Glycolic Acid vs Lactic Acid
Which is right for your skin?
Both are AHAs; glycolic is the smallest molecule (strongest, more potential sting), lactic is larger, gentler, and also hydrating. New to acids or sensitive? Start with lactic.
Exfoliates the surface of your skin to smooth rough texture and fade dullness. The strongest of the AHAs, so start slow.
A gentler exfoliator that also hydrates as it works. Good entry point if you have sensitive skin and want to try acids.
Can you use Glycolic Acid and Lactic Acid together?
Yes — Glycolic Acid and Lactic Acid are documented to pair well together.
You want exfoliating. Exfoliates the surface of your skin to smooth rough texture and fade dullness. The strongest of the AHAs, so start slow.
You want exfoliating, hydrating. A gentler exfoliator that also hydrates as it works. Good entry point if you have sensitive skin and want to try acids.
Cited research
Liu H et al., Topical agents for acne (covers AHA / fruit-acid arm), Cochrane Database of Systematic Reviews 2020;5:CD011368 — conclusion: clinical benefit is unclear
Sarkar R et al., Comparative Evaluation of Efficacy and Tolerability of Glycolic Acid, Salicylic-Mandelic Acid, and Phytic Acid Combination Peels in Melasma, Dermatologic Surgery 2016;42(3):384-391 — 35% glycolic acid and salicylic-mandelic peels equally effective and safe for melasma in Indian skin
Kubiak M et al., Evaluation of 70% glycolic peels versus 15% trichloroacetic peels for the treatment of photodamaged facial skin in aging women, Dermatologic Surgery 2014;40(8):883-891 — both peels improved photodamaged skin; glycolic acid showed faster hydration recovery
CIR Final Report on the Safety Assessment of Glycolic Acid and Lactic Acid, their salts and simple esters (Andersen FA), International Journal of Toxicology 1998;17(Suppl 1):1-241
Stiller MJ et al., Topical 8% glycolic acid and 8% L-lactic acid creams for the treatment of photodamaged skin. A double-blind vehicle-controlled clinical trial, Archives of Dermatology 1996;132(6):631-636 — 76% of glycolic acid users improved at least one grade vs 40% vehicle
Garcia A, Fulton JE Jr, The combination of glycolic acid and hydroquinone or kojic acid for the treatment of melasma and related conditions, Dermatologic Surgery 1996;22(5):443-447 — glycolic acid topical products highly effective in reducing melasma pigment
Fanning N et al., Treatment of mild-to-moderate facial cutaneous aging using a combination peel containing 6% trichloroacetic acid and 12% lactic acid, Journal of Cosmetic Dermatology 2023;22(11):3033-3041 — three monthly peels significantly improved clarity, pigmentation, fine lines, roughness in 32 subjects
Tang SC, Yang JH, Dual effects of alpha-hydroxy acids on the skin, Molecules 2018;23(4):863 — effect concentration-dependent
Babilas P et al., Cosmetic and dermatologic use of alpha hydroxy acids, JDDG: Journal der Deutschen Dermatologischen Gesellschaft 2012 — supports AHAs including lactic acid for photoaging, pigmentation, and barrier effects
Smith WP, Epidermal and dermal effects of topical lactic acid, Journal of the American Academy of Dermatology 1996;35(3 Pt 1):388-91 — 12% lactic acid increased epidermal/dermal firmness and thickness
Rawlings AV et al., Effect of lactic acid isomers on keratinocyte ceramide synthesis, stratum corneum lipid levels and stratum corneum barrier function, Archives of Dermatological Research 1996;288(7):383-390 — foundational: L-lactic acid stimulated keratinocyte ceramide biosynthesis (48% increase) and superior barrier function vs D-isomer
Every entry points to a specific paper or regulatory document. See methodology for what each outcome label means.