Can You Really Use Retinoids with AHA, BHA, and L-Ascorbic Acid or Not?

For years, we have received this question here at FutureDerm.com.  And it certainly is a great one:  Of the leading skin care ingredients on the market, retinoids, AHAs, BHAs, and L-ascorbic acid are all industry leaders in both prevalence and efficacy.

As renowned dermatologist Dr. Leslie Baumann, M.D., revealed to us in an exclusive interview earlier this year, “You have to also be careful not to use a product that has ingredients that can render the active ingredient useless.  Vitamin C (L – Ascorbic Acid), Glycolic (AHA), and salicylic acid and kojic acid can break down retinol and retinoids.” Retinoids and acids simply function better when applied separately.  This is because of a two-part enzymatic oxidation process in which retinol is converted within your skin to become active:  First to retinaldehyde, then to all-trans retinoic acid.  Retinol oxidation is optimized at a neutral pH (Nature).  This is because the enzymes responsible for this oxidation, called retinol and retinal dehydrogenases (DHs), are most active at this pH.  So don’t mix retinoids and acids.

So if you mix retinol with acidic products, there will be suboptimal conversion of retinol to its active form within the skin.  Will you still get some effects?  Sure.  But for best effects, use acidic products during the day, and retinol at night.  See below for more.

Aren’t There Multiple Pathways of Conversion?

Retinoids – not retinol – can be activated via a number of pathways.  It’s easy to see how this can get confusing. However, as I learned in medical school, no matter which pathway all-trans retinoic acid may undertake, retinol must be converted to retinaldehyde and then retinoic acid within keratinocytes (skin cells) in order to be active (Journal of Biological Chemistry).

The enzymes responsible for the oxidation process – dehydrogenases (DHs) – underlie every pathway of retinol activation within the skin.  Don’t be fooled by irrelevant citations:  Two types of dehydrogenases must convert retinol to retinylaldehyde and then to all-trans retinoic acid within the skin to be activated.   This is optimized at a neutral pH (Nature). So for maximal effects for your skin (maximal effects occurring with optimal conversion of retinol to its active form), apply retinol and acidic products at different times of the day.

Retinoids and Vitamin C are NOT Network Antioxidants

Skin care science can be complicated.  And so can antioxidants.  There are hundreds of naturally-occurring antioxidants.  However, it is most beneficial to use antioxidants that fight off free radicals in the same pathways together.  Why?  Just as it’s more effective for policemen to travel in packs of two (or more), antioxidants in the same pathway can enhance the power of each other.  Except instead of backup in firearms, network antioxidants work synergistically to donate electrons to depleted others.  Retinoids and L-ascorbic acid are both antioxidants, but they do not exist in the same pathways.  So when retinol loses its electrons in its pathways, L-ascorbic acid cannot regenerate it, and vice versa.  In truth, L-ascorbic acid has been found to regenerate only vitamin E, glutathione, coenzyme Q10, and alpha lipoic acid (Packer et. al., 1999; Cosmetic Dermatology, 2010).

So these ingredients do not fight off free radicals together as beautifully as vitamin C and E do.  They work together, but each ingredient will function suboptimally.

If Nothing Else, Skin Will Be Irritated!

For the sake of argument, let’s say that you don’t care about optimal results from your skin care.  Good enough is good enough.

Even so, the pH of your skin care products matter.  “Changes in the pH are reported to play a role in the pathogenesis of skin diseases like irritant contact dermatitis, atopic dermatitis, ichthyosis, acne vulgaris and Candida albicans infections” (Skin Pharmacology and Physiology, 2006).

What’s more, skin care products do have significant effects on each other.   Acidic solutions are associated with increased skin exfoliation (and subsequent sensitivity), so it’s not a great idea to use potent products after sloughing your skin.  (If you don’t believe me, make the mistake of applying a concentrated 1.0% retinol treatment after a 10% glycolic acid peel.  You will feel the burn!)  On the other hand, basic products increase skin swelling and rigidity, because they disrupt the skin’s acid mantle (Dermatologic Therapy, 2004).

