Finally, an effective method of birth control for men may be on its way. Hormonal male contraceptive regimen effectively and reversibly suppresses sperm production.
Male hormonal contraception exploits the hormone feedback loop to suppress sperm production by reducing the release of hormones from the pituitary gland that act on the testes. The method require the administration of testosterone or a derivative androgen to suppress the pituitary hormones called gonadotrophins, and in turn sperm production, whilst ensuring broadly physiological androgen action so as to maintain virilization.
Researchers from China studied 1,045 healthy fertile Chinese men to assess the efficacy, safety and feasibility of testosterone injection as a hormonal male contraceptive. The participants were between 20 and 45 years of age who had already fathered at least one child in the past 2 years of the study. Their female partners were 18 to 38 years old and had normal fertility. All the participants were given testosterone 500 mg injections monthly for 30 months.
During the first 6 months, the men were tested to make sure that the injections had been effective in eliminating or markedly reducing the sperm levels in their semen. Only men with little or no sperm were allowed to continue into next 24 months of the study.
During the follow-up period, nine pregnancies occurred, which translates into a contraceptive failure rate of roughly 1 per 100 men. This rate was excellent compared with other contraceptive methods, including condoms and birth control pills. No serious side effects were noted and after stopping the shots; sperm-making ability returned to normal in all but two men.
This male hormonal contraceptive regimen may offer a novel and workable alternative to existing family planning options for couples who cannot or prefer not to use only female-oriented contraception throughout their reproductive years.
The researchers found that monthly injections of testosterone are a safe, effective, reversible, and reliable means of contraception for men. However, the long-term effectiveness and safety of this treatment still needs to be established.