Ingredient glossary

Mandelic acid

The largest common AHA, so it exfoliates more gradually

AHA · in DuoClear™

Mandelic acid

The largest common AHA. Its bigger molecule exfoliates more gradually, which makes it a good daily partner to salicylic acid in DuoClear™.

1%In DuoClear™

3.41pKa

152g/mol

0.62log P

AHA · C₈H₈O₃ · 152 g/mol · pKa 3.41 · log P 0.62

Two acids, two places: the pore and the surface

Where it works

Mandelic acid is a larger alpha hydroxy acid, so it exfoliates the surface more gradually for smoother, more even-looking skin.

Why two acids?

Skin needs help in two places: inside the pore, where oil and dead cells collect, and on the surface, where rough texture builds up. One acid rarely does both well.

Why low pH matters

An acid only works in its free-acid form. Below its pKa (salicylic 2.97, mandelic 3.41), most of the acid stays active. At a higher pH, more of it turns into a salt. DuoClear™ formulas are kept at a low pH so the acids stay acids.

Found in