BHAs or beta hydroxy acids are like AHA’s little sisters. BHAs (e.g. salicylic acid) basically do the same thing to your skin, and have a similar effect to AHAs, only they’re oil-soluble, and so clean a little deeper than AHAs. For this reason, they’re better suited to people with oily and acne-prone skin. Give Paula’s Choice Skin Perfecting 2% BHA Liquid Exfoliant a whirl.