AHA

Mechanism and Types

AHAs work by dissolving the bonds between dead skin cells on the surface (stratum corneum), promoting cell turnover and revealing fresher skin beneath. Common AHAs include glycolic acid (smallest molecule, most penetrating), lactic acid (gentler, hydrating), mandelic acid (larger molecule, gentle), and citric acid.

Concentration and pH

AHA efficacy depends on both concentration and formulation pH. Products must maintain a pH between 3-4 for effective exfoliation. Higher concentrations (10-30%) are used in professional peels, while daily-use products typically contain 5-10%. Free acid value, not total acid content, determines activity.

Skin Benefits

Regular AHA use improves skin texture, reduces hyperpigmentation, diminishes fine lines, and enhances radiance. AHAs also stimulate glycosaminoglycan and collagen production in the dermis over time, providing anti-aging benefits beyond surface exfoliation.

OSF Perspective

OSF considers AHAs foundational to modern skincare literacy — understanding chemical exfoliation empowers consumers to move beyond abrasive physical scrubs toward gentler, more effective resurfacing.

Related Terms

BHA  |  Active Ingredient  |  Retinoid  |  Skin Barrier  |  pH Balance in Skincare

Notable Brands

The Ordinary, Drunk Elephant (T.L.C. Sukari), Paula's Choice, Sunday Riley (Good Genes), Pixi (Glow Tonic)