Ingredient Guide
Lactic Acid
Also known as: Lactic Acid, L-Lactic Acid, AHA (Lactic)
All skin types (gentler than glycolic acid)
What It Is
An alpha-hydroxy acid (AHA) naturally found in milk and fermented foods. Used in skincare as a chemical exfoliant and NMF humectant.
What It Does
At active concentrations (5–10%+): exfoliates the skin's surface, improving texture and tone. At low concentrations: acts as a humectant and pH adjuster.
Best For
Gentle exfoliationHydration (low concentrations)Sensitive skin AHA option
Benefits
- Gentler than glycolic acid — larger molecule, slower penetration
- NMF humectant at low concentrations
- Improves texture, tone, and radiance
- Better tolerated by sensitive skin than glycolic acid
When to Be Careful
- Increases photosensitivity — SPF is mandatory
- Can still cause irritation at higher concentrations on sensitive skin
Commonly Found In
Exfoliating tonersAHA serumsGentle exfoliantspH-adjusted formulas
Products Containing Lactic Acid
FAQs About Lactic Acid
Is lactic acid gentler than glycolic acid?
Generally yes — lactic acid has a larger molecular size that means it penetrates the skin more slowly, making it better tolerated by sensitive skin. Results are comparable for most concerns, just slightly less aggressive.
Does lactic acid need SPF?
Yes — like all AHAs, lactic acid increases photosensitivity. Daily SPF 30+ is required when using lactic acid regularly.