Exfoliants: Should I use AHAs or BHAs - which one is better?

Having quite oily and congested skin myself, I exfoliate on the regular. But nowadays there are so many exfoliating products on the market that choosing one can be really overwhelming, this is also true for myself. That is why I decided to dedicate a blogpost on exfoliants. We’re going to discuss the two groups of (chemical) exfoliants; what are they, what can they do for your skin, and which ones should you use? Keep reading!

Why exfoliate?
Our skin naturally sheds dead cells every day, but certain factors can slow this process down. Aging, sun damage, genetics, dry or oily skin can all slow down natural exfoliation and result in dead skin cells accumulating on the skin. This leads to dull, flaky skin, clogged pores, blemishes, and acne. We can help the skin exfoliate buildup dead cells and reveal the beautiful, soft, hydrating skin that hides underneath with gentle exfoliants like AHAs and BHAs.

How do AHAs and BHAs work?
AHAs (Alpha Hydroxy Acids) and BHAs (Beta Hydroxy Acids) remove the ‘glue’ that holds dead skin cells together. Once the bonds are broken, the skin naturally sheds, and you’ll be able to see the bright, youthful skin that has been hiding beneath.

AHAs
AHAs are water soluble and work on the skin’s surface. AHAs are humectants, meaning they can retain moisture, hence they are preferred for dry and damaged skin. AHAs are derived from natural substances. Most commonly used AHAs used in skincare include:

-Lactic acid from milk
-Glycolic acid from sugar cane
-Malic acid from pears and apples
-Citric acid from oranges and lemons

AHA concentrations must be less than 10% to follow FDA guidelines. Typical concentrations range between 5-10%. To work effectively AHAs must be formulated within a pH of 3 and 4.

BHAs
BHAs on the other hand are oil soluble. They not only work on the skin’s surface, but also penetrate deeper and unclog pores and treat blemishes. This is why BHAs are preferred for those with normal to oily skin. BHAs have natural skin-calming properties, as well as anti-inflammatory and antibacterial activities and therefore can benefit those prone to redness and rosacea. The most commonly used BHA in skincare is Salicylic Acid, derived from Willow Bark.
BHA concentrations must be less than 2% to follow FDA guidelines. Typical concentrations range between 1-2%. To work effectively BHAs must also be formulated within a pH of 3 and 4.

How to use AHA and BHA exfoliants?
So which one should you use? AHAs and BHAs both diminish fine lines, they make your skin firmer, they smooth out rough skin, and they both improve dull, uneven skin tone. No wonder that they are very popular products within the Korean skincare beauty routine. The main difference between AHAs and BHAs stems from their solubility; AHAs are water soluble and affect the skin only superficially, while BHAs are oil soluble and penetrate deeper. So if you’re looking to exfoliate dry skin, you can best look for an exfoliant with AHAs, but if your looking to unclog pores and remove blemishes, you might benefit more from BHAs. But each individual skin reacts differently to different acids, so you may have to experiment first and look which one suits your specific skin best. One thing you can do is combine both types of acids. Please note that using either one acid on its own will provide amazing results, you absolutely do not have to combine exfoliants to get good results. But there’s nothing wrong with combining both acids to see which one works best for you.

A couple things to keep in mind when combining AHAs with BHAs:
-Incorporate Hydroxy Acids slowly into your skincare routine. Start with a single treatment per week and work your way up. This way you can see how your skin reacts.
-Once your skin has become accustomed to the acids, you can alternate between them; using both acids at the same time will be too much for most people. Alternate days, e.g. use an AHA on monday and a BHA on tuesday.
-A tip for combination skin: apply BHAs to oily areas with large pores, and AHAs to dry areas.
-Apply exfoliants to your neck and chest! Hydroxy acids can also do wonders on your neck and chest.

Side effects
Common side effects of AHAs and BHAs include:
-Mild stinging and redness upon application
-Skin may initially become flaky, but this should clear up as the cells begin to shed
-Higher sensitivity towards sunlight. Make sure you wear sunscreen when you’re out in the sun, especially if you apply exfoliants to your skin in the morning.

References
Clinical, Cosmetic, and Investigational Dermatology, August 2015, pages 455–461
Dermatology Research and Practice, February 2015, ePublication
Journal of the German Society of Dermatology, July 2012, pages 488–491
Evidence Based Complementary and Alternative Medicine, June 2011, ePublication
Clinical, Cosmetic, and Investigational Dermatology, November 2010, pages 135–142
Journal of the American Academy of Dermatology, April 2007, pages 651–663
Jundishapur Journal of Natural Pharmaceutical Products, January 2012, pages 9-10.
Clinical, Cosmetic, and Investigational Dermatology, November 2010, pages 135-142.