Lexikon

any steroid hormone that promotes male secondary sex characters. The two main androgens are androsterone and testosterone. Called also androgenic hormone.  

The androgenic hormones are internal endocrine secretions circulating in the bloodstream and manufactured mainly by the testes under stimulation from the pituitary gland. To a lesser extent, androgens are produced by the adrenal glands in both sexes, as well as by the ovaries in women. Thus women normally have a small percentage of male hormones, in the same way that men's bodies contain some female sex hormones, the estrogens. Male secondary sex characters include growth of the beard and deepening of the voice at puberty. Androgens also stimulate the growth of muscle and bones throughout the body and thus account in part for the greater strength and size of men as compared to women.

Source: medical-dictionary.thefreedictionary.com/Anti-androgen