PROBLEM TO BE SOLVED: To provide a new testosterone 5&alpha-reductase inhibitor, an androgen receptor binding inhibitor, an antiandrogenic agent, a hair cosmetic, a prostatomegaly inhibitor, and a health supplement. SOLUTION: The above testosterone 5&alpha-reductase inhibitor, androgen receptor binding inhibitor, antiandrogenic agent, hair cosmetic, prostatomegaly inhibitor and health supplement, are each obtained by including the extract from the leaves of Averrhoa carambola L.