Also known as: AHA, Alpha-Hydroxy Acid, Hydroxyacetic Acid
Glycolic acid is an alpha-hydroxy acid (AHA) with the smallest molecular weight of all AHAs, allowing the deepest penetration. It loosens the bonds between dead skin cells, accelerating cell turnover and revealing brighter, smoother skin. At higher concentrations it stimulates collagen production. Effective at pH 3.0–4.0. Increases UV sensitivity, so SPF use is essential.
Comedogenicity ratings are based on the rabbit ear assay model. Individual skin responses vary. See our article on comedogenicity ratings for context.
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