Soy sauce, sake, and skincare all have one thing in common — Kojic Acid.
Kojic acid, a by-product of soy sauce and sake production, is currently a debated skincare ingredient due to potential contact dermatitis, an uncomfortable rash, when used on sensitive skin.
Chemists at the University of Pretoria in South Africa are studying the benefits of kojic acid in skincare. Their research has shown recent developments in kojic acid’s effectiveness and safety.
Due to various beauty influencers on platforms like Tiktok, Instagram, and Youtube celebrating kojic acid as a miracle whitening product, it is important to understand the true abilities and downfalls of this ingredient.
Hyperpigmentation can be treated through the use of kojic acid (Credit: Büşranur Aydın, Pexels)
This ingredient is highly sought after due to its skin-whitening properties. Particularly, the acid is being used to spot treat facial hyperpigmentation from sun spots and acne scars.
Kojic acid’s skin whitening features are derived from its ability to inhibit tyrosinase, the enzyme needed to produce the skin pigment melanin. While kojic acid should not be used to lighten overall skin complexion, its “mild antioxidant, antimicrobial, and exfoliating properties,” according to Board-Certified Dermatologist Dr. Jennifer MacGregor, makes it suitable for small-scale skin lightening.
Chemical structure of Kojic Acid (Credit: Fuzzform, Wikimedia Commons)
Despite its generally mild properties, kojic acid should still be used with caution. Prolonged use may increase sensitivity to sun exposure and dermatitis for those with sensitive skin. Discoveries from the mentioned study suggest against using kojic acid at concentrations that exceed 1%. At this concentration, there is a greater risk for contact dermatitis.
Popular skincare brands are saturating the market with kojic acid. The compound can be combined with other well-known ingredients, such as vitamin C, glycolic acid, niacinamide, and hydroquinone.
Depending on the additional ingredients, kojic acid can be diluted to be tolerable for sensitive skin or compounded to accelerate whitening abilities.
Kojic acid can currently be found in various forms to suit consumer preferences. Currently, the most sought-after forms of kojic acid are SkinCeuticals’ Discoloration Defense serum, Koji White’s Kojic Acid Skin Brightening Soap, and Versed Skin’s Weekend Glow Daily Brightening Facial Toner.
As more research is done to understand the properties of kojic acid, beauty and skincare communities are likely to see a rise in the acid’s popularity. Consumers must continue to be vigilant to ensure they are using safe concentrations for their skin conditions.
-Carissa Chua