To provide an excellently safe promoter of hyaluronic acid synthesis or of collagen synthesis, improving productivity of hyaluronic acid or collagen in vivo through the activation of a skin cell without externally imparting the hyaluronic acid or the collagen, as a result, preventing the formation of wrinkles of the skin accompanied with aging, and reducing the initially formed wrinkles of the skin to provide the smooth, moist and fresh skin, and to provide an external preparation for the skin and a food and drink using the promoter.

The external preparation for the skin, and the food and drink using the promoter are obtained by using the promoter of the hyaluronic acid synthesis, the promoter of the collagen synthesis or the like. The external preparation for the skin contains genkwanin represented by formula (I) as an active ingredient. The genkwanin promotes the synthesis of the hyaluronic acid and/or the collagen in the cell by activating a human dermal fibroblast.