MONDAY, June 3, 2024 (HealthDay News) -- A new hormonal gel could one day be a potential form of birth control for men, researchers reported Sunday.

“The development of a safe, highly effective and reliably reversible contraceptive method for men is an unmet need,” senior study author Diana Blithe, chief of the Contraceptive Development Program at the National Institutes of Health, said in a news release announcing findings that were presented Sunday at the Endocrine Society's annual meeting in Boston.

In the phase 2 trial, 222 men applied 5 milliliters of the gel (the equivalent of a teaspoon) to each shoulder blade once a day.

The result: 86% of the men reached sperm suppression. On average, the timing for effective contraception was eight weeks, which was faster than expected.

“While studies have shown that some hormonal agents may be effective for male contraception, the slow onset of spermatogenic suppression [has been] a limitation,” Blithe noted.

But because this gel includes both testosterone and Nestorone, a synthetic hormone already used in the vaginal contraceptive ring, it acts more quickly and requires less testosterone, she explained.

Blithe added that earlier studies of male hormonal contraceptives given by injections showed a median time of between 9 and 15 weeks for sperm output to become suppressed.

“A more rapid time to suppression may increase the attractiveness and acceptability of this drug to potential users,” Blithe said.

Researchers are now tracking how well the gel works. Male volunteers must be in committed, monogamous relationships and they need consent from their female partners. The couple must agree to use the gel as their only birth control and to have sex at least once a month for a year, NBC News reported. Throughout the study, men will have their sperm counts tested periodically.

“We’ve been pushing for hormonal male contraceptives for 50 years, but there isn’t enough money available to really drive something through a very large phase 3 trial,” Daniel Johnston, chief of the National Institute of Child Health and Human Development’s Contraception Research Branch, told NBC News.

However, if one male birth control drug was approved by the U.S. Food and Drug Administration, pharmaceutical companies may put more resources into similar medications, Johnston added.

“We’ve been chasing this for a long time,” Johnston noted. “I hope we’re entering new territory.”

Also at the Boston meeting, YourChoice Therapeutics reported that a very small British trial -- just 16 men -- showed that its non-hormonal pill, YCT-529, was safe and free of side effects. The San Francisco company’s pill works by blocking the vitamin A receptor important for male fertility, NBC News reported.

YourChoice is planning a larger trial, according to CEO Akash Bakshi.

“We’re excited to see what happens next,” Bakshi told NBC News.

The big question is whether men will use birth control drugs.

Surveys have found that men are willing to use contraception, gynecologist Dr. Brian Nguyen, one of the investigators on the gel clinical trials, told NBC News.

“By and large, they always say they’d be interested,” said Nguyen, an associate professor of obstetrics and gynecology at the University of Southern California.

According to a 2023 survey published in the journal Contraception, three-quarters of just over 2,000 male respondents said they would try new contraceptives.

Heather Vahdat, executive director of the Male Contraceptive Initiative, said interest in male birth control has been on the rise since the Supreme Court overturned Roe v. Wade in June 2022.

Recent research from the University of Pittsburgh School of Public Health found that the number of young women and men choosing permanent birth control such as vasectomy and tubal ligation has increased sharply after the court’s decision.

A separate report, conducted in part by the Male Contraceptive Initiative, showed that before the abortion ruling, 78% of American men were interested in trying new birth control methods. Afterward, it climbed to 82%.

“The demand has always been there, but there’s a greater intensity now,” Vahdat said. “We get emails daily from people asking where they can sign up for clinical trials.”

Unlike a vasectomy, the new contraceptive approaches are meant to be reversible, so men can regain their ability to have children if desired.

While condoms can be highly effective against pregnancy or sexually transmitted infections when used perfectly, that is hard to achieve. And they aren’t the preferred contraceptive in long-term relationships, Bakshi noted. 

More information

The American Association of Medical Colleges has more on male birth control.

SOURCE: Endocrine Society, news release, June 2, 2024; NBC News