To provide a novel medicine that is capable of promoting cholesterol metabolism to thereby treat, ameliorate or prevent various symptoms associated with increase in blood cholesterol level. The present inventors newly found that arctigenin has an effect of promoting the conversion of cholesterol into bile acid. The present invention provides a bile acid synthesis promoter, a composition for promoting bile acid synthesis and a food composition for promoting bile acid synthesis each comprising arctigenin and/or arctiin as active ingredient(s).本發明之課題係提供可促進膽固醇代謝，且可治療、改善或預防伴隨血中之膽固醇增加的各式各樣的症狀之新穎藥劑。 解決手段為本發明者等新發現牛蒡苷元具有促進自膽固醇至膽汁酸的轉換的效果。本發明提供一種膽汁酸合成促進劑、膽汁酸合成促進用組成物及膽汁酸合成促進用食品組成物，其含有作為有效成分之牛蒡苷元及/或牛蒡苷。
