At a low PH, niacinamide and L-ascorbic acid can turn aqueous solutions yellow.
These days, while it’s (more) common knowledge that acidic compounds like hydroxy acids should not be used with retinol, the interaction between two other prominent and well-studied compounds: niacinamide and L-ascorbic acid, 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!
I’m surprised that this interaction hasn’t gotten more press! Therefore, let’s dive right in.
What Exactly Is This interaction?
L-ascorbic acid or 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. 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.
So don’t mix the two compounds!
Does This Occur with Vitamin C Derivatives?
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.
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.
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!
About Author
John Su describes himself as eccentric—you might find him having a conversation with himself. He’s a stickler for accuracy, so you might find him correcting one thing or another! His goal is to answer questions and provide unbiased, meaningful, and insightful information when it comes to skin care. His underlying motivations stem from a need to inform people who have doubts, questions, or even prayers for solutions to their problems. He has his own skin care blog, The Triple Helixian.
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AwwRITE!
So does that mean I need to stop using this product http://www.algenist.com/products/regenerative-antiaging-lotion with this product http://www.eltamd.com/ProductDetail.aspx?p=18 ?
Does it help if I wait at all between applying one and then the other?
John Su
@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!
Thanks!!
janine
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?
Carrie
Would it be safe to use them for am/pm routines, this is my current routine (after some tidbits on this site).
AM:
Cosmetic Skin Solutions CSS CE Ferulic
CSS HYDRA B5 GEL
Boots Protect and perfect
Khiels Super Fluid UV Defense SPF 50+
PM
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.
Thanks
Carrie
Kristina Katai
Darnit!!
My morning routine is:
Cleanse with Cetaphil Gentle Skin Cleanser
Apply Citrix CRS 10% L-Ascorbic Acid with Growth Factor (http://www.dermstore.com/product_Cell+Rejuvenation+Serum+10+Percent+With+Growth+Factor_3909.htm)
Apply Olay Regenerist Night Recovery Cream…which has niacinamide!
Apply EltaMD UV Clear SPF 46…which also has niacinamide!
(http://www.eltamd.com/ProductDetail.aspx?p=18)
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?
Sara
How about skinceuticals cf w/phloretin gel and a niacinamide cream on top of it? Thank you so much for the posts.!
John Su
@AwwRITE!
You’re very welcome.
John Su
@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.
John Su
@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: http://www.futurederm.com/2012/09/27/spotlight-on-vitamin-b3-niacinamide-and-nicotinic-acid/, 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!
John Su
@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: http://www.futurederm.com/2012/09/13/are-inorganic-sunscreens-better-than-organic-ones-part-v-conclusion-and-product-recommendations/, 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!
John Su
@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.
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??
Jill
So, no more Skinceuticals CE Ferulic and Olay Regenerist morning routine? Thank you!
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 :/
janine
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.
Tiffany Martin
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!
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?
thanks!!!
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.
Josephine
How do you know that “NTA does not exhibit the same effects as NCA” on the skin? Anything in here http://www.nia24.com/science/clinicals.cfm
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.
John Su
@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.
John Su
@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!
John Su
@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!
John Su
@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.
John Su
@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!
John Su
@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!
John Su
@Eileen
Yay!! It’s great to hear that your routine is already perfect, lol! Thanks for commenting!
John Su
@Josephine
Check out my post on vitamin B3, which I actually linked in the post. But here it is again:
http://www.futurederm.com/2012/09/27/spotlight-on-vitamin-b3-niacinamide-and-nicotinic-acid/
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!
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?
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
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!
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!
John Su
@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!
John Su
@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!
John Su
@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.
John Su
@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!
Sânziene si Mătrăgună
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!
John Su
@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:
http://www.futurederm.com/2012/10/12/how-does-octinoxate-degrade-avobenzone/
You’re very welcome and thank you for taking the time to provide feedback!
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.
http://www.cosmeticscop.com/how-long-do-i-have-to-wait-between-applying-skin-care-products.aspx
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
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!
josephine
OK, just got it. Thanks again John. You’re amazing.
John Su
@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: http://thetriplehelixian.com/my-story-and-routine/ ; 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!
John Su
@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:
http://www.futurederm.com/2012/05/25/is-fragrance-in-skin-care-good-or-bad/
http://www.futurederm.com/2012/06/07/spotlight-on-menthol-a-fascinating-look-at-a-mysterious-ingredient/
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!
John Su
@josephine
Once again, you’re super welcome!
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
AM
1. DDF Glycolix 10% Toning Complex
2. Skinceuticals C E Ferulic
3. Physiogel Cream (only on the dry parts)
4. Sunscreen
PM
1. Retin A 0.05%
2. Physiogel Cream ( Basic moisturizer)
My skin is oily and acne prone
John Su
@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!
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: http://www.theherbarie.com/Niacinamide-USP-Vitamin-B3.html) 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!
France
PS
Your idea to create an “ideal routine” portal/page for all skin types on your blog sound like pure genius to me!
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!
http://www.drbaileyskincare.com/blog/why-the-right-skin-care-for-your-skin-type-matters/
^Her statement about half life is in the comments section
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. acne.org 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. acne.org cleanser
2. CRS 10% L-Ascorbic Acid
3. Glycolix Elite Ultra Lite Facial Cream
4. PCA Skin Weightless Sunscreen
NIGHT:
1. acne.org 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?
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:
http://www.drbaileyskincare.com/blog/whats-the-best-anti-oxidant-skin-care-product/
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!!!