Kojic Acid

Kojic Acid

AKA “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-4-pyrone, acido kojico, 2-Hydroxymethyl-5-hydroxy-gamma-pyrone, 2-(Hydroxymethyl)-5-hydroxy-4H-pyran-4-one”

Synthetic

Ingredient Facts

Kojic acid

AKA: 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-4-pyrone, Acido kojico, 2-Hydroxymethyl-5-hydroxy-gamma-pyrone, 2-(Hydroxymethyl)-5-hydroxy-4H-pyran-4-one

Synthetic · Antioxidant · EWG: 3

Synthetic

Antioxidant

Skin Conditioner

Ferment

Synthetic

Clean

Kojic acid is a gentle antioxidant that helps protect skin from environmental damage and supports a more even, radiant complexion.

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.

Skin Conditioning

A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.

Depigmenting

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.