How to Exfoliate: Multitasking with Chemical Exfoliants

Chemical exfoliation guide

The most recent episode of the Snailcast was all about acids and how to exfoliate safely and effectively, and I’m super bummed because I wasn’t able to join thanks to moving hassles. But the topic got me thinking about acids and reminded me that I’ve been doing mine in a different way than I used to. A more efficient way, and one that substantially reduces the risk of overexfoliation and irritation. If you want to hear about it, read on!

Affiliate links in this post are marked with an asterisk(*).

Chemical exfoliation pros and cons

If you’re unfamiliar with alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs), I highly recommend that you research how to exfoliate with them before moving ahead with this or any other method of chemical exfoliation. Actives are serious business. Episode 17 of the Snailcast would be a great place to start. The episode notes also link to some fantastic resources for learning about actives.

Vitamin C, AHA, BHA, and spot treatmentEven if you’ve been using chemical exfoliants for a while, sometimes it’s good to take a step back and really think about what they do and whether you’re using them in the best possible way for your skin. So let’s start with a quick rundown of the main pros and cons of the most common acids.

  • L-ascorbic acid (vitamin C) Pros: The “gold standard for vitamin C” according to The Beauty Brains, L-AA can increase collagen production, reduce hyperpigmentation, and provide antioxidant protection against sun damage and environmental stress. Cons: Effectively formulated vitamin C serums can be irritating due to their low pH. They can also contribute to overexfoliation if used with other exfoliants.
  • Alpha hydroxy acid (AHA) ProsCan reduce active acne, promote smoother skin texture, and brighten skin by exfoliating the upper layers of skin. ConsAHAs are a very common culprit of overexfoliation because of how effective they can be at…exfoliating. The upper layers of your skin need some dead cells to maintain the integrity of your barrier!
  • Beta hydroxy acid (BHA) Pros: Oil soluble and therefore able to penetrate more deeply into pores, BHAs are great at minimizing the appearance of pores by clearing out old sebum and dead skin collected in the pore (think of those plugs as your face’s dust bunnies). Cons: In addition to increasing the risk of overexfoliation, BHAs can be quite drying to skin.

The chemical exfoliation conundrum

As you can see from the list above, L-AA vitamin C, AHAs, and BHAs all offer compelling benefits. It can be extremely tempting to decide that you want them all.

Vitamin C serum, AHA, BHA, and spot treatment
I caught them all.

But as you can also see from the list above, each type of active also comes with drawbacks, and if you use all the actives, well, you open yourself up to suffering all the consequences. Overexfoliation is no joke, people. It can significantly worsen problems like fine lines, wrinkles, dryness, sensitivity, and acne.

Even if your skin is tough enough to handle all the actives all at once, there’s still another problem: the wait time question.

Papa Recipe AHA gel
My stinky Papa Recipe AHA is at a pH of 4, for example.

In many skincare enthusiast circles, which really are a thing because the Internet is amazing, it’s considered best practices to wait a certain amount of time (15-25 minutes generally) after each active. This is not only to allow the product to dry down and penetrate before applying additional products, but also to allow these pH-dependent actives to remain undisturbed at their optimal pH levels for as long as possible.

The necessity of wait times hasn’t been conclusively proven, though. Even within the Snail Unit, we’re divided on the topic. Tracy and Snow do wait times. Chel doesn’t. I’m undecided. I’ve waited after each active step for as long as 30 minutes for months and as little as 5 minutes, also for months, all without being sure of the more effective way. Presently, I wait when I have the time and patience but don’t let myself get too anxious or guilty when I don’t. If you believe in the importance of wait times, then using all the actives means that you’ll be spending a damn long time just waiting on your acids to neutralize! And even if you don’t and just want to wait until they’re fully dry, say 5-10 minutes, you’re still spending a pretty decent amount of time just waiting.

If you think about it, you probably don’t need to suffer through that after all!

Get the most from your acids in the shortest amount of time and with the least risk of irritation

Now we come to it. My ONE WEIRD TRICK!!!! that I adopted recently and without much thought and that is working out so well for me that I doubt I’ll ever go back to the old way again.

It’s really not that weird or groundbreaking, actually. But judging from the number of questions I’ve seen here and there about layering actives, dealing with wait times, avoiding overexfoliation from using a full acids regimen, and how to exfoliate in general, it may be a solution overlooked by more people than just me.

