In fact, one study found that, when applied to skin, a kojic acid preparation increased skin brightness in 75% of participants. Best Kojic Acid SoapsBest Overall: ​Best Gel Formula: ​Best Bar Soap: ​Best Clarifying Soap: ​Best Multi-Use Option: ​You want to take special care when choosing a kojic acid soap to address your skin's needs because not all are created equal, says Dr. Gohara. How we selectedFor the past few months, Women’s Health editors, I researched the bestselling, most popular, and top-rated kojic acid soaps. Collectively, we then narrowed down the best kojic acid soaps for a wide range of skincare needs and preferences. If you're ready to check out your options, read on for the seven best kojic acid soaps of 2025.