Glycolic Acid (3.01 %)
Glycolic acid is an alpha-hydroxy acid (AHA) — the smallest and simplest of the AHA family — with CAS # 79-14-1. It occurs naturally in grapes, sugar cane juice, sugar beet, and Virginia creeper leaves, but the cosmetic-grade version is most often synthetic. Its small molecular size allows it to penetrate deeply into the skin. In formulations, effectiveness is strongly dependent on both concentration (typically 4–20% for at-home use) and pH (optimal range 3–4).
Glycolic acid gently lifts dead skin cells to reveal fresher, smoother skin and has clinically demonstrated ability to stimulate collagen synthesis, resulting in firmer, younger-looking skin over time. It can disperse melanin and fade hyperpigmentation including post-inflammatory hyperpigmentation (PIH) from acne. It also increases skin thickness, improves skin renewal, and enhances penetration of other skincare actives.
Increases skin sensitivity to UV radiation — daily sunscreen use is essential. Stronger concentrations (above ~10%) may cause stinging, burning, visible peeling, redness, or irritation; over-exfoliation should be avoided. Not recommended for very sensitive or rosacea-prone skin; BHA or PHA alternatives are suggested in those cases. Concentrations above 20% are considered professional territory. Product must be at an acidic pH (ideally 3–4) to be effective; above pH 5 the ingredient loses efficacy.
