Last week, the first worldwide clinical trial of a male contraceptive gel launched in the US. Funded by the US’s National Institutes of Health, it will go on to include 420 couples in various locations around the world, including Chile, England and Sweden.
The male birth control gel has been in development for close to a decade, with researchers making refinements from the findings of small-scale tests since 2009.
“We’ve had over 200 men exposed to the medication, and we’ve never had any serious adverse events,” Christina Wang, a researcher at the Los Angeles Biomedical Research Institute and principal investigator of the trial, told Gizmodo. “But we will be monitoring everything very closely.”
The gel combines Nestorone, a type of progestin used in many female contraceptives, and testosterone. In men, progestin acts as contraceptive by suppressing sperm count — however, it also causes testosterone levels to drop, too. Testosterone is the male reproductive hormone essential to a host of healthy functions in men, and its inclusion as an ingredient in the gel is meant to prevent undesirable side effects, such as acne, weight gain and low sex drive, which could result from progestin-only treatment.
The trial will require men use the gel for 20 weeks, simultaneously with another form of birth control. After roughly 20 weeks of daily application to their chest and shoulders, the participants’ sperm counts should have declined to levels so low as to be considered infertility. For the next year, the men, as well as their female partners, will use the gel as their only form of birth control. Following that year, the men will discontinue using the gel, and the research team will track their health for six months, to make sure sperm count resumes normal, healthy levels. Ultimately, the trial will conclude by 2022, and if the findings are positive, will still face many more hurdles and trials before gaining approval by the US’s Food and Drug Administration.
Throughout the study, the researchers will monitor not only men’s sperm count and general health, but also the satisfaction of the couple — the men in the study and their female partners — with the gel as a form of birth control.
It’s not the first clinical trial of a male contraceptive, but it is the first large-scale clinical trial of a male birth control medication since a clinical trial of a male contraceptive shot was shuttered ahead of schedule in 2016 out of concern over the severity of participants’ side effects.
