Towards a pill for men
de Kretser, D.M.
Proceedings of the Royal Society of London. Series B Biological Sciences 195(1118): 161-174
1976
ISSN/ISBN: 0950-1193 PMID: 13377 DOI: 10.1098/rspb.1976.0106Document Number: 467165
The prospects for the development of an oral contraceptive for men is outlined. Male fertility may be temporarily interrupted by interference with the hormonal control of the testis, a direct action of agents on spermatogenesis or by interference with the acquisition of fertilizing ability once sperm leave the testis. Spermatogenesis can be suppressed successfully by the antigonadotropic action of androgens, progestagens or estrogens used alone or in combination. The results of these studies provide the basis for the future development of an oral contraceptive. The adjustment of doses to provide adequate spermatogenic suppression without loss of libido is also required. Preliminary studies indicate that compounds which are capable of selectively suppressing SFH levels do exist and may enable spermatogenic suppression without alteration of androgenic function. The majority of substances that act directly on the testis appear to be too toxic to suppress spermatogenesis reversibly. Recent studies with 5-thio-D-glucose have demonstrated inhibition of spermatogenesis which is reversible on ceasing to take the agent. This material appears non-toxic in the doses required and does not alter libido and potency. Interference with the epididymal maturation of sperm is feasible using .alpha.-chlorohydrin but toxic effects have prevented its use in primates. Analogues with similar actions have been identified which cause infertility but toxicity data have not been fully evaluated.