AHA vs. BHA: What’s the Difference?

At this point, it’s probable that you’ve heard of AHAs and BHAs—otherwise known as alpha hydroxy acids and beta hydroxy acids. It’s even likely that they’re already in your skin care routine. But could you tell someone what sets AHAs and BHAs apart? If you’re currently hesitating to say no, don’t worry. Soon enough you’ll be able to share your AHA and BHA knowledge with all your friends. With the help of ethnic skin expert, SkinCeuticals ambassador, and Skincare.com consultant Dr. William Kwan, we’re sharing everything you need to know about the difference between AHAs and BHAs—plus, how to know which one is right for your skin!

What’s the Difference Between an AHA and a BHA?

While the FDA confirms that both AHAs and BHAs are methods of chemical exfoliation to remove dead skin cells from the surface of the skin, according to Dr. Kwan, there are two significant differences to keep in mind. AHAs are water soluble with a small particle size, while BHAs are oil soluble with a large particle size. These two points of differentiation impact who should add an AHA to their skin care routine and who would be better off updating their regimen with a BHA. More on that, next.

Who Should Use an AHA and Who Should Use a BHA?

AHAs and BHAs can be used to address and manage different skin conditions. Dr. Kwan recommends AHAs to those looking to help diminish the appearance of fine lines, wrinkles, and sun damage. BHAs, on the other hand, are better suited for oily, acne-prone skin because according to Dr. Kwan, the large particles “can rest on pores and can help with acne.” According to the FDA, both AHAs and BHAs can help improve the appearance of skin texture and tone with continued use over time.

What Are the Most Popular AHAs?

As we previously mentioned, AHAs in general are incredibly popular. However, there are specific AHAs that are receiving the most attention. Kwan shares that glycolic and lactic acids are the two AHAs most often found in skin care products.

If you think your regimen is in need of an AHA, try SkinCeuticals Purifying Cleanser. The cleansing gel—formulated with glycolic acid—can help remove surface impurities, smooth a rough texture, and refresh the skin.  

What Are the Most Popular BHAs?

While there are a multitude of AHAs found in skin care formulations, formulas featuring BHAs aren’t nearly as diverse. There’s one ingredient that’s most commonly known as a BHA and chances are, if you’ve ever dealt with acne, you’ve already used it—it’s salicylic acid.

BHAs can be found in nearly any form that suits your fancy, whether that’s a cleanser or a body cream. Some formulas even combine AHAs and BHAs, like SkinCeuticals LHA Toner. This toner—ideal for combination to oily skin types that are prone to breakouts—features a blend of salicylic acids, as well as additional exfoliating agents lipo-hydroxy acid and glycolic acid—and can help exfoliate the skin to reveal a brighter, more even-looking complexion.

What Should You Know Before Adding AHAs and BHAs to Your Routine?

Face scrubs and other forms of manual exfoliation can cause unwanted skin dryness, and in that sense, chemical exfoliators like AHAs and BHAs are no different. Dr. Kwan is always careful to caution patients that products formulated with these types of acids can dry out and irritate your skin, which makes it important not to over-exfoliate. Closely follow the instructions on your chosen product and if your skin still seems dry after use, consider creating a schedule where you only use it on certain days of the week to give your skin a break.

Additionally, if you choose to join the chemical exfoliation trend, you’ll need to up your sun protection game because both AHAs and BHAs may increase your skin’s sun sensitivity. That means it will be extra important to follow the FDA’s guidelines for sun safety, including broad-spectrum sunscreen applications (with an SPF value of at least 15) on all exposed areas of skin prior to heading outdoors, reapplying every two hours, staying out of the sun during its peak hours (between 10 a.m. and 4 p.m.), and covering up with protective clothing and accessories. 

Want to learn more about acids? Check out our ultimate guide to acids in skin care here!