Glycolic Acid vs Lactic Acid
Glycolic Acid vs Lactic Acid — two of the most common alpha hydroxy acids, both water-soluble exfoliants, where glycolic acid has the smallest molecule and penetrates most deeply, while lactic acid is larger, milder, and also mildly hydrating. Glycolic tends to deliver stronger resurfacing, whereas lactic acid is often preferred for gentler exfoliation.
Key points
- Glycolic acid is the smallest AHA, allowing deeper penetration and more potent smoothing and brightening effects.
- Lactic acid has a larger molecule that exfoliates more gently and also offers some humectant, hydrating benefit.
- Lactic acid is often recommended for drier or more sensitive skin, while glycolic acid suits those seeking stronger resurfacing.
- Both are AHAs that increase sun sensitivity, so daily sunscreen is important when using either.
Frequently asked
Is glycolic acid stronger than lactic acid?
Yes, glycolic acid has a smaller molecule and penetrates more deeply, so it is generally more potent, while lactic acid exfoliates more gently.
Which is better for sensitive skin?
Lactic acid is usually the better starting point for sensitive or dry skin because it is milder and has added hydrating properties.
Related topics
This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.
