The study, a phase 2b trial, included 222 men who completed at least three weeks of daily treatment with a gel made from the progestin drug progesterone acetate and testosterone. The composite was developed by the Population Council, a nonprofit organization focused on reproductive health, in partnership with the National Institutes of Health.
In the trial, researchers conducted sperm count tests every four weeks to assess sperm suppression. They aim for a sperm count of 1 million or less per milliliter for effective contraception. Normal sperm count ranges from 15 million to 200 million per milliliter of semen. At week 15, 86 percent of participants reached the lower threshold, and sperm production was generally suppressed by the eighth week of treatment.
Diana Blyth, head of the National Institutes of Health’s Contraception Development Program, said the findings mark a milestone, adding that male contraception is considered a women’s health issue.
Blyth said women who participated in clinical trials with their partners were relieved when they were able to stop using hormonal birth control for the duration of the study.
“There are a lot of women who struggle with different birth control methods, and an eye-opening aspect of the clinical trial was listening to the women and what it meant to them to be in the study, especially when they were able to stop using their birth control for a year,” Blith said.
The only effective forms of contraception on the market for men are vasectomies, which are not easily reversible and condoms have a low acceptance rate.
Here’s what to know about the studied gel and the state of research on male contraception.
