Is lactic acid the same as glycolic acid?

Both are alpha hydroxy acids (AHAs) used to exfoliate, but lactic acid is larger and generally gentler than glycolic acid. Lactic acid is often better tolerated for people starting with AHAs, though both can cause stinging or increased sun sensitivity at higher concentrations.

Do I need to use SPF when using lactic acid?

Yes, daytime SPF is sensible when using lactic acid regularly, since AHAs can increase sun sensitivity. Consistent sun protection helps reduce the risk of irritation and photosensitivity while exfoliating.

Can lactic acid irritate sensitive skin?

Lactic acid can cause stinging or increased sensitivity, especially at higher concentrations or lower pH. If you have reactive skin, start with low-concentration products or use less frequently, and discontinue if irritation persists.

exfoliant · humectant · ph-adjuster

Lactic Acid

Watch if sensitive·Strong evidence

A larger, gentler alpha hydroxy acid than glycolic acid, used to exfoliate and to draw in moisture. It can still cause stinging or increased sun sensitivity at higher concentrations, so daytime SPF use is sensible, but it is generally better tolerated than glycolic acid.

Worth knowing

Can irritate, especially left on
Restricted in the EU

Regulated similarly to other AHAs under EU rules on free acid content and required sun-sensitivity labeling.

Questions

Is lactic acid the same as glycolic acid?: Both are alpha hydroxy acids (AHAs) used to exfoliate, but lactic acid is larger and generally gentler than glycolic acid. Lactic acid is often better tolerated for people starting with AHAs, though both can cause stinging or increased sun sensitivity at higher concentrations.
Do I need to use SPF when using lactic acid?: Yes, daytime SPF is sensible when using lactic acid regularly, since AHAs can increase sun sensitivity. Consistent sun protection helps reduce the risk of irritation and photosensitivity while exfoliating.
Can lactic acid irritate sensitive skin?: Lactic acid can cause stinging or increased sensitivity, especially at higher concentrations or lower pH. If you have reactive skin, start with low-concentration products or use less frequently, and discontinue if irritation persists.

Products with Lactic Acid

In our guides

References

This dossier covers safety and concern. For what the efficacy evidence says about Lactic Acid, see SerumTruth ↗, our sister site.

Cosmetic information for general education, not medical advice. A verdict is a reading of the published evidence, never a guarantee for your skin: any ingredient can irritate someone, so patch test new products and see a professional if you react. Concern is graded on cited evidence, never on hazard-score lists. See how we score.