Lactic acid (AHA)
Lactic acid is an alpha-hydroxy acid (AHA) used in cosmetic products and professional peels. It is a different material from poly-L-lactic acid (PLLA), the polymer used in some injectable biostimulators. A lactic-acid peel belongs to chemical renewal.
Gentleness depends on the preparation
The ingredient may be discussed in hydrating skincare, but that does not establish that every professional lactic peel is hydrating or milder than another acid. Concentration, pH, other ingredients and the planned application influence exfoliation and tolerability.
Evidence is specific to the concern
A 2025 melasma trial randomized 40 patients and analyzed 34 who completed treatment. Both lactic and glycolic groups improved, with a larger reduction in melasma scores in the tested glycolic group. Reported side effects did not differ significantly. This small trial cannot predict every formula’s performance or establish a permanent cure for melasma.
Plan aftercare with the practitioner
Discuss pigment risk, recent sun exposure and existing skincare. Peels can cause irritation, burns, infection or scars. Ask for a recovery and sun-protection plan for the exact treatment. A daily-use lactic product and a professional peel need their own instructions.
Read the original sources
Sources describe specific products, studies or countries. They do not establish approval everywhere.
General education. Your clinician can assess your individual suitability. Rules depend on the treatment country; FDA references concern the United States. External sources may be in another language.