The safety and efficacy of a male contraceptive gel, developed by the Population Council and the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), will be evaluated in a clinical trial to determine its ability to prevent pregnancy.

The year-long Phase 2b trial, funded by the National Institutes of Health, will enroll approximately 420 couples that are seeking pregnancy prevention across 3 US sites (Los Angeles, Seattle, and Kansas City). Future trial sites will include Chile, England, Italy, Kenya, Scotland, and Sweden.  

The NES/T gel is composed of Nestorone (segesterone acetate), a progestin hormone used for female contraception, and testosterone. The transparent gel is intended to be absorbed through the skin on the upper arms and shoulders and works by reducing sperm production while maintaining normal sex drive. The trial will also examine the acceptability of the daily gel as a contraceptive method among the study couples. 

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In the study, men will apply the gel once daily until sperm counts reach an appropriate level sufficient for contraception, which is anticipated to take 8 to 16 weeks. At this point, the couple will use the gel as their only form of contraception for 1 year. During this time, sperm count will be regularly monitored to help minimize the chance of pregnancy. Males will be followed-up for another 24 weeks after discontinuing the gel. 

“We have been developing this product for more than a decade,” said Diana Blithe, PhD, chief of NICHD’s Contraceptive Development Program and director of the Contraceptive Clinical Trials Network. “We are hopeful that the NES/T gel study will demonstrate effectiveness of a male method for use by couples. A successful result may lead to additional scientific discovery around contraceptive products for men.” 

Data from the clinical trial are expected in 2022 and will determine if the gel will be evaluated in a larger-scale Phase 3 contraceptive efficacy trial. 

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