A molecule produced by fungi during fermentation, used in skincare for its effect on the look of uneven pigmentation.
How it works
Research associates kojic acid with inhibition of tyrosinase, the enzyme that catalyses melanin production. Applied consistently, that is the basis of its association with a more even-looking skin tone. It is the free-acid form — more active, and somewhat less stable, than its ester kojic dipalmitate.
Sensitivity
Can sting on compromised skin, and sensitisation with long continuous use is reported occasionally; cycled use and patch testing are sensible.
Pregnancy and breastfeeding
Evidence is limited; at cosmetic levels the conventional advice is to check with your doctor.
