem to like L-Ascorbic Acid effect on the skin. Is there any second best form or vitamin C I can try out?

    Thanks!!!! 🙂 Chloe

  • @Trae

    You always write such comprehensive responses. Nice work!

    Yeah, nicotinic acid is never applied to the skin so its discussion is pretty much irrelevant; another thing that I don’t agree with the post. But anyways!

    As for the growth factors question, my biggest concern isn’t whether or not weak acids such as glycolic acid can denature these proteins, which they can depending on how much of the hydroxy acid product is applied, how much hydroxy acid is present, and how low the pH of the product is.

    My biggest concern is if these growth factors can actually be delivered into the skin in efficacious amounts, since most growth factors are massive in size (TGF Beta-1, which is what the Citrix product contains has a molecular weight of 25,000 daltons; most ingredients without a delivery system have to be less than 500 daltons to penetrate the stratum cornenum; not to mention solubility, polarity, etc), is the inclusion of these growth factors in skin care a good thing?

    I actually responded to a reader on my blog about this topic. Please see the comment by Robyn and my response to her in this post:

    Let me know what you think about that, and as always, you’re very welcome!

  • Trae

    Thanks for the reply, John ^_^

    That actually makes for a great generalized saying: overthinking > not thinking LOL.

    I suspected that there might not be much of an issue with retinol and myristyl nicotinate because in the article that recommended against combining retinol and nicotinic acid, Nicki explicitly wrote ‘nicotinic acid’ and not ‘myristyl nicotinate’, but I get paranoid about these things, as you can see -_^

    I found your response to Janine’s first comment reassuring with regards to the first part of my question where I mentioned that I’d moved my L-ascorbic acid serum to nights (after AHA), at the same ‘end’ of the day during which I apply my myristyl nicotinate product: in her first of two comments Janine mentions that she uses C E Ferulic serum before applying a NIA 24 product, which is similar to my use of an L-AA serum preceding myristyl nicotinate, which is why I found your response to that particular comment of hers to be comforting, particularly since I’m employing a wait time after the L-AA and not applying either when I’ll be exposed to UV. If future studies show that a similar issue exists between a nicotinic acid and ascorbic acid combination (to that which has already been demonstrated between niacinamide and ascorbic acid) I could always just use my myristyl nicotinate product only on nights that I don’t apply ascorbic acid — i e the ‘nonacid nights’.

    Since we’re on the topic of overthinking things and my paranoia regarding product combinations, what’s your opinion on using a growth factor product like SkinMedica TNS Recovery Complex with acids like ascorbic or glycolic ? Skin Medica’s website suggests these products being used in regimens together, and Topix Pharm’s Citrix line includes an anhydrous ascorbic acid product that also contains epidermal growth factor in the same product…what was concerning me was the idea that proteins (how I’ve seen derms describe TNS — as ‘containing proteins’) could be denatured by acids, but info I could find on denaturation states that it tends to occur mostly with strong acids and bases, which glycolic and ascorbic acid are not, if I remember correctly (I only had to take a couple of semesters of chem undergrad, and that was several years ago, so I definitely could be wrong -_^). Since I’ve never seen TNS Recovery Complex turn cloudy (or any other sign I usually think of with protein denaturation) when applied over AHA and ascorbic acid after a 30 minute wait time, I’m not too worried about it, but it’d still be nice to get a definitive answer LOL.

    Thanks again for the reply and for quelling my fears regarding these pesky ingredient combinations -_^

  • @Trae

    You are overthinking it! But I’d rather you do that than not think at all. 🙂

    You don’t have to worry about using retinol with myristyl nicotinate bcause the skin slowly converts the former into nicotinic acid via esterase enzymes. The amount present in the skin at any one moment is most likely too small to influence the pH of the skin, even temporarily. Therefore, the optimal conversion of retinol to tretinoin, which is dependent on pH, will not be meaningfully affected. However, waiting between applications can’t hurt so you might as well if you can.

    Your question is not quite the same as janine’s, since the interaction between niacinamide and L-ascorbic acid is a physical conformational change, while that of nicotinic acid and retinol involves pH ranges for optimal conversion. Still, I’m glad that my response to her made you feel better!

  • Trae

    Oops ! I just now looked at the previous page of comments and saw that Janine’s question was essentially the same as mine (my bad LOL ._.). Your response to her makes me feel a lot better about using these on the same night with a wait time in between. Thanks for all the work you do here and on your blog (articles + answering questions): it really makes a great collective reference when it comes to designing one’s skincare routine ^_^

  • Trae

    Hey John !

    I have another question (sorry, I’ve been asking you a lot lately LOL -_^). I restructured my regimen back to an alternating night one, like I described in my comment on the article ‘Can You Really Use Retinoids with AHA, BHA, and L-Ascorbic Acid or Not?’ and have been using that for a couple of nights with really good results…but I think I may have run into a caveat :'(

    By designing my regimen this way, it moves my L-ascorbic acid serum to every other night immediately after my leave-on glycolic acid product, and I employ a minimum 30-minute wait time afterwards (sometimes up to an hour) before applying the next product, and the last product I apply is usually a myristyl nicotinate product from NIA 24, so I’m not sure if that could interact with the L-ascorbic acid (the form I’m using is not technically niacinamide, but it *is* a form of B3, so it’s worrying me :-/). Additionally on the non-acid nights when I use retinol and GHK-Cu, I’ve always applied my NIA 24 product as well, but I’ve read another article on FutureDerm suggesting that it’s not a good idea to use retinol with nicotinic acid (which myristyl nicotinate converts to, if I understand correctly), though using my myristyl nicotinate product has never seemed to diminish the strength of my retinol product (I added in the NIA 24 in years after I’d begun using retinol).

    Am I overthinking all of this or should I move more stuff around ?

    Thanks in advance ! ^^,

  • @Confused Girl

    Your routine looks fine. As I’ve indicated in the post and the many responses to people in the comments section, the likelihood of a significant interaction occurring between vitamin C derivatives and niacinamide is very low. This is because the vitamin C derivative has to first convert to L-ascorbic acid inside the skin. And since this negative interaction occurs most often at a pH of 3.8, the skin’s pH is nowhere near that low. Also, the amounts of both ingredients present aren’t very high, especially for niacinamide in the nighttime product. You don’t have to worry about the daytime routine since both ingredients aren’t applied within a close time proximity.

    Does that make sense? Keep up with your routine!

    Also, in the Ideal Routine Page on my blog, I’ll be listing common interactions that people should be aware of! So stay tuned. 🙂

  • Confused Girl

    An utterly fascinating post, albeit a little late for me. I just bought a serum with with MAP and niacinamide to use after a weekly home salicylic/lactic acid treatment (that I do at night).

    What do you think of these ingredients applied at night:

    Distilled water, sea kelp bioferment, sodium PCA, magnesium ascorbyl phosphate, pomegrananate extract, natural active peptides, hyaluronic acid, l-carnosine, boswellia serrata, niacinamide, n-acteyl glucosamine, centella asiatica, horse chestnut extract, betulinic acid, green tea ECGC, epidermal growth factor BT, germaben II

    Should I use it?

    Also, my current am routine is to apply sunscreen and antioxidant serum, both containing vitamin C derivatives, then several hours later to wash it off with water and apply a retinyl acetate/niacinamide-containing moisturiser and then a 4% nicotinamide gel on top.

