The role of androgen metabolism and individual androgen metabolites in rat pituitary gland and hypothalamus is discussed on the basis of published data and results of our experiments. It is proposed that metabolism of androgens in these structures is aimed at the formation of not only true sex steroids estradiol-17 beta and 5 alpha-dihydrotestosterone, but also of androgens contributing to the regulation of cell processes, i.e. represents modification (transformation) of androgen signal (testosterone) in target pituitary and hypothalamic cells.