acidWell-Known
PHA (Polyhydroxy Acids)
Also known as: Gluconolactone, Lactobionic Acid, Galactose
Medically reviewed by ChokChok · Updated April 15, 2026
The gentler cousin of AHAs — exfoliates on the surface without the irritation risk.
What It Does
Gentle exfoliationBrightensHydratesAntioxidant
Deep Dive
Polyhydroxy acids (gluconolactone, lactobionic acid, galactose) have larger molecular structures than AHAs/BHAs, which means they stay at the stratum corneum instead of penetrating deeper. That translates to genuine exfoliation, brightening, and hydration with dramatically less irritation. Rosacea-friendly. Often the first acid dermatologists recommend for reactive skin.
Best For
SensitiveDry
Pairs Well With
Effective Concentration
2–10% typical. Much gentler than AHAs — molecule too large to penetrate deeply.
