Everything You Need to Know About Salicylic Acid

Salicylic acid is one of the most reliable over-the-counter solutions to persistent breakouts. Slather some on a pimple before you go to bed and often, the pimple’s dried up and much less noticeable by the time you wake up.

But what exactly does salicylic acid do? And how do you know if you’re using it in the right situations? Keep reading.

What is salicylic acid?

This is going to get a little technical, but nailing down the exact structure of salicylic acid is important in explaining why and how it works so well.

There are two categories of acids among skincare products: beta hydroxy acids (BHAs) and alpha hydroxy acids (AHAs). Salicylic acid is a BHA, which means the hydroxy part of the molecule is separated from the acid part by two carbon atoms. In AHAs, they’re separated by a single carbon atom.

The small difference in their structures is significant. Both AHAs and BHAs exfoliate the skin, but AHAs are water-soluble, while BHAs are oil-soluble. Generally, oil-soluble ingredients penetrate the skin’s pores more easily, which makes them more capable of unclogging them.

Once it penetrates the skin, salicylic acid not only dissolves whatever debris is clogging the pores it also acts as an anti-inflammatory and helps inflamed pimples and pustules clear up faster.

It’s most effective against blackheads and whiteheads

Salicylic acid can help with cystic acne to a degree because of its antibacterial activity, but it’s most effective against classic blackheads and whiteheads. That’s because it can directly dissolve the debris clogging pores and regulate the skin cells.

Which salicylic acid product is right for you?

The answer to this question is going to depend largely on the severity of your acne. For mild cases that occur every so often, a spot treatment, especially one that’s applied at the onset of a breakout, can work well. A salicylic acid-containing acne wash can also be helpful.

The Food and Drug Administration allows manufacturers to make acne-fighting claims for salicylic acid-containing products if they use it at concentrations between 0.5% and 2%. (For context, chemical peels performed at a dermatologist’s office may have concentrations of 20% to 30%.) If you’re new to salicylic acid, start at the lower end of the spectrum and see how your skin reacts to it before using something stronger.