The Phase 2b study involved 222 men who took a daily gel for at least three weeks made from the progestin drug segesterone acetate and testosterone, a compound developed by the Population Council, a nonprofit organization focused on reproductive health, in collaboration with the National Institutes of Health.
In the trial, researchers performed sperm count tests every four weeks to assess sperm suppression. To be effective at preventing pregnancy, people should aim for a sperm count of less than one million sperm per milliliter. A normal sperm count is between 15 and 200 million sperm per milliliter of semen. By the 15th week, 86 percent of participants had achieved this low baseline, and sperm production was typically suppressed by the eighth week of treatment.
Diana Bliss, director of the National Institutes of Health’s contraceptive development program, said the findings were groundbreaking and that she believes male contraception is a men’s health issue as well as a women’s health issue.
Bliss said the women who participated in the clinical trial with their partners were relieved to be able to stop using hormonal contraception for the duration of the study.
“A lot of women have challenges with different methods of contraception, so what was eye-opening about the clinical trial was listening to these women’s stories and hearing what it meant to them to be part of the study, especially when they were able to go off birth control for a year,” Bliss said.
For men, the only effective commercially available contraception is vasectomy, which is not easily reversible, and condoms, which are not widely used.
Here’s what you need to know about the gels being studied and the current state of male contraception research.