    The sunscreen:

    Zinc Oxide 19%
    Inactive Ingredients:Aloe barbadensis (aloe vera gel), Water (purified), Camellia sinensis (Japanese green tea) leaf extract, Capric/caprylic triglycrides (derived from coconut oil), Glycerin (vegetable), Butyrospermum parkii (shea butter), Olea europeaea (olive) oil, Lecithin phospholipid, Hyaluronic acid (vegan source), Simmondsia chinensis (jojoba) seed oil*, Squalane (olive), Panthenol (vitamin B5), Tocopherol (vitamin E), NaPCA, Rose moschata (rose hips) oil, Retinol (vitamin A), Centella asiatica (Gotu Kola), Copper gluconate, Magnesium ascorbyl phosphate, Fucus vesiculosis (seaweed) extract, Allantoin, Sodium riboflavin phosophate, Chondrus crispus (Irish moss), Lavandula officinalis (lavender) essential oil, Anthemis nobilis (chamomile) flower essential oil, Vitis vinifera (grape) seed extract.

    The antioxidant serum: pomegranate seed oil, rosehip seed oil, alpha-D-tocopherol, lycopene, tocotrienols, astaxanthanin, lutein, alpha lipoic acid, ascorbyl palmitate

    If I’ve understood your post correctly, I wouldn’t have to worry about a pro-oxidative effect with the vitamin C derivatives, just reduced efficacy of both compounds. Or would both still occur?

    Anyway, I’d really be interested in hearing your advice. Would you contine with this regimen?

    I just wish someone would publish a book for laypeople detailing all of these sorts of interactions…

  • @Lucas

    You’re welcome! Keep up the good work.

  • Lucas

    Yeah, I got it!
    I guess it’s not a serious concern, but I was just curious really. I won’t worry about this.

    Thanks again, John!

  • @Lucas

    Well, they antioxidants will most likely have a greater synergistic effect if they’re in the same product, rather than in separate ones because the former helps ensure that the vitamin C and E are homogeneously mixed in order to allow for optimal “recharging” via reduction interactions. This reduction interaction is dependent on a variety of factors; its redox potential can be affected by things such as pH and concentration.

    So while it would be best to use a product that contains both (and is properly formulated), you’ll still be getting some sort of beneficial interaction between the two antioxidants even if they come from two separate products. It is just unknown how small or large of a difference that would make on the overall level of protection when compared to if they were in a single well-formulated product.

    Does that make sense?

    My biggest recommendation is to relax. Don’t stress out over this rather small issue. As someone who’s answered many of your questions, I know that you’re taking excellent care of your skin. Is it really worth worrying about 90% vs 91%? It’s all about balance. As long as you’re taking care of your skin, eating right, exercising, not stressing out, sleeping right, etc… your skin will take care of itself!

    I hope that helps.

  • Lucas


    My question is a bit off topic, but it’s still about L-Ascorbic acid!
    Vitamin C should be used with vitamin E to enhance its photo-protective properties, right?! But do they have to be on the same product/container? Or using one product with L-ascorbic acid and another one with vitamin E do just the same?
    I’m asking because I’m thinking about trying a serum with 10% L-Ascorbic Acid (but it doesn’t have vitamin E) and my sunscreen already has 1% vitamin E, so would it add up once it’s on the skin and do the same think as if I used a product with both?


  • @Anya

    Yes, again while I would prefer if you used the two separately, you are correct that the amount of niacinamide present in the PC product is most likely negligible. 🙂 So if you’re satisfied with your routine, keep doing what you’re doing!

  • Anya

    Hi! I use Cosmetic Skin Solutions C+E Serum, followed by Paula’s Choice Moisture Boost Hydrating Treatment Cream, which has Niaminicide listed in the middle of the ingredients list. It also has a stabilized form of Vitamin C in it. Is it okay to use these products together (or only about 10 min apart) since the amount of Niaminicide in the PC product is relatively small? Thanks in advance for any info you can provide, and thanks for the great post!

  • @kaye

    The PC BHA 9 isn’t really supposed to be used all over the face on a daily basis. Think of it as a spot treatment alternative to benzoyl peroxide. But yes, I really like the 2% BHA Liquid; though it is a tad “oily” feeling. You may want to try the CLEAR 2% Regular Strength BHA. It’s more watery, though less effective.

    I also addressed your concern about having to wait 30 minutes in my latest post:

    So with that in mind, I think you should cleanse, apply the BHA, wait 30 minutes, then apply the glycolix and sunscreen. Does that make sense?

    Thanks for reading my story and routine! However, that hasn’t been updated in a long time; both my story and routine. I’ll be adding to the story and coming out with an updated skin care routine (which I’ve already been using for the past few months) in the near future. So stay tuned if you’re interested!

  • kaye

    Thanks for the reply John! Happy Halloween to you too 🙂

    Thanks for the recommendations, I really value your opinion.

    I’ll keep the Glycolix Facial Cream as is for now.

    But I’m thinking of taking out the Dr. Gross Peel and adding the new Paula’s Choice Resist BHA 9. I use futurederm retinol and just started 4% hydroquinone– I use them both at night.

    So my morning would be cleanse, dr. gross peel, glycolix facial cream, sunscreen. I have acne that I’m trying to get rid of which is why I’m using the dr. gross peel. Benzoyl peroxide I’m using on and off too. But I’ve noticed that what really helps is keeping my pores exfoliated so I’m focusing on that.

    Dr. Gross Peel is expensive and I have a feeling that it’s mainly salicylic acid that I need. Would you recommend using Paula’s Resist BHA 9 or even Paula’s Skin Perfecting 2% BHA instead of the Dr. Gross Peel? So then I would cleanse, apply BHA, wait a few minutes, apply Glycolix Facial Cream, wait 30 minutes, then apply sunscreen.

    How’s that sound? I’m a little concerned the Glycolix Facial Cream would prevent the BHA from penetrating, but I’m told applying moisturizer within several minutes of cleansing is key. I want to incorporate moisturizer because using retinol, hydroquinone (for a limited time), and using BHA are all drying. And my Elta MD sunscreen is one that I love and I kind of refuse to buy a more moisturizing one 🙂

    P.S. I read your story and routine on your blog. All I can say is WOW! You’re amazing!!

  • @kaye

    No, the glycerin and dimethicone will not prevent the hydroxy acids from penetrating because they are applied after the Dr. Gross Peel. So there is no risk of an occlusion-based reduction in efficacy. However, what will reduce the efficacy is actually the peel itself: it’s pH is a bit too high at 4.4, which won’t allow for meaningful exfoliation. The tightening and burning sensations that you’re feeling is from the alcohol and witch hazel contents, NOT from the hydroxy acids. And don’t even get me started on the Step 2 part. Its alkaline pH will neutralize the many potential beneficial ingredients, not to mention that it’s packaged in a jar.

    And speaking of jars, the Glycolix one is packaged in a jar too, which is never a good thing. 🙁

    It’s recommend for you to find replacements products. But just do the best that you can.

    Thanks for reading and commenting!

    Happy Halloween!