Cosrx BHA Blackhead Power Liquid and Naturally Embo cotton puffs
Sorry for dragging this out, but I enjoy artificial suspense.

The idea came to me when I remembered a conversation I had with Tracy a while ago about spot treating active acne blemishes with a strong AHA. That’s a great idea–and there’s no reason on earth why you can’t extend that to all the rest of your actives regimen! Instead of layering each step all over your face, dramatically increasing your risk of irritation and overexfoliation as well as your time spent waiting for shit to dry, just combine some or all of your actives into one step by using each only on the areas that actually need it.

Here’s how it typically works out for me:

  • L-AA: When it comes to using actives full-face or as a spot treatment, I think L-AA is the best candidate for the full face approach, since it has some great antioxidant and anti-aging properties. But I use OST C20 Original Pure Vitamin C Serum right now, and C20 really isn’t the most effectively formulated vitamin C serum for long-term anti-aging purposes, as my personal snailguru Chel explained. C20 brightens exceptionally well for me, though, so I reserve it for areas where I’m actively fighting hyperpigmentation. Right now, that means on my upper lip and around my mouth, where a waxing accident has left me scarred.
  • AHA: AHAs are the acids most likely to give me overexfoliated Cling Wrap Face, so I use my stanky Papa Recipe White Flower Clear Up 8% AHA Gel only on bumps or areas threatening to get bumpy. Right now, I dab a bit on my forehead and chin.
  • BHA: Since I rely on my COSRX BHA Blackhead Power Liquid only to keep my visible pores clear and clean, it goes just on my nose, often with a cotton pad because COSRX’s Hye Young said that that’s the best way to do it and Hye Young is awesome and I want to steal her cat. I mean cuddle her cat.
  • Spot treatment: While my COSRX Natural BHA Skin Returning A-Sol is not an “active” per se, as its concentration of BHA is too low and its pH too high for exfoliation, I’m including it here because of the many questions that are asked about the placement of this product in a skincare routine. When I have active breakouts or suspect it would be a good idea to whip out my A-Sol and use it as a preventative step, I do it after my pH-dependent actives. Sometimes I tap my A-Sol only on problem areas. In times of great trouble, however, I rub my A-Sol all over.
Cosrx Natural BHA Skin Returning A-Sol
I’ve really missed talking about my A-Sol. Have you guys missed hearing about my A-Sol?

Of course, the actual configuration of your multitasking actives face will depend on your own skin’s needs. The main point is use your acids precisely, only where you want their effects, and to avoid using all of them all over  your face. Your skin will still get what it needs, and your barrier will thank you!

My recommended chemical exfoliants

Although my beauty stash page contains a list of the actives currently in play in my own routine, bloggerlife dictates that what I have open right now isn’t always what I consider the best. So here are the acids I actually recommend and repurchase whenever those spots are open.

  • OST C20 vitamin C serumVitamin C: I’ve personally only used OST C20 and C21.5 vitamin C serums extensively. Of the two, I prefer the C20, which I find significantly more effective at fading hyperpigmentation than C21.5. C20 does have some cons, such as a sticky finish and tendency to oxidize fast if not placed in the refrigerator in between uses, but this product has the right concentration of L-AA at the right pH, for under $20. ( $14.99, Wishtrend* | $16.20, Amazon Prime*) If you’re looking to invest in a more serious vitamin C serum for full-face anti-aging purposes, Skinceuticals C E Ferulic is the patent-holding OG, with vitamin E and ferulic acid and a very low pH for optimal effectiveness ($134.50, Amazon Prime*). Paula’s Choice Resist C15 Super Booster is also well formulated and well regarded ($48, Paula’s Choice*).
  • AHA: After I finish up my smelly bottle of Papa Recipe White Flower 8% AHA, I’ll be going back to my original love, COSRX AHA 7 Whitehead Power Liquid. The thin consistency of this product makes it easy to layer and work with. It’s quite gentle as far as full-strength AHAs go, yet effective enough to keep bumps at bay. Outstanding! ew($14.40, Jolse | $14.40, Wishtrend* | $14.97, Amazon Prime*)
  • BHACOSRX BHA Blackhead Power Liquid keeps my pores nice and clean without drying the crap out of my face like Stridex does, and without leaving an unpleasant oily residue like the Paula’s Choice BHA I used ages ago. ($16.29, Amazon Prime* | $16.80, Wishtrend* | $16.80, Jolse)

What actives do you use? How do you get the most out of yours?

