By request from the awesome Angelanrenee of BeautyandtheCat’s Beauty Blog, it’s time to talk about chemical exfoliation!
Exfoliation in general is vital to achieving bright, smooth, and healthy-looking skin. Unless removed, dead skin cells will build up on the surface over time, leading to a dull, rough appearance; flakiness; and possibly clogged pores and breakouts. Like a lot of people, I enjoy using a scrub once in a while, but physical exfoliation isn’t something I recommend doing every day. In the first place, it can be messy and labor-intensive, at least compared to chemical exfoliation, and in the second place, too much physical exfoliation can be irritating and lead to broken capillaries. For that reason, I prefer chemical exfoliation for day-to-day maintenance.
There are two main categories of chemical exfoliants: alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs). AHAs and BHAs serve different purposes and work very well together as part of a well designed daily skin care routine. They should be approached with caution at first, though. Don’t start using both products at the same time, and don’t use them every day until you know your skin will tolerate them well. I suggest starting with an AHA and working your way up from once every other day to once a day, then twice a day if you can stand the wait time in the morning, which I personally can’t. Same goes for BHAs.
Alpha hydroxy acids are water-soluble chemical exfoliants that help to exfoliate surface skin by dissolving the bonds between cells so that dead skin can shed more easily. It’s important to note that they don’t dissolve the dead skin itself. Nor do they work instantly, as I’ve heard some people claim. At daily use concentrations of between 5 and 10 percent, AHAs simply accelerate and optimize the skin renewal process.
AHAs are useful for:
- Brightening skin
- Making skin tone more even
- Reducing hyperpigmentation caused by acne scarring
- Reducing fine lines
AHA cautions and best practices
When using AHA products, sunscreen is extremely important. AHAs are photosensitizing, which means that they increase your skin’s sensitivity to the sun. If you use AHAs, even if you only apply them at night, sun exposure without adequate UV protection will lead to increased sun damage. You know that I already consider sunscreen absolutely essential for fighting wrinkles and maintaining healthy, youthful skin. It is even more essential when using AHAs. If you use AHAs but choose not to wear sunscreen, you’ll be undoing any benefits you might get from your AHA product.
As a final note, the pH of AHA products will make or break the product’s effectiveness. In order to exfoliate, AHA products must be at a pH between 3 and 4. If the pH is below 3, the product is too acidic, and you’ll run the risk of chemical burns (luckily, however, I’ve never heard of an AHA product with a sub-3 pH). If the pH is higher than 4, it just won’t work.
Beta hydroxy acids (BHAs) are oil-soluble chemical exfoliants that behave in a similar fashion as AHAs but that are able to get down into pores in order to clear them out at a deeper level than AHAs, thanks to the oil solubility of BHAs. The most commonly known and used BHA is salicylic acid, which is apparently not actually a BHA, but for the purposes of a chemical exfoliation discussion, it might as well be. For daily use, BHAs are typically found in 2% concentrations but sometimes 4% as well. BHAs are useful for:
- Clearing dirt, oil, and dead skin cells out of pores, especially the typically more visible ones on and around the T-zone
- Reducing inflammation
BHA cautions and best practices
Like AHAs, BHA products must be at a pH of between 3 and 4 in order to work properly while still being safe for skin. While BHA products will still provide some anti-inflammatory benefits at higher pH levels, they will not be able to exfoliate or clear pores. Additionally, many people find BHAs drying, so make sure you have enough hydration and moisturization in your routine before trying out a BHA.
Using AHAs and BHAs together
Since AHAs and BHAs are effective for different skin concerns, many people, including me, choose to use both in the same routine. Here are some tips for doing so:
- Use your AHAs and BHAs as soon after cleansing as possible. The closer they can be to bare skin, the more effective they will be, and since they’re pH-dependent, you won’t have to worry about whether the higher pH of other products will interfere with the acids’ exfoliating actions. I use them right after my vitamin C serum, since my vitamin C serum is also at a pH of between 3 and 4.
- Use your BHA first, then your AHA. That way, the BHA can get deeper into blocked or dirty pores as well as prepare the rest of your face for your AHA.
- After applying your acids, wait at least 20 minutes before applying the rest of your routine. That’s about as long as it takes for the acids to neutralize, so waiting will allow your AHA and BHA products to work to their maximum potential.
- Don’t bother with AHA or BHA cleansers or other wash-off products. They don’t stay on the skin long enough to have any exfoliating effect and are most likely not at the correct pH, anyway.
Why do I use Western AHAs and BHAs instead of Asian ones?
I may be wrong about this, but it seems to me that AHA and BHA products have only recently begun to gain some popularity in the Korean skin care market. That is, at least, how it looks to me. Asian lines often focus more on scrubs, “peeling”-type products, and other forms of physical exfoliation. Lines like CosRX are starting to gain traction for their AHA and BHA products, however, and Mizon makes an AHA serum, which I’ve heard is effective and at the right pH, so I’m sure I’ll be trying out some Asian chemical exfoliants in the future. For now, however, I’ll be sticking to my Stridex pads for BHA and my Paula’s Choice gel for AHA.
I’ve tried to break AHAs and BHAs down into something easy to understand, but if you want to take a deeper dive into the chemistry behind chemical exfoliation, check out Hoojoo Beauty’s post on chemical exfoliation.
Do you use any chemical exfoliants, or do you prefer physical exfoliation? Why?