title: Male hormonal contraceptives.
abstract: Efforts are underway to develop additional forms of contraception for men. The most promising approach to male contraceptive development involves the administration of exogenous testosterone (T). When administered to a man, T functions as a contraceptive by suppressing the secretion of luteinizing hormone and follicle-stimulating hormone from the pituitary, thereby depriving the testes of the signals required for spermatogenesis. After 2-3 months of treatment, low levels of these gonadotropins lead to markedly decreased sperm counts and effective contraception in a majority of men. Hormonal contraception with exogenous T has proven to be free from serious adverse effects and is well tolerated by men. In addition, sperm counts uniformly normalize when the exogenous T is discontinued. Thus, male hormonal is safe, effective and reversible; however, spermatogenesis is not suppressed to zero in all men, meaning that some diminished potential for fertility persists. Because of this recent studies have combined T with progestogens and/or gonadotropin-releasing antagonists to further suppress pituitary gonadotropins and optimize contraceptive efficacy. Current combinations of T and progestogens completely suppress spermatogenesis without severe side effects in 80-90% of men, with significant suppression in the remainder of individuals. Recent trials with newer, long-acting forms of injectable T, which can be administered every 8 weeks, combined with progestogens, administered either orally or by long-acting implant, have yielded promising results and may soon result in the marketing of a safe, reversible and effective hormonal contraceptive for men.
authors.affiliation: Center for Research in Reproduction and Contraception, Department of Medicine, University of Washington, Seattle, WA 98195, USA. jamory@u.washington.edu
authors.forename: J K
authors.initials: JK
authors.lastname: Amory
mesh_terms: D003272:Contraceptive Agents, Male / Q000494:pharmacology*; D003278:Contraceptives, Oral, Hormonal / Q000494:pharmacology*; D006801:Humans; D008297:Male; D013091:Spermatogenesis / Q000187:drug effects
chemical_list: D003272:Contraceptive Agents, Male; D003278:Contraceptives, Oral, Hormonal