The reference exfoliating acid — decades of use and controlled-trial support for texture and tone.
Glycolic acid, the smallest alpha-hydroxy acid, loosens the bonds between dead surface cells so they shed evenly, revealing smoother skin and diluting surface pigment. At higher concentrations and continued use it also stimulates dermal collagen.
Leave-on products at 5–10% are the studied home-use range; the classic trial used 8%. Buffered formulas (higher pH) are gentler but slower.
A classic double-blind trial showed clear improvement at 8%
In a 22-week randomized, double-blind, vehicle-controlled trial, 76% of participants using 8% glycolic acid improved in overall photoaging versus 40% on vehicle. Later histology work confirmed real structural changes, not just surface polish.
Reliable gradual brightening through exfoliation
Controlled trials (mostly of glycolic peels and 8–10% creams) show consistent improvement in mottled pigmentation over 12+ weeks. Works best on surface-level, sun-induced pigment; deeper melasma needs other tools.
Anchored to regulatory assessments — not hazard lists. Dose makes the poison; these are the conclusions at real-world cosmetic use.
CIR concluded glycolic acid is safe for consumer use at ≤10% at pH ≥3.5. AHAs increase sun sensitivity — daily sunscreen isn't optional with this ingredient.
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