Lactic acid in skincare: one of the gentler AHAs

Reviewed October 16, 2026

The short answer

Lactic acid is an alpha hydroxy acid (AHA) used in skincare to smooth rough texture. Cleveland Clinic describes it as one of the gentler AHAs - it acts as both an exfoliant and a moisturizer - and lists it as especially good for sensitive skin. Gentle is relative: an acid can still irritate, so the formula and your own skin decide.

What is it?

Lactic acid is an AHA, a family of acids used to exfoliate the skin's surface. On a US label it appears as Lactic Acid, and it shows up in leave-on products and rinse-off products at different strengths.

What did the safety review conclude?

In 1998 the CIR expert panel concluded that glycolic and lactic acid, their common salts and their simple esters, are safe for use in cosmetic products at concentrations of 10% or less, at a final formulation pH of 3.5 or higher, when formulated to avoid increasing sun sensitivity or when directions for use include the daily use of sun protection. CIR re-reviewed the ingredient in December 2013 and did not reopen or change that conclusion. CIR's review covers consumer and salon products, not medical use. This is a safety conclusion, not a promise of results.

What Cleveland Clinic notes

Cleveland Clinic's facial-acids guide calls lactic acid one of the gentler AHAs and a good choice for sensitive skin, acting as both an exfoliant and a moisturizer. It notes that one of its most common uses is to help with keratosis pilaris - painless bumps caused by a buildup of dead skin around hair follicles.

How to read it on a label

US cosmetic labels generally list ingredients in descending order of amount, but anything at 1% or less can appear in any order after those above 1%. Its position does not tell you the exact concentration. Judge the whole product, how it feels on your skin, and what changes when you add or drop it.

What not to conclude

This page does not say lactic acid will fix a skin condition or suit sensitive skin in every product. The CIR conclusion is about cosmetic safety within concentration and pH limits, and it assumes the formula is made to avoid increasing sun sensitivity or directs daily sun protection - so treat sun protection as part of using an AHA. The AAD recommends that you test a new product on a small area of skin, twice daily for 7 to 10 days, before full use.