40 thoughts on “How to Exfoliate: Multitasking with Chemical Exfoliants

  1. This post came just on time. I was actually thinking about using the same method but I wasn’t quite sure. It makes sense to target different areas with different products. I just slapped my acids on my face this way and I’m hoping for the best 😀 Only one thing keeps bugging me – I have these tiny elevated bumps (not inflamed) all over my cheeks and they get very visible when I put blush over. I’m usually using AHA over them (maybe I’m doing it wrong). Fiddy, can you please help? 🙂 Thanks!


  2. Perfect timing with the A-Sol. I could definitely read more about it if you wanna write more lol. I’m going to get it in my next haul and was a little confused where I would place it in my routine. Now, I know. Thanks lady!


    1. I actually reviewed it a long long time ago if you want to dig that up! We always have some in the house because it calms down those big deep inflamed blemishes super fast.


  3. Awesome post as always Fiddy! So I do have a question. How do you fit your Curology prescription around your acids method? Different days? Different times of day? Teach me your ways, oh wise one 😉


    1. Curology goes after acids and I do the Curology every night, acids I’m working back up to most nights when I multitask them like this (I don’t think I’ll ever go back to regularly layering them on top of each other again).


    2. I had the same question. My Curology rx has tret, vit C and niacinamide, which I am extremely grateful for. That cuts a vit c step out of my routine, but I am still getting niacinamide from my essences and ampoules. I am doing my Curology every other night, using Mizon aha/bha clean toner beforehand, and on my off nights Cosrx bha blackhead and the aha whitening power. It’s really working for me! I am so obsessed with Asian beauty.


  4. Have you looked into the drunk elephant c serum? I have been using it with mixed results but after the latest snailcast pod and this post I am realizing that I have probably been teetering on the edge of over-exfoliation. I am going to scale back on the aha use and only do the c-serum every other day which shouldn’t be much of a problem because keeps working long after application. Thanks for all your great posts and good luck with the move! Ps – I am writing this while wearing a naruko snail mask – thanks for introducing me to the brand:)


  5. Hi! Recently I bought Naruko Mandelic acid 5% ampoule. I’d like to incorporate it in my Autumn skin care routine (Hada Labo red bottles line with retinol). How do you feel about this idea? I’ve never tried any acids and I’m a little bit afraid of that mix would be too irritating for my skin.


    1. Mandelic acid is comparatively gentle and 5% is quite low, and the Hada Labo Alpha line also uses a quite weak retinoid at a low concentration, so theoretically you should be good! Just introduce your mandelic slowly–try it once every three days for a couple of weeks and move up from there. Good luck! Don’t forget sunscreen!


    2. Ooh! I’m so curious about the Naruko Mandelic. Have you started using it yet, and how do you think it smells?
      And are you using the whole line of the Hada Labo Alpha products, and what kind of results have you seen so far?
      Sorry to hijack!


  6. Hi! I am currently a BR p50 (around 4x a week at night, used with a damp cotton pad as I’ve realized it’s too much for my skin in its pure form) and Retin-A alternatively. As much love as Kerry over at Skin and Tonics has for the p50, I don’t find myself as in love with it. 😦 And that is why I’m planning to get the CosRX whitehead and blackhead power in lieu of the p50. Do you think that would work out okay? My main skin problem is stubborn closed comedones on the cheek area and occasional whiteheads on the jaw area. I’ve also started to gain interest on the A-Sol as you have an amazing review on it. Hope you could help me out, snail queen! ❤


  7. I used to use samples of Skinceuticals CE Ferulic from eBay but the price went up recently, so I got Timeless vitamin c serum from Amazon and I like it even better. I haven’t found true love with any BHAs or AHAs but I like the oily Paula’s Choice white bottle BHA as well as what Cosrx offers, and I’m looking forward to Stratia’s upcoming mandelic product.


  8. Hi fiddy. I wish I discovered your blog ages ago when I was battling hyper pigmentation and using bad bleaching products. But your reviews have helped me find good products and the scars are almost gone and my skin is so healthy it’s hard to believe. I love your blog please never stop writing!