Unless you’re the type of person who diligently waits 30+ minutes between applying each product, chances are, the pH of the skin is still temporarily lowered by the application of the acidic product. We don’t mean to suggest products permanently change the pH of your skin, but after the initial application, you are slightly altering the pH of the skin, albeit temporarily. This alteration is what causes a physical effect or change.  For instance, let’s talk about salicyclic acid.  According to a 2009 study in the International Journal of Cosmetic Science, 1% salicyclic acid introduced to skin at pH 6.50 produced absolutely no stinging or redness sensation.  On the other hand, 1% salicyclic acid introduced at the acidic pH of 3.12 produced redness and stinging. And this is just one example.

Keep Retinoids for Night!

Retinol works because it is converted to all-trans retinoic acid in the skin.  In turn, all-trans retinoic acid makes the skin photosensitive (British Journal of Dermatology).  It has been suggested retinol is anywhere from 5% (Clinics in Dermatology, 2001) to 10% as potent as all-trans retinoic acid (Journal of Investigative Dermatology, 1997).  Prescription all-trans retinoic acid at 0.025-0.040% issues warnings all over the bottle to wear sunscreen and avoid daytime use.  So why would you apply 0.25-1.0% retinol, not wear sunscreen, and use it in the daytime? It makes no sense. And even if you do apply sunscreen, there is absolutely no additional benefit to using retinol at daytime compared to a nighttime application of retinol. There are only potential drawbacks. And with the appropriate retinol strength, vehicle, and complementary skin care routine, daily nighttime applications of a retinol product will be potent enough for any skin type!

Bottom Line

If you’re the type of person for whom “good enough” is fine in skin care, then go ahead, keep applying retinoids and acids together.  However, for the maximum result from your acidic and retinol products, apply them separately.  The class of enzymes necessary for retinol activation - dehydrogenases – function best at a more neutral pH. In addition, acidic products increase skin’s exfoliation (and hence sensitivity).  So it’s best for both form and function to apply these products separately.  Trust me – I’d love to be able to sell our FutureDerm Time-Release Retinol 0.5 and upcoming FutureDerm Vitamin CE Serum for use together.  But I would never want to tell our readers something that could be less than beneficial for their skin, and research shows not only to use these separately for best results, but also that retinoids are best for nighttime use.

***Please note that this concept discused does NOT occur between prescription retinoids and acidic products; only retinol and retinal(dehyde) are affected.

Related Posts

  • 82
    If you know me, you know that there are just a few things that I am super passionate about: Journals. Bookstores. Shih-Poo puppies. Black coffee. Spicy food. And in the realm of skin care, I similarly believe in loving few but loving hard, with retinoids, sunscreen, AHAs, vitamin C, vitamin E, green tea, and peptides…
  • 76
    I recently received an email from a reader stating that Paula Begoun says you can use a retinoid with an acidic product, and wanting to know why I disagree. As longtime FutureDerm fans know, I've battled it out with Paula before over alcohol use in skin care (my post, her response). I have the utmost respect for Paula;…
  • 71
    Dear Nicki, The article I'd like to ask a question about is "Can You Really Use Retinoids with AHA, BHA, and L-Ascorbic Acid or Not?" The article you referenced (Gao & Simon, 2005) regarding the conversion of retinol to retinoic acid states in the abstract that “The hydrolysis reaction is greater at neutral pH, whereas…

by Nicki Zevola

31 thoughts on “Can You Really Use Retinoids with AHA, BHA, and L-Ascorbic Acid or Not?

  1. Matheus F. says:

    I’m brazilian, and luckly I do exactly what you suggest, but instead of retinol I use tretinoin, and Age+ Blemish Defense under a potente zinc oxide based japanese sunscreen, during the day.
    I’m not sure you know, but here, in Brazil, we can buy tretinoin for $15, without prescription. And a good product.
    Retinol products, instead, are more expensive, that are Redemic R that cost more than $50, and Roc products that are expensive too.
    Well, it’s such a good think, yeah?

