What’s the difference between AHAs and BHAs? Here’s what you need to know

February 14, 2024

We know how important it is to understand what you are putting on your skin. By now, you may have heard about alpha hydroxy acids (AHAs) and beta hydroxy acids (BHAs) and how essential they are for maintaining youthful-looking skin. Next to using sunscreen every day, a well-formulated AHA- or BHA-based treatment is critical to maintaining a healthy, hydrated, more even-toned complexion. Dr. Howard Murad (board-certified dermatologist, pharmacist and founder of Murad Skincare) was one of the pioneers of using AHAs in topical skincare and modernizing the science of skincare. Let’s look at the difference between AHAs and BHAs to determine which is right for you.

What are AHAs?

AHAs (alpha hydroxy acids) are naturally occurring substances found in various fruits, sugar cane and sour milk. Glycolic acid, the AHA found in sugar cane, is used in many skincare products because it is especially well-suited for use in skincare.

How do AHAs work on skin?

The main benefit of AHAs is their ability to exfoliate the skin to repair dry, aging and sun-damaged skin. Glycolic acid works by loosening the bond that holds together the top layers of dead skin cells. By removing the excess build-up on the surface of the skin, AHAs allow newer, softer, healthier-looking skin to emerge. An additional benefit to clearing excess buildup is that moisturizers and treatments can penetrate better.

AHAs also help with age spots and skin discoloration, and the reduction of fine lines and wrinkles. Using AHAs does, however, make your skin more vulnerable to damage from the sun—a concern with any kind of exfoliating treatment. So always use an SPF 30 sunscreen or an SPF moisturizer with an SPF of 30.

What are BHAs and how do they work?

BHAs are more commonly known as salicylic acid. The main difference between AHAs and BHAs is oil solubility. AHAs are water soluble only, while BHAs are oil soluble. This means BHAs get down into the pores to cut through the oil that’s clogging them. They also have antibacterial and anti-inflammatory properties, so BHAs are perfect for treating acne-prone skin and blackheads. The most common BHA in skincare products is salicylic acid, which occurs naturally in willow bark and sweet birch. Like AHAs, BHAs make your skin more vulnerable to damage from the sun, so always use an SPF 30 sunscreen or an SPF moisturizer with an SPF of 30 to protect your skin.

The views expressed in this article do not necessarily represent the views of Murad, and are for informational purposes only, even if the advice of physicians and medical practitioners are included. This article is not a substitute for professional medical advice, diagnosis or treatment, and should not be considered specific medical advice.  

About the Author

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Jacki Marzano is SoCal-based storyteller and head copywriter at Murad Skincare. She's shaped the voice of some of the most recognized beauty brands in the business, has a penchant for sharing homemade cookies, and believes SPF is the secret to getting carded well into your 40s.