Exfoliators

Two to three times a week for most skin. Daily use of a chemical exfoliant is where irritation, redness and a compromised barrier usually start.

AHA (glycolic acid) works on the surface for tone and texture. BHA (salicylic acid) is oil-soluble and gets inside the pore, so it's the better choice for blackheads and oily, congested skin.

Not recommended — that combination is one of the most common causes of a damaged barrier. Alternate nights instead, and see Dehydration & Barrier Repair if you're already seeing signs of it.

For the face, a chemical exfoliant is usually gentler and more even. Physical scrubs and exfoliating towels work better on thicker body skin — see Scrubs & Exfoliators for those.