    But do you know why tretinoin is so expensive in USA and so cheap in Brazil?

  2. caitie says:

    Thanks for this – what if you use a AHA/BHA face wash before applying a retinol product? Would that be strong enough to downgrade the effectiveness of the retinol product? So complicated! Lucky we have you guys to explain it to us! :)

  3. jeff says:

    i talked live to somone on paula begouns site…they insisted you could use thier BHA and Retinol products at the same time, layered…how could that be??

  4. Nicki says:

    Hi @Caitie – In general, I avoid using retinoids and acids together in all treatment products for maximal efficacy and minimized irritation. However, using an AHA cleanser will give you some exfoliating action and not change the pH of the retinoid you apply after much, if at all. So the question becomes, is your skin sensitive? Do you feel irritation using both? I would not recommend it but it can be done. Hope this helps!

  5. Nicki says:

    Hi @Jeff – A BHA cleanser followed by a moisturizer will still work, but for maximum efficacy, you want to use these separately. This is due not only to the slight modification in pH from using an acidic cleanser, but also the fact that acidic cleansers are exfoliating and can make other topical ingredients like retinoids seem more harsh and irritating. If your skin is sensitive, avoid using both together.

    Truth be told, you will get effects using them together. But, you will get more from each ingredient using them separately, especially if your skin is sensitive. Hope this helps!

  6. Lucas says:

    I’ve also missed your blog posts, Nicki!

    This is very relevant information for those who want to get maximum results from their skin care routine.
    You should make it clear though, that the pH concern doesn’t apply to prescription retinoids, since it is bound to be some confusion about that.

    Best!

  7. jeff says:

    yes, thank you, im just surprised at paula begoun who should now better than saying using acidic products with a retinil at the same time

  8. Lucas says:

    What about the skin’s natural pH, wouldn’t it also make the conversion of retinol less effective, considering the skin’s pH is acidic? Following the thought process that retinol is better converted at neutral pH, it seems the skin’s pH wouldn’t allow for optimal conversion.

  9. HB says:

    First of all…I love that you add ‘the bottom line’ to all your articles. When I’m in a rush, I can scroll down and get the gyst of it. Can you think about doing an article on beauty pillows (satin/odd-shaped pillows that are meant to prevent wrinkles…do these work)? I have another question: my esthetician told me it was important to use a pH balancing spray before applying serums or else my skin would not be able to absorb the ingredients effectively. Is there any truth to that? She recommended this one: http://www.methodephysiodermie.com/pr_toner.html

    I’m wondering if I’m just wasting money by investing in a pH spray….thoughts?

  10. John Su says:

    @Bung

    I believe you’ve asked me this question before multiple times lol! And the answer is no, since prescription retinoids don’t need to convert to anything to function on the skin.

  11. John Su says:

    @Lucas

    You’re right about the prescription retinoids; it is a commonly confused issue. I’ll be sure to edit the article and add that notation.

    As for the skin’s pH isue, the enzymes responsible for the conversion process have a pH range of optimal efficacy; it’s not an exact number. In the post, it’s stated that the maximal conversion occurs at a MORE neutral pH. That doesn’t mean a pH of 7. Furthermore, in the link to the actual enymatic process, which was a post written a few months ago, it was indicated that the skin’s pH is not the same in all the layers of the skin. It was suggested that because the optimal pH ranges of each subsequent enzyme became steadily more neutral and that they occur more deeply in the skin, that the skin’s pH lessened in acidity in relation to “depth.” So no, the skin’s pH is perfectly optimized for conversion.

    I’m pretty sure you’ve asked this question too on my blog… but I’d have to go back and check.

  12. John Su says:

    @HB

    A pH “spray” is an antiquated notion. They were necessary befoer because most cleansers were very alkaline, and a pH-correct toner was necessary to realign the skin’s pH. These days however, most water-soluble cleansers are already properly formulated in terms of pH. So a toner’s main purpose is not to correct pH.

