Five minutes, then stop
AHA vs BHA
AHAs are water-loving surface acids. BHA is oil-loving and the usual pore acid. You rarely need both in one night.
Updated 27 Aug 2026 · 6 min read · AHA vs BHA
Water versus oil
AHAs dissolve in water and work on the surface. Glycolic is small and punchy; lactic is a bit kinder and a bit more humectant; mandelic is larger and slower. BHA (salicylic) likes oil, so it is the usual choice for blackheads and a congested T-zone.
A 30% peel is a different product from a 5% leave-on. Do not import a peel schedule from a video into a 2% bottle.
Pick one problem
Dull, dry, ‘I want glow’: lactic or mandelic. Congested, oily, makeup sitting on bumps: BHA. Both: alternate nights, not a cocktail, and only if the barrier is quiet.
- AHA: surface, glow, dry texture
- BHA: pores, oil, makeup grit
- Neither: a stinging face — cream instead
The morning after
Acids increase how easily you burn. SPF 30 or 50, two fingers. If you cannot be bothered with sun, do not be bothered with glycolic. $8–$22 for a decent acid. A $70 ‘AHA/BHA/PHA’ stack is three ways to overdo Tuesday.
Questions, answered
- Can I use BHA every day?
- Some 2% lotions are written that way. Many faces do better 3–4 nights. If you flake, you have the answer.
- Glycolic or lactic?
- Lactic if you are dry or newer. Glycolic if you already tolerate acids and want a stronger surface hit.
- With vitamin C?
- Not in the same minute as a default. C in the morning, acid at night, or alternate mornings.
