A male contraceptive is a device or a drug used by a man that prevents conception in his female partner. The only methods of contraception currently available to men are withdrawal, condoms, and vasectomy. Withdrawal and condoms can be inconvenient, and both suffer from unreliability in typical use. Vasectomies are reliable and have a high satisfaction rate, but are not readily reversible (vasovasostomy).
New male contraceptives — which promise to be safe, reliable, reversible, and convenient — are in various stages of research and development. These new contraceptives take many different approaches toward contraception:
- Prevention of the formation of new sperm by blocking hormones or small molecules needed in the testes. This is how a male hormonal contraceptive, the analogue of the "the Pill" for women, works. It is also how various heat treatments and lonidamine analog compounds work. Because spermatogenesis takes about 72 days, methods of male contraception that act on the testes take about that long to become effective.
- Interference with the maturation of sperm in the epididymis, which is the long, coiled tube through which sperm pass after exiting the testes. This approach is considered the most promising by the major pharmaceutical companies working in this field. Drugs targeting this phase of sperm development would become effective faster. Two pharmaceuticals are testing small, easily synthesized drug compound candidates.
- Partially or completely blocking the vas deferens, the tubes connecting the epididymis to the urethra. While a vasectomy removes a piece of each vas deferens, RISUG, the intra vas device (IVD) and injectable plugs only block the tubes until the devices are removed.
- Other new male contraceptives act once the sperm have entered the female reproductive tract. Some interfere with the sperm's ability to swim properly, while others prevent sperm from recognizing or binding to an egg. Zaveca, Dr. Joseph Hall's enzyme inhibitor, and calcium channel blocker drugs all work this way.
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