    You can also forget about the whole absorption thing. Fun fact: In fact, an alkaline-pH will actually allow more penetration since an alkaline pH does not allow the skin to function properly, which of course we don’t want. And this weakened or damaged epidermal barier will allow more compounds to penetrate. Remember, the main purpose of the skin is to prevent external factors from being absorbed systemically.

    Now, the link you gave me doesn’t provide an ingredients list of the product, so I can’t evaluate its integrity or value. It’s probably not worth the money though, but who knows.

    I hope that makes sense.

  13. Laura D. says:

    I use the Juice Beauty Peel Green Apple Peel for Sensitive Skin, which has AHA in it, once a week at night and wait a day or two before applying my FutureDerm Retinol to avoid irritation. So far it’s working pretty well! Can’t wait to try the CE serum :)

  14. Lucas says:

    Hi, John,

    I think I asked about the prescription retinoids (if the pH was a concern for them), since I only know it isn’t because you explained it to me!
    But I just thought about the skin’s natural pH question, and what you said makes sense. So the retinol would only be converted deeper in the skin, where the pH might actually be lower?

    Thanks!

  15. John Su says:

    @Lucas

    It’s not that retinol will ONLY be converted at a certain depth. It’s more that the conversion process may be compartmentalized, and generally speaking, the conversions closer to tretinoin on the metabolic pathway do occur more frequently at deeper parts of the skin.

    Does that make sense?

    Happy Thanksgiving!

  16. Trae says:

    Thanks for the wonderful article, Nicki and John ^_^

    I saw another commenter mention using an AHA cleanser with a retinol product at night, and this is what I’m currently doing myself, as Leslie Baumann *seemed* to okay this sort of combo (specifically AHA cleansers with retinol, but not leave-on products) in ‘Skin Type Solutions’, and I don’t usually experience irritation from this as long as I’m careful. In your opinion, though, is there still a chance of interaction between these products, even though the acidic product is rinsed from the face ?

    In the past, I alternated nights with leave-on AHAs and retinol, and that worked very well, actually. I would even place my ascorbic acid serum on top of the AHA on ‘acid skincare nights’, and the L-AA actually seemed to work a lot better at improving skintone when used that way than it does used in the morning, as I apply it now…also saved me a lot of time and occasional irritation in the morning from applying after shaving. I sometimes think about switching back to such a schedule since it was *so* much more convenient for me….

    Anyhow, thanks again for the article, guys: these are really helpful for us who like to use multiple actives (without them fighting with eachother LOL) ! ^_^

  17. John Su says:

    @Trae

    No, I’m okay with using hydroxy acid cleansers and retinol products since the former don’t stay on the skin for too long. However, they will still affect the pH of the skin (temporarily). Furthermore, because they aren’t on the skin for very long, their benefits won’t be as enhanced, which is why I always recommend a leave-on hydroxy product and a regular cleanser. I mean, why go halfway by using JUST a hydroxy acid cleanser?

    Does that make sense?

    And using hydroxy acids with L-ascorbic acid is a very appropriate move! As long as you don’t experience too much irritation, keep doing it!

    Finally, multiple actives are necessary, and it is certainly confusing to use everything together effectively. That’s why I hope the Ideal Routine page will “illuminate the way!”

  18. Trae says:

    @John

    Thanks for the reply ! And I completely understand and agree that one gets more ‘bang for the buck’ with leave-on products. I’ve always wondered if the reason AHA cleansers generally tend to have a higher load factor of glycolic acid when compared to their leave-on cousins (usual ranges I see for cleansers is 12 to 20 % GA vs 5 to 15 % for leave-on) is because the manufacturers know that the contact time will be so short that they need to get a lot of acid in contact with the skin very quickly LOL.

    The only reason I switched away from leave-on AHAs to cleansers is that some of the derms I read recommend using a retinol product every night and the AHA cleansers don’t interfere with that but still allow some chemical exfoliating action on the skin, but truth be told, my skin is on the sensitive side, and a lot of the time I actually can’t use retinol every night anyway, so going back to alternate nights might really be the better option for me overall and would allow me to use a leave-on AHA product again (I still have some under my sink -_^).

