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Kojic acid

Ingredient · In our Dark Spot Treatment

Kojic acid

Kojic acid is a brightener first found in koji, the mold (Aspergillus oryzae) used to ferment rice for sake and soy sauce. It works by slowing an enzyme skin needs to make pigment.1

Golden stalk of rice in a sunlit field
Rice

Photo shows a rice stalk, a nod to koji fermentation. The kojic acid in our cream is made in a lab.

Early evidence

Kojic acid isn't an FDA-approved drug for dark spots. The best human study is small and tested it alongside other brighteners.1 Our creams are compounded by a licensed pharmacy, and compounded versions are not FDA-approved.2

FDA-approved for this useWell studied, used off-labelEarly evidenceLittle or no human data

The studies below used FDA-approved products or other forms. Our compounded version hasn't been studied in trials, and results may differ.

What it is

Kojic acid blocks tyrosinase, an enzyme your pigment cells use to make melanin.1

Why it's in this product

It adds a second way of slowing pigment next to hydroquinone, which is the idea behind combining brighteners in our Dark Spot Treatment.

Dark Spot Treatment

What the studies in people show

  • Randomized trialA boost when added to other brightenersIn 40 women with melasma, each used a hydroquinone and glycolic acid gel on both sides of the face, with kojic acid added on one side. More than half the melasma cleared in 60% of kojic acid sides versus 47.5% without it.1

What we don't know yet

That trial was small and short (12 weeks), and kojic acid wasn't tested on its own. Larger, longer studies are still needed.

Safety, in plain English

In the study above, redness, stinging and peeling happened on both sides of the face and settled by the third week.1 Kojic acid can irritate sensitive skin, so let your clinician know if it does.

A licensed clinician reviews your health history and decides whether this cream is appropriate for you. Exploring it here never means you'll get a prescription.

Curious about kojic acid?

Start with a free assessment. A licensed clinician reviews your health history and decides whether treatment is appropriate. No pressure, and no prescription unless it makes sense for you.

See Dark Spot TreatmentHow care works

Sources

  1. Lim JT. Treatment of melasma using kojic acid in a gel containing hydroquinone and glycolic acid. Dermatol Surg. 1999;25:282-284. PubMed 10417583
  2. U.S. Food and Drug Administration. Compounding and the FDA: Questions and Answers. FDA

Sources checked November 8, 2026. This page is general education, not medical advice, and it doesn't mean any treatment is right for you. Photos: Unsplash (Rejaul Karim).