What is the difference between AHA, BHA, and PHA?

AHAs are commonly used for surface texture, while salicylic acid, a BHA, can help with blackheads and whiteheads. The ingredient family gives us a starting point, but the finished product and the skin's current tolerance decide whether it is actually appropriate.

AHA, BHA, and PHA are not interchangeable

AHAs, BHAs, and PHAs belong to different exfoliating families, but the ingredient family does not tell you how strong the finished product will feel.

Choose the acid around the concern and tolerance

The concern being treated, concentration, formula, frequency, and the rest of the routine matter. If the skin is already stinging, I would not choose another acid until it settles.