Enhanced Whitening Effect of the Formulations via Inhibition of Tyrosinase Activity by Combination of 4‐ <i>n</i> ‐Butylresorcinol, Licochalcone A and Glabridin at an Optimal Ratio

The 5:1:1 molar ratio of 4-n-butylresorcinol, licochalcone A, and glabridin was the best ratio that could inhibit both tyrosinase activity and melanin content. The formulation containing this ratio combination can enhance the skin whitening efficacy and also can prevent the UV and blue light induced skin pigmentation.