Three U.S. sites are enrolling couples in the first clinical trial to test the safety and efficacy of a gel for men to prevent unintended pregnancy. (Trial subjects' criteria and investigators' contact info at clinicaltrials.gov)

Today’s launch was announced jointly by the Population Council, the National Institute of Child Health and Human Development (NICHD), the Los Angeles Biomedical Research Institute and the University of Washington School of Medicine.

The gel being tested is composed of Nestorone® (segesterone acetate), a progestin hormone used for female contraception, and testosterone. NES/T is a novel, reversible contraceptive for men designed to be absorbed through the skin on the upper arms and shoulders.



Drs. William Bremner and Stephanie Page will lead the study site at the UW School of Medicine.



“The potential of this new gel is huge,” said William Bremner, professor of medicine at the UW School of Medicine and trial director in Seattle. “There is a misperception that men are not interested in, or are even afraid of, tools to control their own fertility. We know that’s not the case.”

[Download video soundbites of Drs. Bremner and Page discussing the trial.]

Previous multinational surveys have shown that more than half of men say they would use a male contraceptive if it is reversible and uncomplicated. Proving efficacy and acceptability is essential to overcoming misperceptions that men aren’t interested in new contraceptive options.

“We hope that results from this trial will help pave the way for renewed interest in male contraceptive development and propel this important public health work forward,” said Stephanie Page, a UW professor of medicine and a study principal investigator.

The NES/T gel trial is sponsored by the NICHD, part of the National Institutes of Health, and co-directed by the Population Council and NICHD. Couples are being recruited throughout the NICHD’s Contraceptive Clinical Trials Network (CCTN). The trial is first launching in Seattle, Los Angeles, and Kansas City (Kansas) and later will include sites in Chile, England, Italy, Kenya, Scotland, and Sweden.

Worldwide, 85 million pregnancies (40 percent of all pregnancies) per year are unplanned, contributing to a higher incidence of adverse health outcomes for women and infants. Apart from condom use, withdrawal during sex, and vasectomy, no other contraceptive options exist for men.

“Expanding male contraceptive options could help make family planning more of a shared responsibility between women and men,” said Regine Sitruk-Ware, distinguished scientist at the Population Council’s nonprofit Center for Biomedical Research and co-director of the trial. “Safe, effective, and reversible tools for men to control their own fertility gives new meaning and significance to the term ‘family planning.’ No matter the challenge, we must continue to innovate and develop new products to improve lives.”



The NES/T gel is designed to decrease a man’s sperm production without reducing his sexual drive or enjoyment. Photo by Hallie Easley/Population Council



More than 400 couples are anticipated to enroll in the Phase IIb trial, which is the first to test the gel product for contraceptive efficacy, or pregnancy prevention, in the female partner.

“We have been developing this product for more than a decade,” said Diana Blithe, chief of NICHD’s Contraceptive Development Program and director of the CCTN. “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.”

Men and their female partners are active participants in the study. Men will apply the gel once every day. Once the man’s sperm count reaches an appropriate level to prevent pregnancy—a process anticipated to take eight to 16 weeks—the couple will be informed that they should begin to use the gel as their only form of contraception for one year. During this phase, the man’s sperm count will be checked regularly to help minimize the possibility of pregnancy.

The NES/T gel is designed to decrease a man’s sperm production without reducing his sexual drive or enjoyment. The trial will also test the acceptability of the daily gel application as a contraceptive among the participating couples—a critical measure for real-world use.

“The success of a reversible contraceptive for men requires an approach that reduces the production of sperm without impacting a man’s testosterone levels or ability to produce sperm at a later date,” said Christina Wang, Los Angeles Biomedical Research Institute lead researcher and a study principal investigator. “The challenge is achieving the right combination of Nestorone and testosterone at the right time.”

Results from the trial are expected in 2022 and will help determine whether the NES/T gel should be evaluated in a separate, larger-scale Phase III contraceptive efficacy clinical trial, with the aim of obtaining approval from the U.S. Food and Drug Administration to market the product as a male contraceptive.

[Interested couples can find site investigators' contacts information and selection criteria here.]