  • kaye

    wow i use the Dr. Dennis Gross Alpha Beta Daily Face Peel and Glycolix Elite Ultra Lite Facial Cream too!!

    i apply the Alpha Beta Peel Pads first…..then wait for a couple of minutes….and then apply the Facial Cream. my concern was actually that the Facial Cream would prevent the Alpha Beta Peel from penetrating

    the ingredients of the Facial Cream are:

    Aloe Vera, Emulsifying Wax, Glycerin, Squalane, PPG-2 Myreth Propionate, Dimethicone, Superoxide Dismutase, Green Tea Extract, Phospholipids, Retinyl Palmitate, Ascorbyl Palmitate, Tocopheryl Acetate, Coenzyme Q10, Beeswax, Benzyl Alcohol, Carbomer, Triethanolamine, Methylparaben, Propylparaben, Imidazolidinyl Urea.

    I was concerned that the glycerin and dimethicone would prevent the Alpha Beta Peel from penetrating the skin.

    p.s. it’s so interesting going through these comments and see how a lot of your readers use similar products!!

  • @Alina

    I actually recommended this product a few times to various readers in this post, so I think it’s a pretty great product. I can’t comment on whether or not the PC team actually know about this information, but regardless of that, there won’t be any interaction in the bottle.

    That’s because the interaction is only between L-ascorbic acid and niacinamide. Tetrahexyldecyl ascorbate does not interact with niacinamide, since the four palmitic acid fatty chains are occupying all the potentially sensitive “chemical sites” so to speak. TA only partially converts to L-ascorbic acid after it’s penetrated into the skin. Therefore, this complexation interaction may however occur inside the skin. But since this interaction is pH dependent, it will occur less than if L-ascorbic were used, since the pH of the skin is higher than 3.5.

    Does that make sense? For additional information on this topic, read Sânziene si Mătrăgună’s first comment, and my response to it. It’s on the first page of comments. 🙂

    And considering all the other beneficial ingredients in the PC Pure Radiance Treatment (N-acetyl glucosamine, mulberry, licorice, etc…) it’s a potent product that helps combat hyperpigmentation via different pathways. I gets a thumbs up from me. So definitely pick up some samples if you can.

  • Alina

    Dear John,

    How about Paula’s Choice new product – RESIST Pure Radiance Skin Brightening Treatment ? It has both Tetrahexyldecyl Ascorbate and Niacinamide. I am now quite confused about buying it or not. It wonders me why would they use these two ingredients together, taking into consideration they probably know the information you gave in this article.


  • @Annika

    I really appreciate your support! It means a lot. 🙂 And let us know how you like or dislike our retinol serum. I hope it works out for you.

    But getting to your question:

    It’s not a BAD thing to use L-ascorbic acid and niacinamide (and to a certain extent nicotinic acid; though it’s unknown how much of an extent; see other comments for more details) together because you will still be getting most of the benefits of both. However, it’s just BETTER to use them separately so there isn’t any negative interaction. So I’d say to keep using your Strivectin cream at nighttime after the retinol serum, and your CE Ferulic one during the day. When it comes to sunscreens, the ones I recommend can be found here:

    Depending on your skin type and preferences, you’ll want to pick something from either the dry or oil categories. Apply that product around 30 minutes after the CE Ferulic serum.

    But yeah, your routine looks fine. And while I think our retinol product is pretty good, you may want to see a dermatologist and asked to be put on a prescription retinoid, which are more potent and can affect more change than retinol.

    I hope that helps, and let me know if you have any more questions! Best of luck.

  • @France

    Phew, that relaxes me. Lol! And once again, you’re very welcome.

  • Annika

    Dear John,
    I have followed this site for a few months now and I am really impressed by the level of information and guidance you provide.
    Impressed enough to totally have changed my skin care routine and have the Futurederm Retinol cream sent across the globe to Sweden where I happen to live.
    I have always had poor skin which could be described as sensitive, dry and acne prone and in the recent years, starting to show lines and dark spots as well as some sagging.
    My new routine includes a serum with c+e+ferulic acid for morning use and the Retinol cream for evening and now to my question. I have intended to combine these creams with my Strivectin SD cream (8% Nia) morning and night, is that a bad idea? Reading your post I get a bit worried. Must also tell you that I’m now suffering from some increased dryness but hope this will be a phase passing. If the Strivectin cream is alright for the evening, what would you recommend for the morning (would love something that includes sunblock as I’m now adding this separately).
    Would be very greatful for your advice.
    Best regards

  • France

    Thank you, John, for your response! It definitely does help a lot. And I will try to relax more 😉

  • @casey

    Your routine looks pretty great! I love that you’re so detailed haha! And no, the peel and L-ascorbic acid will not cancel each other out, though the pH of the peel is a bit too high. However, I’d say to just keep your routine as is since it looks fine. The two together may be a bit irritating for your skin. They can be used together, but there is the risk of unwanted irritation. Make sure to wait around 30 minutes after you apply the Glycolix, and before you apply the PCA skin sunscreen.

    But other than that your routine looks good. The only thing I would recommend is for you to take out the Glycolix Cream at night-time and instead use something that contains a lot of niacinamide. The Glycolix Cream has some okay ingredients, but it’s packaged in a jar, which is never a good thing. See my list of niacinamide recommendation if you’d like an idea of what to use:

    Thanks so much for reading and commenting!

  • @Berk

    Thank you very much! I actually answered your question about the half-life issue in my response to France right above. Make sure to read that.

    And no, I would not recommend applying Vitamin C every other day. And if you like the EltaMD, check out the PCA skin dupe I recommended. The two products are virtually identical.

    Finally, I wish Dr. Bailey would write more for FutureDerm! She has some great information, and she’s only written one post so far. 🙁

  • @France

    First comment:

    It is OK to use glycolic acid during the daytime. However, it is preferred for evening use, just because it does slightly increase the skin’s sensitivity to the sun. I mentioned this in my hydroxy acids series, specifically in part III. Have a read if you’re interested:

    But considering the antioxidants and sunscreen, this slight increase in sensitivity shouldn’t have too large of an impact. I too only use glycolic acid at nighttime, but for Nook, I just didn’t want to change her routine too much. Is Nook even a girl’s name? Lol. Anyways… moving on.

    It’s not that niacinamide CAN’T be used below a pH of 5, it’s just that that some of it may convert to nicotinic acid, which may result in some redness and flushing. However, I think that the 5-7 pH range was given ith the idea of “better safe than sorry” in mind. But in reality, it has little relevance. For example, this study:, indicates that the MINIMUM conversion rate happens when the pH is between 4 and 6. So, glycolic acid products are typically formulated between pHs of 3 and 4. And waiting 30 minutes after application (something that I recommended for all acidic products), should take care of this interaction. And from personal experience (I use a glycolic and/or salicylic acid product at nighttime, wait 30+ minutes, then apply a niacinamide product) I have never experienced noticeable skin flushing, which suggests that no significant amount of nicotinic acid was formed.

    Does that make sense?

    As for your routine: You already know that I’d would prefer for you to use a non-niacinamide sunscreen, but hey, it’s completely your choice! It’s still way better than using no sunscreen. The 30 minutes wait time may theoretically reduce the complexation interaction between L-ascorbic acid and niacinamide, but that’s just it. We don’t know; can only hope for the best.

    But the rest of your routine seems fine.

