Vaginal contraception with gossypol: a clinical study.

A clinical study concerning the vaginal contraceptive efficacy of gossypol acetic acid was performed. Fifteen women who had undergone tubal sterilization volunteered for the study. The effect of vaginal gossypol-containing gel on spermatozoa was determined by postcoital tests performed in subjects without and after using gossypol gel. After gossypol application, the number of spermatozoa found in cervical mucus was greatly decreased and, in eleven of the fifteen women, all spermatozoa seen were immobilized. In four cases a few poorly motile spermatozoa were seen but they showed no forward progression. We have previously reported that gossypol has an inhibitory effect on herpes simplex virus type 2 in vitro. This anti-viral property of gossypol makes it particularly attractive as a topical barrier contraceptive. The present study shows that gossypol is also promising as a vaginal contraceptive agent in human in vivo experiments.