Alpha-hydroxy acid (AHA) with the smallest molecular weight in the group. Accelerates desquamation, evens skin tone and texture.
Topical application
AProven efficacy. Two or more independent RCTs with instrumental endpoints.
One of the most extensively studied AHAs. RCTs and systematic reviews confirm efficacy for acne, melasma, photoaging, and keratosis. Professional peels at 20–70% concentrations have extensive clinical evidence.
1–10% in leave-on products; 20–70% peels – professional use only
Glycolic Acid (Hydroxyacetic Acid) is an alpha-hydroxy acid (AHA) with the smallest molecular weight in this group (76 Da). Obtained from sugarcane or synthetically. The deepest-penetrating AHA – active in the dermis at the right concentration and pH. Mechanism. Dissolves the corneocyte bonds of the stratum corneum – accelerates desquamation. Stimulates collagen and glycosaminoglycan synthesis in the dermis (Bernstein 2001), reduces hyperpigmentation, evens texture. Where applied. OTC serums and toners (5-10%, pH 3.5-4), professional peels (20-70%, pH 1.5-3). Brands include The Ordinary Glycolic Acid 7%, NeoStrata, Pixi Glow Tonic, Spanish Sesderma Acglicolic, Mesoestetic Glycolic Acid. Evidence base. AAD 2024 and Cochrane 2020 classify glycolic acid as first-line for photoaging, post-acne marks, melasma, hyperkeratosis. Sharad 2013 in 50 women over 12 weeks of 10% glycolic acid: texture, tone, wrinkle improvement in 80% of participants. Safety. CIR/SCCS confirm safety up to 10% OTC at pH ≥ 3.5, up to 70% in professional peels under dermatologist supervision. Irritation, peeling, and erythema in the first 1-2 weeks in 30-50% of patients. Photosensitizes – daily SPF 30+ mandatory. Pregnancy – safe at OTC concentrations (SAFE per SEGO 2023). Deep professional peels (>30%) are postponed in pregnancy. Lactation – use with caution: avoid breast application. Suitable for. Photoaging, post-acne marks, melasma, uneven texture, follicular hyperkeratosis. Not suitable: sensitive skin, active rosacea, eczema, dermatitis. Alternative – PHA (gluconolactone).
Irritation potential
MediumAllergen risk
LowPregnancy
SafeDoes not combine with
The Evigrade extension adds an evidence panel to Wildberries, Goldapple, Letu, iHerb, Sephora and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Glycolic Acid is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
Glycolic Acid suits: normal, combination, oily. Use with caution in: sensitive, dry.
Glycolic Acid has moderate irritation potential. Sensitive skin may show a transient reaction that usually settles with adaptation.
Alpha-hydroxy acid (AHA) with the smallest molecular weight in the group.
The INCI name is Glycolic Acid. It may also appear as: Hydroxyacetic Acid, Гликолевая кислота.
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For sensitive skin
Risk of burning and irritation with prolonged contact. Products containing glycolic acid require daily SPF30+ sun protection.
Suitable for
Use with caution
Two acid exfoliants at once are excessive. Alternate: AHA one evening, BHA another, to avoid barrier overload.
1–10% in leave-on products; 20–70% peels – professional use only