The Receipt
- 01A supporting player with a thin paper trail. Sunscreen still does the heavy lifting.
Education, not a diagnosis. If something changes quickly, hurts, bleeds, or worries you, see a dermatologist.
Ingredient Receipt · Tone & dark spots
Kojic acid
INCI: Kojic Acid, Kojic Dipalmitate
Kojic acid is a fungus-derived tyrosinase inhibitor found in “brightening” soaps and serums. Evidence, irritation risk and how it compares to other options.
- Dark marks & tone
01 · In plain English
Kojic acid soaps are among the most-searched dark-spot products. The evidence is weaker than the marketing.
02 · What it does
Kojic acid comes from fungi used in fermentation (for example in making sake). It inhibits tyrosinase, the enzyme that drives melanin production.
Most clinical data come from small studies, often combining it with other ingredients, which makes its individual effect hard to judge. It’s also a known cause of contact dermatitis for some people.
03 · Who it’s for
- Uneven tone or post-inflammatory marks, as a supporting step.
04 · What the evidence says
- Modest lightening of hyperpigmentation, usually in combination products.limited evidence
05 · Myths, checked
“Kojic soap works like a peel.”
A wash-off soap has very limited contact time, and drying soaps can irritate, which can worsen marks.
insufficient evidence
06 · Insufficient evidence
- Kojic acid alone matching hydroquinone or azelaic acid.
07 · How to use it
- Leave-on products are more likely to do something than soaps.
- Patch test first, and use daily sunscreen.
08 · Pairs well / go carefully
Pairs well with
- Niacinamide, azelaic acid, sunscreen.
Go carefully with
- Other irritating actives at the same time on sensitive skin.