What Is the Difference between AHAs and BHAs?

What is the difference between AHAs and BHAs? When exfoliating, It’s important to understand when to use an AHA versus a BHA. AHAs and BHAs both exfoliate, give a glow, and help with minor fine lines and acne. Likewise, how do we actually tell the difference? Well, AHAs are water soluble meaning you'll find them more in water-based products, and they're probably better for drier skin types. On the other hand, BHAs are oil soluble, and there's only one that we use in skincare. It's called salicylic acid. So, whenever you see “BHA” in skincare, it’s synonymous with salicylic acid.

If you want to wick away oil, BHAs are probably the best option because they can get into those deeper layers of the skin like the sebaceous unit. 

When we look at the anatomy of the skin, oil is located on the acid mantle on the top layer of the skin, and its created in the sebaceous gland, those little glands that pump out oil into the hair follicle and onto the surface. So, using an oil-soluble serum like a BHA allows skincare to funnel down into the skin barrier where it can do its work. BHAs are awesome. They are exfoliating, and they're also really good at getting rid of acne. If you are someone who is breakout prone and has super oily skin, BHAs are probably going to be your best friend.

AHAs are slightly different. While there's only one major BHA, salicylic acid, there are many types of AHAs. Some of the most popular are the most potent like glycolic acid which comes from sugarcane or lactic acid. Lactic acid is also an AHA, and it comes from fermented bacteria or soured milk. Next, there's tartaric acid derived from grapes. In addition, there’s mandelic and malic acid that come from different fruits like apples, pears, or almonds. The good thing about these AHAs is that they are water-soluble. There's a concentration of water on the top layer of our skin or the stratum corneum. The stratum corneum is basically our dead skin cells squished together, held together by things like desmosomes. 

But, we need an exfoliant that will sit on top of the skin to break down these desmosomes so the dead skin cells can exfoliate. Some AHAs like glycolic acid are small enough to penetrate deeply into the skin and promote new skin cell growth and luminosity. These AHAs can actually dissolve the proteins that our skin is made up of, that dead keratin or dead keratinocytes. 

AHAs are slightly better for those who have drier skin. Not only are AHAs water soluble, but they can bind and combine with water. So, if you do have other water-based products in your routine, they will help retain that water. AHAs can be used for acne too, but they can also be wonderful for fine lines, discoloration, and wrinkles. 

Enzymes and physical scrubs can also help with luminosity, but Cassandra loves AHAs and BHAs because they exfoliate more deeply and evenly. Here are some that Cassandra recommends.


Ordinary AHA + BHA peel - $9.50


Paula’s Choice AHA BHA - $28.90 


Inkey List BHA Serum - $12.99



Inkey List PHA toner - $12.99


The Ordinary lactic acid - $10.50


Wishful Skin Yoyo glow - $39 

Paula's Choice Purple AHA BHA -$42



Inkey List salicylic cleanser -$11.99 


Face Reality Mandelic Acid Serum -$40