This summer, the Population Council's Nestorone®/Testosterone transdermal gel, a new topical gel that blocks sperm production, will begin a Phase IIb clinical trial. The trial will start in the U.S. before being expanded to Britain, Italy, Sweden, Chile, and Kenya.
Population Council researchers are working with the National Institute of Child Health and Human Development (NICHD) to develop this novel reversible contraceptive for men, which is designed to be applied daily and absorbed through the skin of a man’s shoulders or upper arms.
The men in the study will rub an experimental gel—a blend of a synthetic progestin called Nestorone and a testosterone booster—into their shoulders once a day. Nestorone quells sperm production, while extra testosterone offsets the resultant hormone imbalances. Researchers will then log the NES/T blend’s effectiveness in preventing pregnancy in their female partners.
Although it will take years to reach consumers, early findings are promising: the process appears reversible, side effects minimal and success rates high. To date, family planning has focused largely on women, with male options limited to condoms, which sometimes break, or vasectomies, which cannot always be reversed. The pill gave women control over their fertility. A quick shoulder rub might do the same for men.