    Second comment:

    Relax! Don’t freak out. While the half life of vitamin C is 4 days, you have to remember that measurement is theoretical and in the absence of things that degrade it: for example sunlight, oxidation processes that occur all the time in the skin, and other sources of free radical generation. So the vitamin C content in your skin doesn’t stay static and at the same level in real-life scenarios because it’s constantly being used up. I mean you want to protect your skin as much as possible, right? So it makes absolutely no sense to only apply vitamin C every 4 days. It’s a ridiculous notion.

    As for using glycolic acid with L-ascorbic acid, I have no idea why Dr. Bailey would say that. There is absolutely no documentation that supports her claim. Furthermore, when she responds to the various people asking her about it, she doesn’t show any evidence nor explain WHY they can’t be used together. I can think of no reason why they can’t be used together, except for the fact that some glycolic acid products are formulated with a pH above 3.5; they don’t typically go above 4.0 however. Now, a pH of 3.5 or less is recommended for L-ascorbic acid to properly penetrate into the skin. However, that number isn’t absolute. The diction makes it sound like a product with a pH of like 3.51 would be completely useless. And that’s not true at all. L-ascorbic acid is like any acid; it obeys all the same rules. Not to get too much into detail, just know that L-ascorbic acid can definitely be used with glycolic acid. I mean, L-ascorbic acid’s pKa is 4.17, while glycolic acid’s is actually lower: 3.83. I’ll definitely be doing a complete post on this in the near future. I may make it a two part series; we’ll see.

    But in the meantime, here are two brief examples to ease your mind: Both the two phrases that Dr. Bailey quotes: “Vitamin C has a half-life of 4 days” and “L-ascorbic acid requires a pH of 3.5 or less to penetrate the skin” are from studies done by the people behind the brand Skinceuticals. Here’s one of their studies: Now, if L-ascorbic acid isn’t compatible with glycolic acid, why in the WORLD would Skinceuticals include a product that contains BOTH ingredients?! Clearly, they can be used together.

    Finally, as for the niacinamide, just try not to use it together with L-ascorbic acid. Forget the half-life in 4 days thing with L-ascorbic acid. It has no significant relevance.

    I hope that helps!

  • France

    After writing my comment above, I looked up a link that someone else posted about Vitamin C’s “half life”, and found the following information in Dr. Bailey’s blog: “…vitamin c and glycolic acid can’t both be on the skin at the same time…”, and then, even more confusing: “The half-life of vitamin C in the skin is four days, meaning it sticks around for a while.”

    Wow, I am so confused now! If it is true that vitamin C stays in the skin for 4 days, then maybe Niacinamide should not be used at all by someone who uses a vitamin C product?

    Also, what do you think about the use of glycolic acid and vitamin C together, taking into account Dr. Bailey’s comment above?

    Here is the link to Dr. Bailey’s blog, where I found this info:

    Thank you so much John for taking the time to read everybody’s comments and replying… Peach wrote “I trust you” at the end of her comment above… I feel the same!!!

  • casey

    Had no idea about any of this, you’re awesome. and thanks for taking the time to read all of our routines.

    This is mine:

    MORNING: Mondays, Wednesdays, Fridays

    1. cleanser
    2. Dr. Dennis Gross Alpha Beta Daily Face Peel
    3. Glycolix Elite Ultra Lite Facial Cream
    4. PCA Skin Weightless Sunscreen

    MORNING: Tuesdays, Thursdays, Saturdays, Sundays

    1. cleanser
    2. CRS 10% L-Ascorbic Acid
    3. Glycolix Elite Ultra Lite Facial Cream
    4. PCA Skin Weightless Sunscreen


    1. cleanser
    2. FutureDerm retinol
    3. Obagi 4% hydroquinone
    4. After the 4 month mark (I’m still on month 1), I will take out the hyqroquinone, and simply use Glycolix Elite Ultra Lite Facial Cream after FutureDerm retinol. I’m using the hydroquinone to fade my acne pigmentation.

    I use the Dr. Dennis Gross Alpha Beta Daily Face Peel because it prevents acne and blackheads better than most products I’ve used, including Paula’s BHA. It also reduces the appearance of my large pores and brightens up my face. The directions say you can use it in the morning. I use it about 2-3 times a week (non-consecutive days). On the days I use this Peel, I do not use my L-Ascorbic Acid. I’m wondering though…what happens if I apply the Peel and then apply the L-Ascorbic Acid and then Moisturizer and Sunscreen? Would the Peel and Ascorbic Acid cancel each other out?

  • Berk

    This is such a great post! John, you are truly gifted in skincare!

    Reading this reminded me of the fact that topical Vitamin C has a half life of about 4 days on the skin. Would we benefit from applying Vitamin C every other day then? Maybe some of us who like Elta MD (possibly more than PCA?) can only apply Vitamin C twice a week with the Elta MD?

    I heard that statement from Dr. Cynthia Bailey’s blog, who also happens to be a FutureDerm contributor!

    ^Her statement about half life is in the comments section

  • France

    Hi John,

    I have a question that relates to your response to Nook above. I also use glycolic acid, but in the evening. I thought its use in the morning was NOT recommended? Is it actually OK to use it in the morning, as long as I use a sun block afterward?

    Also, I read (in this webpage: that Niacinamide cannot be used at a PH below 5, so I assume that it cannot be paired with glycolic acid either, right?

    Taking all of this into account, would you approve of the following regimen?

    AM: Glycolic acid product + vitamin C product followed by a 30-minute-wait, and then: Olay moisturizer (Complete Sensitive Skin SPF 30) with Niacinamide (I should find another sun block without Niacinamide, but I’ve used this one for years and love it so much… I know you recommended the 30-minute-wait to others above, so I am hoping this will work…)

    Evening: Retinol product + Olay serum with Niacinamide

    Thanks in advance John for your invaluable advice!


    Your idea to create an “ideal routine” portal/page for all skin types on your blog sound like pure genius to me!

  • @Nook

    There isn’t any known negative interaction between L-ascorbic acid and glycolic acid. In fact, since they’re optimal pH ranges are so close to each other, you might as well use them together if you’d like! And you don’t even have to wait between applications! 🙂 The two actually work together very well.

    See, the glycolic acid thins the stratum corneum, which will allow the L-ascorbic acid to penetrate even more deeply and at perhaps a higher rate.

    When it comes to your routine, I personally don’t love the DDF formulation because of the high amount of alcohol. It’s inclusion isn’t SO bad. However, since it’s a toner, it doesn’t really contribute a significant value to the product as a whole; it only serves to dry the skin out, which will enhance penetration. However, glycolic acid penetrates the skin just fine by itself. Lol!

    I hope that helps!

  • Nook

    Hi John! Your article is so interesting! Btw I am quite curious about the interaction between vitamin c serum (l-ascorbic acid) and glycolic acid, can I use it at the same time? Thank you in advance.
    My regimin
    1. DDF Glycolix 10% Toning Complex
    2. Skinceuticals C E Ferulic
    3. Physiogel Cream (only on the dry parts)
    4. Sunscreen
    1. Retin A 0.05%
    2. Physiogel Cream ( Basic moisturizer)
    My skin is oily and acne prone

  • @josephine

    Once again, you’re super welcome!

  • @Sânziene si Mătrăgună

    Yes it’d be best to separate the two ingredients. But like you said, you do have nothing to lose. Even if you use them together, it’ll still be much better than if you did nothing at all.

