All three are AHAs — surface exfoliants that smooth texture and brighten. The difference is molecule size, which decides how deep they go and how much they irritate.
Glycolic acid — the strongest
The smallest molecule, so it penetrates deepest and works fastest on texture and dark spots. Also the most likely to irritate — best for resilient, non-sensitive skin.
Lactic acid — the balanced one
A larger molecule, so it’s gentler while still smoothing and hydrating (a bonus for drier skin). A great middle ground and a good first AHA.
Mandelic acid — the gentle one
The largest molecule, so it penetrates slowly and is the most tolerable — ideal for sensitive and acne-prone skin, and for darker skin tones prone to post-inflammatory marks.
How to choose (and not overdo it)
- Tough, oily, resilient skin → glycolic
- Normal/dry, want hydration → lactic
- Sensitive or acne-prone → mandelic
Whichever you pick, a few nights a week is plenty — stacking acids is the fastest route to over-exfoliation. Browse exfoliant products and let the routine builder keep them from clashing.