Researchers are testing a male contraceptive gel that’s shown early signs of working—but it still faces hurdles

A federal effort is under way to develop a new kind of male contraceptive, a development that scientists say would be an important public-health breakthrough. It’s also an effort that has struggled for years.

The National Institutes of Health plan to start recruiting couples soon for a clinical trial of a gel that is applied to men’s shoulders.

The gel includes the hormone progestin, which prevents the testes from making testosterone at a level that supports sperm production. It also contains testosterone to maintain normal blood levels to try to prevent a hormone imbalance that might cause side effects.

An easily accessible contraception for men could have far-reaching effects, though scientists don’t expect a male contraceptive to have as huge of an impact as the introduction of birth control pill decades ago. They expect it to reduce unintended pregnancies. It would allow men to better control their own fertility. It could also allow women to discontinue their birth control.

Efforts at developing a male contraceptive have been held back by lack of interest from big pharmaceutical companies. A large human clinical trial several years ago ended early because some participants experienced depression and mood disorders.

The NIH trial is expected to take about three years. If successful, researchers would move on to another trial. That means any commercial product is years, or even a decade, away.