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Chemical peels

Also known as: glycolic acid peel, salicylic acid peel, TCA peel, chemexfoliation

Chemical peels apply an acid solution to remove controlled layers of skin, from surface-only superficial peels (glycolic, salicylic, mandelic) to medium-depth TCA peels. They are among the oldest procedures in dermatology and have decent trial support for acne and melasma, with glycolic acid the best studied. The main honest caveat is durability: pigment conditions like melasma recur at high rates once peeling stops, and superficial peels do little for actual wrinkles despite frequent anti-aging peel marketing.

How it works

Acids break the bonds holding dead skin cells together and, at higher concentrations, injure living epidermis and upper dermis in a controlled way. The skin rebuilds with more even pigment distribution and, for deeper peels, some new collagen. Salicylic acid is oil-soluble, so it also penetrates and clears pores, which is why it suits acne.

What the evidence says, claim by claim

These are the results measured in studies, not the results shown in ads. Where the research is weak, the grade says so.

For melasma

Moderate evidence

A 2024 systematic review of 24 studies (15 RCTs, 1,075 patients) found peels safe and effective for melasma, with glycolic acid showing the best balance of efficacy and tolerability and outperforming TCA on severity scores. A 2020 meta-analysis in dark-skinned patients supports peels as an adjunct to sunscreen and topical lighteners rather than a standalone cure. Recurrence is the weak point: one series in darker skin reported about 70 percent recurrence by week 12 after stopping treatment.

Randomized trials support this use, but they are few, small, or short. The effect is probably real. The size of it is less certain.

For acne

Moderate evidence

A systematic review of 12 RCTs found commonly used peels (glycolic, salicylic, Jessner's) are similarly effective and well tolerated for mild to moderate acne, though trial heterogeneity blocked pooling. A 2022 network meta-analysis estimated chemical peels produce roughly 40 percent effectiveness for mild to moderate acne, real but below oral and combination topical therapy. Peels are an adjunct to medical acne treatment, not a replacement.

Randomized trials support this use, but they are few, small, or short. The effect is probably real. The size of it is less certain.

For dark spots and hyperpigmentation

Limited evidence

For post-inflammatory hyperpigmentation and general uneven tone, evidence comes mostly from small comparative trials and narrative reviews rather than large RCTs. A 2026 review of peels for pigmentary disorders supports superficial peels as a reasonable option, but in darker skin types the peel itself can trigger new post-inflammatory pigment if depth or aftercare goes wrong, so gains are incremental and technique-dependent.

Only small, short, or lower-quality studies exist. Treat marketing claims about this use with caution.

Risks and what can go wrong

Superficial peels: 1 to 7 days of redness, flaking, and stinging; medium TCA peels: about a week of visible peeling and downtime. Risks include post-inflammatory hyperpigmentation (highest in Fitzpatrick IV to VI, where lower concentrations and test spots are standard practice), herpes reactivation, and with deeper peels scarring. Avoid on active infection, recent isotretinoin per prescriber guidance, open wounds, and during heavy sun exposure periods; strict sunscreen use afterward is non-negotiable.

The practical details

Superficial peels are done in series, typically 4 to 6 sessions 2 to 4 weeks apart, at roughly 150 to 400 dollars per session in the US. Medium-depth peels are single sessions repeated every 6 to 12 months at 500 dollars or more. In-office for anything beyond low-strength at-home acids; results for pigment need maintenance.

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