Although it is still a long way off, an injectable male contraceptive is in development. It would join condoms, withdrawal and vasectomies as an option for men to use to prevent their partners from becoming pregnant. Currently, pregnancy prevention methods typically focus on the woman. According to the Guttmacher Institute, 40 percent of all pregnancies in 2012 were unintended.
The injectable male contraceptive – which is a reported 96 percent effective – was developed and tested by a research arm of the World Health Organization and the East Virginia Medical School in the United States. A year-long study was carried out at ten centers in seven countries, including the U.S., Australia, Indonesia, Chile, Germany and India.
News of the experimental drug is being reported in the Journal of Clinical Endocrinology and Metabolism.
Mario Festin, a medical officer with WHO’s Department of Reproductive Health and Research in Geneva, said the male contraceptive trial was what scientists call a proof-of-concept. “This hormonal combination of testosterone with the progestin or any other hormone that could facilitate the sustenance of the low sperm counts can actually lead to a level of sperm count that could be considered as contraceptive. And it could be done.”
The contraceptive drug for men is a combination of the male hormone testosterone, which significantly lowered the sperm count, and progestogen, a hormone in both sexes that in the men sustained the cessation of sperm production.
The drug suppresses the production of sperm to the point where pregnancy is unlikely. It involves a series of injections over several months before the sperm count drops enough to prevent pregnancy. The shots have to be given every two months to remain effective.
In the trial involving 320 healthy men between the ages of 18 and 45, the shots caused a variety of unpleasant side effects because of the high hormone levels required to prevent pregnancy. Those included acne, depression, increased libido and pain at the injection site. Festin said depression and increased libido in particular caused problems among partners.
The WHO’s review board, which monitored how the experiment was going, stopped the trial, but allowed researchers to continue to follow the men. Within one year, almost all of the men’s sperm counts returned to normal.
Festin says the male contraceptive injection has to be tweaked before it can go on the market. “So there are other groups that are studying other hormone combinations or other hormone preparations which more or less follow the same study methodology and the same concept of a testosterone and a progestin.”
Jamin Brambhatt, a urologist at Orlando Health Regional Medical System in Florida, said it’s time for an injectable male contraceptive, like the one that’s just been tested.
“Hopefully that will inspire someone to think of something or get a pharmaceutical company or researchers to think above and beyond and find something because there’s definitely a need. You know ... a majority of the burden right now is on the female. So for us, as guys, to take a small share of that or more of a share of that onto us, I think would definitely help the overall system.”
Despite the side effects, researchers report 75 percent of men in the study said they would continue to use the new male contraceptive.