Male contraceptives seem to have been on the horizon for years, but an upcoming clinical trial is the largest and perhaps most promising study into the issue so far.
Researchers from the National Institute of Child Health and Human Development, part of the US National Institutes of Health, have developed a topical gel that could temporarily prevent the production of sperm. MIT Technology Review reports the gel will undergo a four-year clinical trial, starting in April 2018, that involves over 400 couples from across the globe.
So, how does it work? Well, first of all, you don’t rub it on your genitals. All you have to do is rub in half a teaspoon of gel onto your upper arms and shoulders every day.
The gel contains the two hormones progestin and testosterone. The progestin acts to stop the testes from producing enough testosterone to make normal levels of sperm. The testosterone is there to stop any other hormone imbalances. In theory, an application of this combo can suppress sperm levels for up to 72 hours.
“I am very confident that if men put the gel on every day and apply it correctly, it will be effective,” lead investigator Dr Stephanie Page, a professor of medicine at the University of Washington, told MIT Technology Review.
The National Institute of Child Health and Human Development have previously trialed a pair of hormone-based gels during a six-month study in 2012. In this trial, they successfully reduced the male's sperm concentration by 89 percent for a temporary period with minimal adverse effects.
A contraceptive gel was part of a study on rhesus monkeys earlier this year that proved to be 100 percent successful as a long-term male contraceptive. However, this was a totally different method that blocked the testicles' sperm-carrying tubes with a soft gel barrier.
Clinical trials, regardless of success, are one thing. Getting these things into the market is quite another. The development of male contraceptives has been held back for decades for numerous scientific and social reasons. For one thing, one study found that only 25 percent of men would consider using a hormonal contraceptive. They note that substantially more may consider it, but that "it's probably an overestimate of the number of potential users when such a method becomes available."
For another study, 20 out of 320 men incurred serious side effects of a certain contraceptive hormone treatment, so the study was discontinued after a panel of reviewers concluded the risks were too great. Birth control pills that females take also carry risks, such as deep vein thrombosis, depression, and mood changes.
Perhaps though, with the right results and funding, this seemingly straight-forward gel could be the one to break the mold.