Lactic Acid vs Mandelic Acid
Which is right for your skin?
Two of the gentlest AHAs: lactic acid exfoliates while drawing in moisture, so it suits dry skin; mandelic acid's larger molecule works the slowest of all, making it the kindest pick for sensitive skin and deeper skin tones. Dry skin → lactic; easily-irritated skin → mandelic.
A gentler exfoliator that also hydrates as it works. Good entry point if you have sensitive skin and want to try acids.
The slowest, gentlest exfoliating acid. Resurfaces with the least irritation, especially friendly to sensitive and deeper skin tones.
Can you use Lactic Acid and Mandelic Acid together?
Yes — Lactic Acid and Mandelic Acid are documented to pair well together.
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.
You want exfoliating. The slowest, gentlest exfoliating acid. Resurfaces with the least irritation, especially friendly to sensitive and deeper skin tones.
Cited research
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
Ravikumar P et al., Efficacy of Alpha and Beta Hydroxy Acid Chemical Peels in Postacne Pigmentation, Journal of Clinical and Aesthetic Dermatology 2022 — mandelic-acid-containing peels improved postacne hyperpigmentation in a randomized comparison
Dayal S et al., Comparative study of efficacy and safety of 45% mandelic acid versus 30% salicylic acid peels in mild-to-moderate acne vulgaris, Journal of Cosmetic Dermatology 2020 — 45% mandelic acid peels comparably effective and better tolerated than 30% salicylic peels
Sarkar R et al., Comparative study of 35% glycolic acid, 20% salicylic-10% mandelic acid, and phytic acid combination peels in the treatment of active acne, Journal of Cutaneous and Aesthetic Surgery 2019;12(3):158-163
Jacobs SW, Culbertson EJ, Effects of Topical Mandelic Acid Treatment on Facial Skin Viscoelasticity, Facial Plastic Surgery 2018;34(6):651-656 — twice-daily topical mandelic acid for 4 weeks increased lower-eyelid skin elasticity by 25.4%
Kontochristopoulos G, Platsidaki E (Greece), Chemical peels in active acne and acne scars, Clinics in Dermatology 2017;35(2):179-182 — review supporting mandelic-acid-containing peels for active acne and acne scarring
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 — salicylic-mandelic combination peels equally efficacious to 35% glycolic in 90 Indian melasma patients
Every entry points to a specific paper or regulatory document. See methodology for what each outcome label means.