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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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.
John Su
@Ann
Thanks so much! I’m super glad to have you. And congrats on being the first comment on the second page.
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…
John Su
@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!
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
Great news, b/c I just ordered the PC toner! Thanks for putting my mind at ease!
John Su
@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: http://www.ncbi.nlm.nih.gov/pubmed/18636178 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?
John Su
@Joni
Sure no problem!
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!
John Su
@Erik
Thank you good, sir!
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?
John Su
@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
Thanks for the answer!
John Su
@Marie
Sure, you’re welcome!
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.
John Su
@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: http://www.futurederm.com/2012/09/27/spotlight-on-vitamin-b3-niacinamide-and-nicotinic-acid/
Sam
@John
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
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!
John Su
@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?
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
@John
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!
John Su
@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!
John Su
@Sam
Yay! I understand.
And using niacinamide after your retinol is a very wise decision.
Chris
John,
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?
John Su
@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.
Nikita
John,
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!
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!!
John Su
@Nikita
I actually wrote a follow-up post in regards to the use of niacinamide and acidic ingredients like hydroxy acids here: http://www.futurederm.com/2013/01/24/should-niacinamide-and-acidic-ingredients-be-used-together/
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
Thanks John! I guess I’ll just try to find another way to incorporate niacinamide.
John Su
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: http://thetriplehelixian.com/2013/05/19/massive-personal-changes-mini-giveaway-and-the-publishing-schedule-for-the-race-to-100-blog-completion/
Those posts should hopefully answer any and all questions you have about your skin care routine.
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
John Su
@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: http://thetriplehelixian.com/2013/05/19/massive-personal-changes-mini-giveaway-and-the-publishing-schedule-for-the-race-to-100-blog-completion/ 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.