Mandelic Acid vs Glycolic Acid: Which Exfoliant Is Right for Your Skin?

If you've stood in front of our exfoliant shelf wondering whether to grab a mandelic serum or a glycolic serum, you're not alone. Both are effective acids, but they work a little differently — and picking the wrong one for your skin type can mean unnecessary irritation instead of results.

The Short Version

Glycolic acid has the smallest molecule of the common AHAs, so it penetrates fastest and works fastest. That makes it excellent for texture, dullness, and clogged pores — but also means it's more likely to cause sensitivity, especially on melanin-rich or reactive skin.

Mandelic acid has a much larger molecule, so it penetrates more slowly and gently. It delivers similar exfoliation and brightening benefits with meaningfully less irritation risk, which is why it's often the safer starting point for acne-prone, sensitive, or deeper skin tones.

Which One Should You Actually Use?

If your main concerns are active acne, hyperpigmentation, or you have sensitive/reactive skin, start with mandelic acid. We carry it in 5%, 8%, and 11% strengths, so you can build up gradually as your skin adjusts.

If your skin already tolerates exfoliants well and your main concern is texture or dullness rather than active breakouts, glycolic acid may work faster. We carry 5% and 10% options.

A Note on Combining Them

You generally don't need both in the same routine, and layering multiple strong acids without guidance is one of the most common ways people accidentally damage their skin barrier. If you're not sure which is right for you, that's exactly what a consultation with Kiki is for — we'll look at your actual skin, not just guess from a product description.

This post is for general education and isn't a substitute for a professional skin consultation. Results vary by individual.