    As for the essential oils issue, I haven’t done a post that covers a LOT of them. However, I did do a post on some of them when I wrote about fragrances in skin care, and then did a case study on menthol. I’ll link them here for you:

    But yeah basically, essential oils aren’t SO bad as Paula claims them to be. I just don’t think they have any substantial place in modern skin care. Why use them, when there are so many better well-documented beneficial ingredients?

    So enjoy reading, and let me know what you think!

  • @Peach

    My readers have confronted me with that same information that you linked from Paula’s website. Here’s the thing. There is no documention saying how quickly the skin returns to its regular pH. And I’m sure it will vary from individual to individual. So when Paula says that you don’t have to wait… that’s just her opinion.

    And me recommending for you to wait is also my opinion. However, this opinion is based on speculation and of course reputable background information.

    Fact: Hydroxy acids require a low pH in order to function.
    Fact: If something has a pH of say 3 (for example the 2% BHA liquid), and you add a product or “solution” to it that has a much higher pH of say 6 (for example a moisturizer), the overall resulting pH will undoubtedly increase.
    Fact: Therefore, the pH will no longer allow the hydroxy acid to OPTIMALLY function.

    So in the end, what I’m recommending is to have the hydroxy acid work as OPTIMALLY as possible. But if you don’t have to time to wait in the morning or evening or whenever, go ahead and follow Paula’s opinion. It is completely your choice. Who knows? Maybe the reduction if efficacy from NOT waiting is quite low. Or maybe it’s quite high…

    From both personal experience and observations, when I had really bad acne (check out my blog for a brief summary: ; note that the listed skin care routine is NOT updated), when I waited the 30 or so minutes, I saw much better results. Even now, I notice much better results when I wait. But I admit, it could be the placebo effect manifesting itself. But that waiting is fine for me. I have other things to do while I wait, so why not? “Better safe than sorry.”

    I hope that makes sense. And once again, ultimately, you can do whatever you’d like! 🙂

    Now, the 3 min rule is just for when after you cleanse your face, you should not wait very long before applying your moisturizer. This is to reduce transepidermal water loss or TEWL. And I completely agree with that argument. However, with products that include active ingredients that are sensitive to pH changes like hydroxy acids and non-prescription retinoids, I still think you should wait 30 or so minutes. And if you think about it, when you apply a hydroxy acid product to your skin, that product in itself will act a bit as an occlusive layer and reduce TEWL. So the 3 min rule doesn’t apply.

    It’s all about weighing the pros against the cons; finding that perfect balance. For me, it’s much more beneficial to simply wait 30 minutes when I apply a pH sensitive product.

    Thanks for commenting!

    • Stephanie

      Hello, do you mind sharing medical references that helped you write this article please? Thanks

  • josephine

    OK, just got it. Thanks again John. You’re amazing.

  • Hi, John!

    Thank you for explaining this to me 🙂

    Well, I can create a routine in including the C+E+Ferulic in the mornings and Niacinamide in the evenings, and keep them separate, if this is to reduce all risks 🙂 Of course, I have nothing lo loose, only to gain, right?

    Thank you for the reply, looking forward to read more articles about ingredients :). Maybe even one (if there isn’t one already?) about irritants (especially essential oils, which I have stopped using on my face after finding out Paula’s Choice products). I miss fragrances (natural ones) a bit, I have to confess, so reading something about this would be very interesting. I have read an article about witch hazel (one ingredient on Paula’s no-no list), and I have already bookmarked the article about retinol… 🙂 If what I seek is somewhere on this blog, I will be happy to find and read!

  • Peach

    Thanks John! I do have one more question/commenst though.

    1) I went on Paula’s website and she states:

    How Long Do I Have to Wait Between Applying Skin-Care Products?

    What About AHA and BHA Exfoliants?
    If you’re worried about applying skin-care products right after applying an AHA (active ingredient glycolic acid) or BHA (active ingredient salicylic acid) exfoliant, don’t be. As long as the exfoliant is formulated within an effective pH range, it will work as intended, even if you apply a moisturizer or other products immediately after. The other products you apply won’t affect its performance.

    Exceptions to the Rule
    If you notice that a combination of products you’re using tends to roll or ball up when you apply one right after the other, then it’s probably best to allow the first product to dry before applying the next product in your routine. Sometimes two products’ textures just aren’t compatible—they don’t play well together—so waiting between applications is best.

    Is it possible that because the bha is pH-balanced, it will still absorb? I believe Paula’s bha is ph- balanced but I couldn’t find the pH of the cetaphil cream.

    2) my old dermatologist told me to apply my moisturizers within 3 min or drying the skin or else the moisturizers will not be as effective. So I’m not sure if waiting 30 min is best for me. In any case, I’ll switch to glycolix elite ultra lite facial moisturizer (the only downside, it’s in a jar but its only 1.6 oz so I think it’ll be used up in a couple months a lot less anyway)

    3) just saw your PCA sunscreen post…will try it. YOU’RE THE BEST!! I trust you :).

  • @Sânziene si Mătrăgună

    Well let me say first that your English is excellent, considering that it’s not your primary language!

    So I hope this answers your questions:

    Yes, I believe that if possible, to avoid all types of vitamin C when using niacinamide. However, that is just a theoretical assessment. It really just depends on how much (and these numbers will vary) each derivative actually converts to L-ascorbic acid. For example, I believe that tetrahexyldecyl ascorbate does this more so than ascorbyl glucoside. You also have to consider not just the conversion rates but also the penetration/absorption rates. And because those are all unknown, it’s just more reliable to use the two types of ingredients separately.

    As for the pH issue, what I’m saying is that the 1:1 complexation between L-ascorbic acid and niacinamide occurs at all pH values. The study just indicates that this interaction occurs most often at a pH of 3.8, hence the words “maximum value.” Therefore, if any of the vitamin C derivatives convert to L-ascorbic acid in the skin, there is a chance of interaction with niacinamide that’s also penetrated into the skin. Now, the pH value of 3.5 is only relevant to well-formulated products that already contains L-ascorbic acid, because L-ascorbic acid requires a pH of 3.5 or lower to penetrate INTO the skin. This specific pH value of 3.5 does not apply to the various vitamin C derivatives since they convert into L-ascorbic acid INSIDE the skin, which of course has it’s own internal pH. Does that make sense?

    So I reiterate, this interaction occurs all the time, it just happens the most often at a pH of 3.8. Also, a very water-resistant SPF product has no real signifcance when considering this reaction so long as it doesn’t actually contain these ingredients. It’d be best to apply these beneficial non-sunscreen ingredients before your sunscreen because while it would reduce the rate of interaction, it will also reduce the rate of penetration, which would limit any potential benefits that these ingredients provide.

    Finally, ferulic acid would not help because its stabilization effect on vitamin C is not a structural stabilization; rather a chemical one. It’s similar to how photostabiliziers like oxybenzone do not significantly reduce the rate at which octinoxate degrades avobenzone. Check out thist post for more information:

    You’re very welcome and thank you for taking the time to provide feedback!

  • Dear John,

    As a person who does not have a chemistry background, but who enjoys formulating products for myself, I find this post extremely useful! Thank you !

    Now, because I am not very confident that I fully understand the mechanism, let me ask you a more specific question.

