Kojic Acid

Kojic Acid

AKA “501-30-4, 5-Hydroxy-2-(hydroxymethyl)-4H-pyran-4-one, 5-Hydroxy-2-(hydroxymethyl)-4-pyrone, 5-hydroxy-2-(hydroxymethyl)pyran-4-one, 4H-PYRAN-4-ONE, 5-HYDROXY-2-(HYDROXYMETHYL)-, 5-Hydroxy-2-hydroxymethyl-4-pyrone, acido kojico, 2-Hydroxymethyl-5-hydroxy-gamma-pyrone, 2-(Hydroxymethyl)-5-hydroxy-4H-pyran-4-one”

Acid

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Ingredient Facts

Kojic acid

AKA: 501-30-4, 5-Hydroxy-2-(hydroxymethyl)-4H-pyran-4-one, 5-Hydroxy-2-(hydroxymethyl)-4-pyrone, 5-hydroxy-2-(hydroxymethyl)pyran-4-one, 4H-PYRAN-4-ONE, 5-HYDROXY-2-(HYDROXYMETHYL)-, 5-Hydroxy-2-hydroxymethyl-4-pyrone, Acido kojico, 2-Hydroxymethyl-5-hydroxy-gamma-pyrone, 2-(Hydroxymethyl)-5-hydroxy-4H-pyran-4-one

Acid · Antioxidant · EWG: 7

Synthetic

Antioxidant

Ferment

Acid

Not Clean

5-Hydroxy-2-hydroxymethyl-4-pyrone

Solubility Soluble in ethanol, ethyl ether, acetone, DMSO; slightly soluble in benzene

Formula

C6H6O4

Mol. Weight

142.11

CAS #

501-30-4

Form

Liquid

State

Solid

See origin →

Functions

Antioxidant

Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.

Evens pigmentation

Brightens uneven skin tone

Traditional Use

Kojic acid was discovered in 1912 as a byproduct of sake (Japanese rice wine) fermentation. It has been used since the 1960s in East Asian skincare, particularly Japan, as a skin-brightening and tyrosinase-inhibiting agent for treating hyperpigmentation.