  9. I also swear by Cosrx’s BHA. I started using this just as the summer hit because I tend to get really bad break outs. I only use it once a day in my evening routine and it has worked very well for me, clogged pores have been kept to a minimum. For an AHA I have a Gylcolic Acid mask from Andalou Naturals that I find works well, I use it a couple times a week. The mask is formulated with honey to help moisturize which feels great. I want to add Vit C to help fade some very stubborn discoloration on my cheeks I think the Vit C serum I have is dick-less (as Snow would say) so thanks for the recommendations!


  10. Do you know whether a product that contain both BHA and AHA will be affected or not. I just started using curology a day or two ago and I don’t think I would be able to incorporate acid into my routine for sometime but I really want to try chemical exfoliating though. Missha just came out with this Super Aqua Smooth Skin Peeling Mousse which contain Triple Acid Complex (AHA + BHA + PHA) 7%, I email them about it and they told me the pH of the product is 6. I couldn’t find anything on the internet regard this but do you think since the product is somewhat high in pH in addition to the fact that you only apply it to the skin for 10 to 15, would it be effective.


    1. If the pH is 6 then it’s only going to be minimally effective but it may be a good place to start so that you can figure out your skin’s tolerance for such things. Go slow and good luck! I might pick myself up some of that since I do like weak acids.


  11. Thanks for this! I feel like I use a TON of actives, but my face doesn’t look over exfoliated (my skin is dry, but it’s always dry) and they don’t seem to do much other than help me maintain the status quo. Since I brought an AHA into the picture over a year ago (then it was Alpha Hydrox 12% AHA soufflé 2x/day (I KNOW RIGHT?) and now it’s CosRx AHA 7 Whitehead Power Liquid 2x/day) my nose and chin area have been going through a slo-mo purge where I’ll get a very purge-style whitehead or two every morning when I wake up but it’s a sloooooowwwwww process. Overall my skin looks brighter than it did when I started but I’ve got a long way to go.

    Anyway, I’m planning to change things up a little by bringing in an LAA Vit C serum (Timeless) once I’m finished with the MAP serum I’m currently using and switching to a stronger AHA, but doing the C in the morning and the AHA in the evenings (instead of both twice/day (I KNOW RIGHT?). Since blackheads on my nose represents my nail BHA troublepoint, I will definitely try your technique with my CosRx Blackhead Power liquid. I work from home so active wait times aren’t really an issue for me but it will still be nice to streamline a little!


  12. I’m old; my face loves acids. Not sensitive, but reactive to the oddest things. Like aloe, which rules out a SL of products. Primarily a PC broad, who has had excellent results, but have added a bit of AB. Use the Resist BHA, which is not widely noted, ams. That is the only Paula BHA that is not oily, and that’s my only info addition in this post, that there actually is one that is not oily. Do not have an established aha, (PC’s have aloe) which I think will be the cos Rx. Back to cosdna, thanks to you snailophiles. Use the Paula clear BHA at night. Think it’s oilier than 2% white bottle. PC vit c. 3x/week. But the multi prods and layering and alternating made me get a small wipe off board for scheduling. Work 3-4 nights week and need something to remind me of the ~6 things I have to do before bed, differing depending on next day’s weather/day job/outdoors/tide table, etc. don’t know if my white board has enough room to add all I want to incorporate. But that does mean some prod from Chel’s holy snails lineup, Mizon snail gel/mist, and a boatload of other stuff. Galactomyces, f’rinstance.


  13. Great post and great tips. I actually use a lots of actives (about 4 COSRX products + C20) and still feel that my skin isn’t exfoliated enough, and end up using mechanical exfoliation (black sugar scrub) once a week. I don’t really know if I’m just exaggerating or that’s what’s right for my dry/dehydrated/sensitive skin (my skin is a mess ikr). Thanks for this great post 😀

    My Korea Obsession | Korean beauty products’reviews, beauty tips and DIYs


    1. Hi! Can I ask what it is about your skin that makes you feel it isn’t exfoliated enough? Some things, like flakiness or rough patches, can actually be signs of overexfoliation.


  14. HI Fiddy, now that you have tried both Papa Receipe AHA and Cosrx AHA, which one do you prefer? I wanted to add AHA to my skincare routine but not sure which to buy. Could you direct me to which would be a better selection and why? Thanks in advance!