    The latest ingredients that I want to play with in my facial care are ferulic acid, vitamin C (I have 3 forms: tetrahexyldecyl ascorbate, L-Ascorbyl Palmitate – both oil soluble, I love them in my oily serums and Sodium Ascorbyl Phosphate – water soluble, recommended pH 6.5-7) and niacinamide (recommended pH 5-7).. From what I read here, I understand that I should avoid to use in the same product niacinamide in conjunction with any form of vitamin C (even though only l-ascorbic interaction was studied).

    Now, you mention that “Now, the amount of complexation is pH dependent, with the maximum value occurring at a pH of 3.8. And since L-ascorbic acid requires a pH of 3.5 or lower in order to be protonated and absorbed into the skin, the likelihood of this interaction occurring and its consequent impacts are significant.” . Could you please clarify this statement to me? as a non English speaker, maybe I am not understanding this correctly – does this mean that a stabilized form of vitamin C (the ones I use require a higher pH) will transform in our skin to L-ascorbic, and IF the pH of the environment is 3.5 AND there’s niacinamide, the interaction and its unwanted effects will occur? Sorry if this is a dumb question , but I am trying to understand a bit deeper, with my lack of chemistry background 🙂

    So, how acidic should the environment be in order to this reaction to occur? if I create a serum (O/W) with the stabilized forms of VIT C that I have and niacinamide, keeping the pH around 6 – 6.5, with my skin having an avg pH of 5.5, how big is the risk? Also, using a very water resistent SPF product (say 45+), wouldn’t it help in mitigating this risk – when we are using derivatives of VIT C?

    Now, my second question: would Ferulic Acid be helpful in the above situation?
    My plans are to include 5% niacinamide, 1% ferulic acid, 4% tetrahexyldecyl ascorbate, 2% L-Ascorbyl Palmitate, 2% d-Alpha tocopherol in my face products (for daily use). am I hoping for too much? 🙂

    Thanks for your articles and feedback!

  • @Peach

    When I mean occlusive, I mean that specific product has a very high amount of petrolatum and other occlusive agents. But that only inhibits the penetration of products applied OVER it, not underneath. So you don’t have to worry about that.

    However, something that should be cause for concern is that you only wait 1 min before applying the Cetaphil Cream. The 2% BHA needs an appropriately low pH in order to function. So if you only wait one minute, the pH of the Cetaphil cream will undoubtedly raise the pH of the surface of the skin. Therefore, it will no longer be as efficacious. I’d recommend waiting at least 15-30 minutes between applications.

    See Catarina’s comment and my response to it to get an idea of what you can do while you wait. Hopefully it’ll give you some ideas!

  • @Sarah

    Thanks! That is such a flattering compliment!

    The concentration does matter in the sense that the more there is, the more will form a complex with L-ascorbic acid. However, if only the concentration changes, (and nothing else does such as pH, vehicle, etc…) the amount of complexation will be propertional to the concentration of niacinamide. Does that make sense?

    Waiting 30 minutes can certainly help, but we can’t know how much. It’s still ideal to separate the two ingredients, but hey, work with what you can.

    Also, if you’re wanting to use a moisturizer before the vitamin C product and before your sunscreen, you don’t have to use a niacinamide-product. Since you’re looking for “moisture,” you can just use something else that doesn’t contain anything that will degrade the vitamin C content.

    Also, the whole damp face thing has a negligible effect on absorption. Don’t forget that in most products, there is already a lot of water in the formulation. The exception of course would be nonaqueous products like completely silicone-based ones. So you don’t have to worry about this.

    I hope this helps and let me know how everything works for you.

  • @Carrie

    Lol!! You don’t HAVE to use a hydroxy acid if you don’t want to. I don’t want to complicate your routine. 🙂 I’m just too much of a perfectionist with my skin care routine; no need to follow my example!

  • @Erika

    You’re welcome. Unless I don’t see a comment, I will always respond. 🙂

    I think I’ve said this before, but for someone with an oilier skin type like you, it’ll should be fine to just apply the CRS, followed by the sunscreen.

    But anything will work, so long as there aren’t ingredients that degrade the L-ascorbic acid. Also, check out my latest post. I think I’ve found an excellent replacement for the UV Clear! By the time you see this reply, it should be published!

  • Peach

    Hmm, you mentioned that cetaphil moisturizing cream is too occlusive?

    I also have acneic, combination skin and this is what i started doing:

    Cetaphil cleanser
    Apply Paula’s 2% bha
    Wait 1 min or so
    Apply cetaphil moisturizing cream

    Would the cetaphil cream prevent the bha from penetrating the skin? Thanks John!

  • Sarah

    Hello John. Thanks for another great post. You’re my favorite contributor to FutureDerm!

    First off, thank you for bringing up this topic. For some reason, I always thought that niacinamide is a pretty neutral active that can be pair with a lot of other things. May I ask though, does it matter how concentrated the niacinamide is?

    I’m asking because I use “CeraVe Facial Moisturizing Lotion PM” after my vitamin C serum (“UNT C Clarity”, which is Taiwanese brand, glycerin based c serum with 20% L-Ascorbic acid). In the CeraVe, Niacinamide is the 4th ingredient (after purified water, glycerin, and capric triglycerides) on the list. So I assume that it is not all that concentrated.

    But for precautionary measures, should I still wait 30 minutes? And do we need to wait after applying the niacinamide based moisturizer before applying our daily sunscreen? I am using the “Pratima Neem Rose Face Sunscreen SPF 30”, which has 18.6% micronized zinc oxide.

    My other question is, is it not true that our skin is more perceptive to absorbing ingredients when it is still slightly wet/damp? If that’s the case, will waiting 30 minutes means our skin is not absorbing as much benefits from the 2nd moisturizer/serum that we’re applying?

    I know that it you suggested to others to just use a more emollient sunscreen so that we can skip the “in between” step. But I find that is a little catch 22. I’ve used a more emollient sunscreen before, and maybe it is because my skin is not that dry to begin with, I find that it takes so long for it to fully absorb into the skin. It is annoying. Whereas, I find better results when I apply an additional layer of moisturizer (like CeraVe), and then a “regular” sunscreen. I’m wonder if that’s also the case for others..

    Anyway, thanks in advance for all your help!

  • Carrie

    Thankyou so much for your response and the whole comment thread has been interesting and then you go and drop ‘hydroxy acid’ – that’s the next 1 hour gone, working out how/when i need that 🙂

  • Erika

    Thanks for your reply John 🙂

    I’ve used the Josie Maran one but it leaves my face slick– I’ve tried varying the amount I used, using it alone, using it with other products, etc. but it still leaves my face an oil mess.

    If not the Cetaphil moisturizer, which moisturizer do you recommend for my acne-prone combo skin? A while back, I saw that you used Paula Choice moisturizer and I tried their moisturizers but couldn’t find one I loved. Any other recommendations?

  • @Josephine

    Check out my post on vitamin B3, which I actually linked in the post. But here it is again:

    All the answers to your question is in that post. But I’ll give you a brief answer by saying that even in all “clinicals” that you linked, nicotinic acid or niacin has only been shown to enhance the epidermal barrier function, inhibit TEWL loss, and the like. However, unlike niacinamide, there are no studies that demonstrate its ability to reduce hyperpigmentation, be anti-inflammatory, and reduce yellowing of the skin (a result of glycation)–all of which niacinamide has been shown to do. And as I stated in that post, I didn’t say that NTA doesn’t have the same effects as NCA, I only said that it APPEARS that NTA doesn’t have the same effects as NCA due to a lack of documentation. So until more research is conducted, it’s simply just more reliable and “safe” to use niacinamide rather than nicotinic acid. Not to mention that niacinamide when applied topically, has far fewer side effects on the skin than nicotinic acid and is much more stable and inexpensive.

