PROBLEM TO BE SOLVED: To provide a melanogenesis inhibitor excellent in skin-whitening effect and safety.SOLUTION: The melanogenesis inhibitor comprises hydrogenated costunolide represented by the general formula (1) as an active ingredient. (In the formula, a broken line part represents a single bond or a double bond.)COPYRIGHT: (C)2014,JPO&INPIT【課題】本発明は、美白効果と安全性に優れたメラニン生成抑制剤の提供。【解決手段】下記一般式(1)で示される水素添加コスツノライドを有効成分とするメラニン生成抑制剤。(式中、破線部は単結合又は二重結合を示す。)【選択図】なし