Researchers have tried to develop contraceptives for men that would be like birth control pills for women. Hormone birth control for men has been hard to achieve. Giving sex hormones to men can lower the sperm produced. However, this approach also lowers the male hormone testosterone in the body, so some testosterone has to be 'added back.' This review looks at the randomized controlled trials of giving hormones to men to prevent their sexual partners from becoming pregnant.
We did a computer search for studies of hormones tested for contraception in men. We also looked at reference lists of articles. We included randomized controlled trials in any language. We wrote to trial authors to find other studies we may have missed.
We found 33 studies. The main focus of the trials was having no sperm found in semen. The percent of men who achieved no sperm varied widely. We found a few major differences and list them as follows: 1) implants plus injected testosterone worked better than a pill plus testosterone patch; 2) adding a hormone pill improved the effect of testosterone injected weekly; 3) a hormone pill also improved the effect of a testosterone injection with more injections at 6 and 12 weeks; 4) a lower dose pill did not work as well as a higher dose when testosterone was put under the skin (implant); 5) when used with implants, a lower dose of injected testosterone led to no sperm more often than a higher dose; 6) an injected hormone plus injected testosterone led to no sperm more often when given every 8 weeks versus 12 weeks; 7) four implants of a male hormone worked better than two implants.
Several trials showed good results for percents with no sperm. Five trials studied testosterone and another hormone. The other hormones were desogestrel, etonogestrel, and levonorgestrel.
No hormonal birth control for men is ready for general use. Most trials were small pilot studies trying out different hormone treatments. Larger trials with better methods are needed to test good leads in this area.