    Does that make sense?

    Also for more information about whether or not nicotinic acid can be considered equivalently to niacinamide when considering this complexation issue with L-ascorbic acid, make sure to read the first comment by janine, and my response to that comment. Enjoy!

  • @Eileen

    Yay!! It’s great to hear that your routine is already perfect, lol! Thanks for commenting!

  • @Kaye

    First of all, you’re very welcome.

    And you don’t have to wait much at all before cleansing and applying the CRS 10%. Just make sure to pat dry your face so that there isn’t any water on the surface of the skin. But yeah, you can apply it right after your face is dry.

    You don’t have to worry about the pH since the product itself is formulated correctly at a pH of 3.0!

  • @Tiffany Martin

    I’ve actually been planning for some time (okay like a year) to have a huge overarching “ideal routine” portal/page for all skin types on my blog. It’ll be a descriptive “template” of sorts for those with normal (not very problematic skin) skin, acne-prone skin, rosacea, mature, hyperpigmented skin, among others… I feel like I can’t cover all of that in a single post, nor perhaps even in a series of posts. Furthermore, I want this information to be accessible all the time and be a central focal point that everyone sees from a glance at the homepage. And unfortunately on FutureDerm, I can’t do that.

    Sorry to disappoint, but all I can say is that a thorough and complete guide will be up on my blog. Right now the “Ideal Routine” page is empty, but it’ll probably be the first major thing I tackle. But yeah, I realize there are so many blank spots on my blog right now. It’s just there’s such a mountain of information to obtain, read, comprehend, collate, analyze, and then write, edit, and finalize. But it’ll be up soon!

    But a quick tip is that besides vitamins C and A, as I said in the post, niacinamide and the hydroxy acids are pretty crucial. Other great antioxidants to consider include green tea, pomegranate, soy, resveratrol, coffebean, milk thistle, etc… However, products aren’t created equal so that list isn’t too helpful I know… Again, you’ll have to just wait and/or search online while you wait! 🙂

  • @janine

    I know right? Sorry everyone! When it comes to photoprotection, you are absolutely correct that L-ascorbic acid is much more important than niacinamide. As for what should go after the serum, I personally just follow with sunscreen after my antioxidant serum. I have quite oily skin so that works perfectly for me.

    But why do you feel that you have to apply a non-sunscreen product after the vitamin C serum? I don’t understand that. But I mean, anything that’s more emollient can work, so long as it doesn’t contain ingredients that can degrade the vitamin C content. And if you’re looking for additional moisture, why not use a sunscreen that’s a tad more emollient? As I’ve mentioned to other people, the Josie Maran SPF 40 is an excellent option for those with drier skin types.

    And you’re welcome! Let me know what you think about this.

  • @Catarina

    Sorry! Haha. Now, it depends whether or not the hyaluronic acid you’re using contains niacinamide or niacin, because may be a bit different when it comes to this complexation. Read janine’s first comment, and my response for further information on this topic.

    As for how you can manage the 30 minute wait time, consider something like this:

    1. When you get up in the morning, go to the bathroom and wash your face first. Then do your routine up to the Skinceuticals CE Ferulic.
    2. Then go do whatever else that’s necessary. For example, you may want to change your clothes, eat breakfast, brush your teeth, do your hair, etc…
    3. After you’ve done all that, then go back and continue with your sunscreen, makeup, etc…

    And if you take a shower in the morning, then do that first, and when you get out of the shower, go ahead and do your routine up to the Skinceuticals CE Ferulic.

    Lol, I’m just throwing out ideas for you to consider. While 30 minutes sounds like a long time, you can do a lot of other necessary everyday things as you wait. The time goes by really fast.

    I hope that makes sense!

  • @Jill

    It’d be ideal for you to use them separately, but if you must use them together, wait perhaps 30 minutes between applications. Make sure to read the other comments and my responses because quite a few of them bring up almost identical dilemmas!

  • @Erika

    Here’s the thing. As someone with combo skin, I don’t think you should be using the Cetaphil Cream because:

    1. It may be too heavy for your skin type.
    2. Because it’s quite occlusive, while it may buffer the niacinamide from reaching the L-ascorbic acid, it may consequently also also prevent the niacinamide from reaching your skin. So you wouldn’t be getting the benefits of niacinamide. I don’t think you’d want that, unless you’re using another niacinamide product at nighttime. While I think that’s redundant, it is a viable option since it sounds like you’re still misty-eyed with the UV Clear. 😉

    Waiting something like 30 minutes may decrease the amount of complexation, but I can’t give you a distinct answer. All we can do is hope for the best.

    Have you considered the Josie Maran SPF 40 moisturizer? It has a very nice lotion texture that doesn’t leave behind a white-cast. And because it is more emollient, you could remove the Cetaphil Cream in this scenario.

    Let me know what you think.

  • Josephine

    How do you know that “NTA does not exhibit the same effects as NCA” on the skin? Anything in here

    And I’m totally with everyone else — whats a beneficial product to use after our Skinceuticals CE Ferulic or Phloretin CF in the morning now that it’s not recommended to use Niacinimide (Olay) or Myristyl Nicotinate (Nia 24). My a.m. routine is CE Ferulic, Revaleskin Intense, Nia 24. Yikes……I guess.

  • Eileen

    Hi John,

    Not only was the post itself of great interest, but so were your thoughtful responses to all the questions. You had me running to check the ingredient lists on the products I routinely use. Whew! I’m doing the right thing :-). Keep these informative and helpful posts coming.

  • Kaye

    thanks for the post john!! ’twas a fun post indeed 😀

    i use CRS 10% L-ascorbic acid– it has a pH of 3.0 and is sort of an opaque, white-ish paste.

    how long do i have to wait between cleansing and applying the L-ascorbic acid?

    i use cetaphil gentle daily cleanser…..then i pat my skin dry. should i wait a couple of min before applying the L-ascorbic acid or can I apply directly after I pay my skin dry?


  • John, on reading the comments I have to say I really want you to write a post on what anti-aging products you like the most, and why. Like many people I know retinols and vit c are good ingredients but other than that I’m lost. I don’t like to make decisions based on marketing but my skin isn’t getting any younger! I hope you’ll consider it!

    Thanks for yet another awesome post, and I always learn a lot, so good work!

  • Well, John, it looks like you’ve pretty well thrown a wrench into everyone’s morning routines!
    Can i assume that the L-Ascorbic would be the more important ingredient of the two (L-Ascorbic and niacinimide) to apply in the A.M. and therefore the one product we should stick with? And if i assume correctly, what is an appropriate replacement for our niacinimide creams and lotions that would typically go on after the C serum?
    And since you obviously don’t know our individual skin types, could you make a broad recommendation(s) that would be an adequate substitue for Nia 24 and/or Olay lotions (just looking for moisture elements here, not necessarily sunscreens).
    Thanks for caring……..and i honestly mean that.

