Category: topical
Aliases: Hydroxyacetic acid, AHA
Two-carbon α-hydroxy acid. Smallest AHA — penetrates the stratum corneum efficiently and disrupts corneodesmosome cohesion (sulfotransferase-like disruption of cholesterol-sulfate-mediated adhesion) → accelerated desquamation. Chronic low-concentration use thins the stratum corneum, increases viable epidermal thickness, stimulates dermal GAG and collagen synthesis, and disperses melanin. Free-acid fraction (effective pH <4) drives both efficacy and irritation; formulations buffered to pH ~3.5 sit near the efficacy/tolerance balance.