    1. They’re both effective AHAs. My personal preference is the Cosrx as I find the smell easier to tolerate (I’m almost done with my bottle of Papa Recipe and I still cannot get used to the odor) but you’ll find many other people say the same but the other way around! Ultimately I think either of them would be a good starter choice.


  15. HIIIHi, im just wondering if it matters at what age we start chemical exfoliation? I’m 21 and brown and i have oily-combo skin. I usually get acne around my time of the month but it stays forever and its big and painful and always leaves a mark!!! My marks are usually brown colored but sometimes red too and they may also leave and uneven texture on my skin sometimes. I was thinking to get the Bha blackhead liquid to clear those scars up; but i dont want it to ruin my skin the in long run. I want to clear my acne up and get rid of my scarring.. so do you think the BHA blackhead liquid is a good thing to start at 21? PLEASE HELP!!!


    1. Hiya! Concerns over starting chemical exfoliants at a young age are not uncommon 🙂 It’s my understanding that as long as you use them safely (not overexfoliating, using sunscreen when using photosensitizing acids) then there’s no particular reason you can’t start at your age. For scarring and pigmentation issues, however, AHAs are more generally recommended than BHAs.


      1. Oh that’s great!!! I just purchased my bha bottle today and am excited to try it.
        I thought bha was geared toward oily acne prone skin? Which is why I chose that one even though I have hyperpigmentation /scarring as well. Do you think the bha will help in that somewhat?


      2. Not that know of. I know that salicylic acid peels can have an effect on pigmentation, but those are very high concentration clinical- or professional-type products, not the gentle daily use ones. But if you have acne that comes from clogged pores, the BHA may help to keep that under control!


  16. I’ve been way behind on my Fiddy-reading! And of course my first comment back is on exfoliation, the topic that got me hooked on to K-beauty to begin with!

    I’m currently using Timeless Skincare’s Vitamin C+E+Ferulic serum. Its HUGE immediately noticeable advantage over C20 is that it does not sting at all, not even a little bit. It also seems to be more stable than C20, since I’m on my 4th month on my 1st bottle and it’s still very, very clear (tip: I split the contents of one bottle in to two, so that I expose less of the serum to air/light every time I use it while latter half remains undisturbed). It weirdly smells like hot dog water, though. So far, it’s done a great job with my PIH.

    Liked by 1 person

  17. Ugh I still just want to use ALL OF THE ACIDS. I currently only have Paula’s Choice BHA, a sample I bought roughly a year ago & it’s still 1/4th full! It works so well and actually isn’t drying at all so I have no doubt about repurchasing it. After the first bout of overexfoliating I now only use it when I feel like I need it; i.e. when a breakout occurs (every day till it’s over) and once or twice a week or when I feel my skin is feeling a bit more rough or just when I’m bored. This works perfectly for me. Also, I did recently notice that during an active breakout, when I incorperate a waiting time my breakout does clear up faster. Then again that might be biased because I look more closely at what my skin is doing and am basically checking what it’s doing every minute versus my more nonchalant approach and usually not waiting at all or very little when not experiencing an active breakout….

    I am super interested in getting an AHA and especially a Vitamin C serum though. The C20 seems perfect for me as I am looking for brightening ingredients atm. Thanks to your concise clear info I seem to not need an AHA because my BHA works well enough for me for breakouts (that is not to say I don’t still want it……….). So thank you! That C20 serum is finally on my ‘to purchase next’ list yay!


  18. Hi Fiddy,
    Skinceuticals C E Ferulic is quite expensive, especially for constant use. What are
    your thoughts on DIY? Do you have any recommendations for recipes etc?

    I too love your idea about actives placement. Which active would you recommend for


    1. If you’re interested in DIY, you should check out Chel’s blog–she actually has a whole series of posts of vitamin C serum recipes and instructions on there and some really great tips about safety, preservatives, etc. It’s Good luck!

      Oh and L-AA is probably my most recommended active for pigmentation, especially because it isn’t photosensitizing like AHAs and retinoids are.


  19. Hi, im breastfeeding and getting hormonal breakouts. This is the worst acne I’ve ever had. I’m so upset with these pimples and marks i have. Is it ok if i use aha and bha actives? I bought only samples just for me not to use it often and i tried them and my acne seems to dry up faster with the aha power liquid. Btw my little one is turning two.


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