  • Catarina

    Oh no John, you have ruined my day!! No, seriously I thank you for that very important information I have read nowhere else before. I have to rethink my daily routine completely because I use c+e+ferulic in the morning, then wait 10 minutes and then apply a hyaluronic serum with niacin I love to use mornings and evenings under my cremes. I wonder how I can manage to wait 30 minutes after vitamin c in the morning, there is so little time then. But otherwise i will have to skip my beloved serum in the morning :/

  • Jill

    So, no more Skinceuticals CE Ferulic and Olay Regenerist morning routine? Thank you!

  • Erika

    What an informative post!

    Like, Kristina above, I use the Citrix CRS 10% L-Ascorbic Acid with Growth Factor and the EltaMD UV Clear SPF 46.

    Here’s my routine

    1) Apply Citrix CRS 10% L-Ascorbic Acid with Growth Factor

    2) Apply Cetaphil Moisturizing Cream.

    3) EltaMD UV Clear SPF 46

    A couple of things:

    I apply the Cetaphil Moisturizing Cream in between because because I use retinols and AHAs and salicylic acid (not all at once of course!) and my skin can get quite dry sometimes. Normally, I have acne-prone, combo skin with dry patches sometimes depending on how often I’ve used the AHAs and salicylic acid. The Cetaphil cream is non-greasy and is more of an “insurance” so that my skin doesn’t get flakey and dry.

    I looooooove EltaMD UV Clear SPF 46 DON’T TAKE IT AWAY FROM ME!! lol. I read your post on sunscreens and had tried ALL The ones you recommended except the EltaMD UV CLear. I had gone through sooooooooooooo many sunscreens I was still searching for the perfect one. And then on your recommendation, I picked up the EltaMD one and fell in love!!

    Would waiting 15 min before applying EltaMD work? I’m hoping that 15 min would not cause the L-Ascorbic Acid and Niamincide to interact 😐 or maybe the Cetaphil can buffer it??

  • @Sara

    I’d say that it’d be best to separate the two products, and use them at different times of the day.
    However, if must use both together, try to do it at nighttime and wait 15-30 minutes between applications to minimize any interactions.

    Try reading my responses to the other people above. Maybe you’ll get some new ideas of what you can do.

    I hope that helps and as always, I’m here if you have more questions. 😉

  • @Kristina Katai

    Dang. I really hate to correct your routine because all the products are excellent alone! Well, except the Olay Night Cream since it’s packaged in a jar.

    So let me ask you, why do you apply the Olay Night Cream before the UV Clear and after the 10% AA product? If it’s because your skin is dry and you need more emollience, we can perhaps bypass any chances of interaction by removing the Olay Night Cream, and replacing the UV Clear with a more emollient sunscreen. Any of the ones I recommended for drier skin types in my sunscreen post:, will be fine. The Clinique SPF 25, EltaMD SPF 30, PCA Skin SPF 30, are all fantastic choices. Furthermore, I forgot to include another excellent sunscreen for drier skin types: the Josie Maran SPF 40. I can’t believe I forgot to include it! Haha.

    But what to do with the Olay Night Cream and EltaMD UV Clear that you already have? I’d say to not repurchase either, and use the Olay at nighttime until it’s all gone. As for the EltaMD UV Clear, perhaps consider swapping it or exchanging it? Ultimately, you can still finish it with your current routine because while there MIGHT be a bit of hydrogen peroxide generation, the amount shouldn’t be too high since you’re factoring in the sunscreen aspect; a lot of the UV rays should be absorbed and scattered by the zinc oxide and octinoxate contents of the UV Clear. The studies I linked above did not include any UV filters.

    Does that all make sense? I know it’s a bit convoluted. Let me know if you have any further questions!

  • @Carrie

    Your routine is fine! You’ve separated the L-ascorbic acid from the niacinamide, so the chances of any interactions occurring are negligible.

    However, can I note that you may want to switch to another Olay product, just because that one you’re using is packaged in a jar. While niacinamide is quite stable, it will still degrade over time and will do so more quickly when it’s constantly exposed to air. Not to mention that the other beneficial ingredients present WILL degrade much more quickly in the presence of air. 🙁

    As I mentioned in the vitamin B3 post:, the Olay Total Effects 7-in-1 Moisturizer Plus Mature Therapy is a great option for those with drier skin types.

    I hope that helps and thanks for commenting!

    Oh, and thanks for your interest in our retinol product. It may be quite drying due to the alcohol content, but if you can make it work, it’s hugely beneficial!

  • @janine

    The studies only refer about niacinamide. However, in the previous post on vitamin B3, we did learn that NTA converts to NCA when taken orally. Whether or not that occurs in the skin is unknown. However, that may be unlikely since NTA does not exhibit the same effects as NCA on the skin. And this could be because it doesn’t actually convert to NCA in the skin, and/or that there aren’t enough studies done to elucidate this matter.

    So I’d say keep doing what you’re doing since the chances of any interaction occurring are low. This is because:

    1. The form present in the Nia24 is myristyl nicotinate, which has to convert to free nicotinic acid, before converting (if it does at all) to niacinamide. The rates of conversion are most likely quite low.
    2. It is unknown whether or not nicotinic acid itself (without converting to niacinamide) can form a complex with L-ascorbic acid. However, given its structural similarities to both niacinamide and tryptophan, there may be an interaction. Keep in mind that this is pure speculation.
    3. But ultimately, because you’re not using this combination in the presence of UV light (daytime), you’re not damaging your skin in any way. You may be just theoretically not “helping” it as much as if you were to use both products separately.

    Does that make sense? I apologize that I can’t give you a more clear answer; no studies that I know of are directly linked to this subject. I hope I didn’t confuse you more. 🙂

  • @AwwRITE!

    You’re very welcome.

  • Sara

    How about skinceuticals cf w/phloretin gel and a niacinamide cream on top of it? Thank you so much for the posts.!

  • Kristina Katai


    My morning routine is:

    Cleanse with Cetaphil Gentle Skin Cleanser

    Apply Citrix CRS 10% L-Ascorbic Acid with Growth Factor (

    Apply Olay Regenerist Night Recovery Cream…which has niacinamide!

    Apply EltaMD UV Clear SPF 46…which also has niacinamide!

    Any advice John? I just started this entire routine a few days ago so I haven’t been using it long enough to see any results. Should I swamp out some products?

  • Carrie

    Would it be safe to use them for am/pm routines, this is my current routine (after some tidbits on this site).

    Cosmetic Skin Solutions CSS CE Ferulic
    Boots Protect and perfect
    Khiels Super Fluid UV Defense SPF 50+

    Cosmetic Skin Solutions Retinol 0.5
    wait 1 hour then apply Olay Pro X Hydra Firming cream.

    I’m also looking into replacing the boots&khiels with something new and trying your new retinol once mine runs out.


  • Would the same apply to nicotonic acid?
    I currently use CE Ferulic, wait 15 minutes, then apply NIA 24 Skin Strengthening Complex. Should i rethink this combination?

  • AwwRITE!


  • @AwwRITE!

    I’m not going to say to stop using these two products, since they’re both very good alone. And together, the interaction should be very minimal since:

    1. The pH is not very low
    2. Ascorbyl glucoside (the derivative present in the Algenist) is probably one of the weakest and least converting-to-L-ascorbic-acid forms available on the market.

    And it does help to wait between applications, though it is unknown by how much. In your case, I’d say just keep doing what you’re doing! 🙂

  • AwwRITE!

    So does that mean I need to stop using this product with this product ?
    Does it help if I wait at all between applying one and then the other?

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