Testosterone Shows Promise as a Male Contraceptive

Weekly injections of the hormone testosterone can reduce sperm counts to zero in 98.6% of men, providing the first effective male contraceptive, according to a report from a World Health Organization team in the April issue of Fertility and Sterility. That effectiveness is equal to the efficacy of oral contraceptives for women. Boosting the body’s natural levels of testosterone sends a biochemical message to the pituitary gland that blocks the production of two key hormones that normally stimulate the testes to produce both testosterone and sperm. This blockage in turn inhibits sperm release.

The team is now seeking new ways to administer the hormone, such as with longer-term injections or a skin patch. Locally, the technique is being studied by Dr. Ronald S. Swerdloff and his colleagues at Harbor-UCLA Medical Center.