Chemical exfoliants dissolve the "glue" between dead surface cells, revealing smoother, brighter skin — no scrubbing required. But AHA, BHA, and PHA do different jobs, and picking the wrong one is the fastest way to end up red and irritated.
AHAs — for surface and tone
Alpha-hydroxy acids (glycolic, lactic) are water-soluble and work on the skin's surface. They're best for dullness, rough texture, and uneven tone. Glycolic is the strongest; lactic is gentler and also hydrating, making it friendlier for dry or sensitive skin.
BHAs — for oil and pores
Beta-hydroxy acid (salicylic) is oil-soluble, so it penetrates into pores and clears congestion. It's the top choice for oily, acne-prone, and blackhead-prone skin.
PHAs — for sensitive skin
Poly-hydroxy acids (gluconolactone) are larger molecules that work more slowly and gently on the surface — a good entry point for sensitive or reactive skin that can't tolerate stronger acids.
How to choose and use
- Dull / rough / uneven tone → AHA.
- Oily / breakouts / clogged pores → BHA.
- Sensitive / just starting → PHA or gentle lactic acid.
Start once or twice a week, not daily, and always wear sunscreen — acids increase sun sensitivity. Don't stack strong acids with retinoids on the same night when you're beginning.
Bottom line
Match the acid to your goal: AHA for tone and texture, BHA for oil and pores, PHA for sensitivity. Go slow, and protect with SPF.
FAQ
What's the difference between AHA and BHA?
AHAs (glycolic, lactic) are water-soluble and work on the surface for tone and texture. BHA (salicylic) is oil-soluble and gets into pores, making it ideal for oily, acne-prone skin.
Which exfoliating acid is best for sensitive skin?
PHAs (like gluconolactone) or gentle lactic acid — they exfoliate more slowly and are less likely to irritate reactive skin.
How often should I use a chemical exfoliant?
Start once or twice a week and build up only if your skin tolerates it. Daily use is too much for most people, especially early on.
Do I need sunscreen when using acids?
Yes, always. Exfoliating acids increase sun sensitivity, so daily SPF is essential to avoid irritation and pigmentation.