    Glad to hear that you like the idea of using L-AA with AHAs — that’s how I used to set up my regimen when I alternated nights: L-AA with glycolic acid on night one and retinol with GHK-Cu on night two. The wait time with L-AA in the morning, where I have it now, is pretty inconvenient for me, whereas wait times with acids are no problem at night, so that’s another reason to go back to an alternate night regimen.

    Thanks again for the reply — I think an ‘alternate-night regimen with leave-on AHAs’ is definitely in my immediate future -_^

  19. Stacey says:

    This site is awesome! It’s the first place I’ve actually felt like I’m getting honest, scientifically sound skincare advice! I’m so jazzed! I’ve been hunting down retin products and I think based on your stellar blog I’m going to give yours a try! I have a question regarding moisturizer though! What would you recommend for a nice rich moisturizer after a retin a Creme? I am interested in trying something with copper peptides since I want to use a C serum in the morning and cannot combine the two. Correct me if I’m wrong but copper peptides are not bad with retins are they? I shelled out 90 bucks at sephora today hoping to find a good moisturizer to use over a c-serum and based on reviews I bought the ole henriksen “express the truth” moisturizer. I’m a little worried now since it says it has ester-c and some copper thingy(not sure if its a peptide! Also it has other non copper peptides – this link has the ingredients http://www.sephora.com/product/productDetail.jsp?skuId=966309&productId=P133502

    Will those ingredients clash with either a c-serum or a retinoid? Specifically the retinoid on sale at future derm. I had initially planned o use the c-serum in the morning with the ole moisturizer since I figured that since it has a form if vit C in it and a non peptide copper that it would be fine (not sure this is true now). Can I use this OH product over the retinoid? What would you recommend (is a copper peptide formula on a retinoid ok?) I use?

    Also – in a previous post did you say glycolic (or other AHA’s) could be used with a vitamin C serum?

    Thanks! I love this site sooooo much!

  20. Stacey says:

    Will your upcoming C+E serum be at all similar to the skinceudicals, timeless, etc ones you mentioned in another blog post with the inclusion on all three vitamin C forms- l-ascorbic, MAP and “that other one I can’t remember!”? I’m really anxious to try it! Water or silicon based? Sorry, I’m the kid who always shook the presents under the tree! Gotta know! Ah! Love this place!

  21. John Su says:

    @Stacey

    Let me clarify that Retin-A is a drug name, not the name of the chemical compound, which is actually tretinion, a prescription-only retinoid (at least in the United States). It’s different from retinol, as retinol is a precursor to tretinoin. So be sure not to confuse the two.

    And yes, you can use copper peptides products with retinol products (and tretinoin if you have a prescription for it). Howeve truth be told–pun intended, I wouldn’t recommend the Ole Truth product. :(

    One, it’s packaged in a jar, which will accelerate the degradation process of the product. Two, the form of vitamin C, calcium ascorbate, has very little research behind it. Three, the pH is not low enough to allow it to convert to L-ascorbic acid anyways. Finally, I highly doubt this contains 10% of vitamin C content.

    Despite those negatives however, this product can still be used with our retinol product because it doesn’t have a very low pH. This article only talks about not using retinol products with properly-formulated and therefore, acidic L-ascorbic acid products (pH < 3.5).

    And yes, glycolic acid and other hydroxy acids can certainly be used with a vitamin C product!

  22. Loop says:

    I have badly burnt my skin with Retinol creams. This was due to wearing it in the daytime, with SPF and scuba diving to 30 meters. Now my skin is sensitive to almost all products and is a continuous battle to maintain. I believe the acid mantle is damaged beyond repair leaving a sensitivity to any change in pH. Have you any thoughts?

  23. Kim says:

    Thank you John and Nicki for all of this wonderful information. I just want to clarify…is it OK to use an AHA topical lotion, then after a half hour or so apply tretinoin? Does this not deactivate the tretinoin. Thanks so much.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>