It is intended to provide a hair growth promoting agent, hair regrowth promoting agent or therapeutic for alopecia by determining an endogenous factor that inhibits hair growth and screening for substances that inhibit the activity or expression of the endogenous factor. It has been found that FGF18 inhibits hair growth. A method of screening for substances that inhibit the activity of FGF18 or substances that inhibit the expression of FGF18 to thereby obtain candidates for the hair growth promoting agent, hair regrowth promoting agent or therapeutic for alopecia is disclosed. Also disclosed is a hair growth promoting agent, hair regrowth promoting agent or therapeutic for alopecia comprising, as an active ingredient(s), a substance that inhibit the activity of FGF18 and/or a substance that inhibits the expression of FGF18 such as a partial peptide of FGF18 or a Momordica charantia hot water extract.
