Male equivalents of the female birth control pill are coming closer to reality through research at the University of Minnesota and other institutions, and perhaps just in time, as pressure grows on men to take more responsibility for pregnancy prevention and family planning.

The first male pill seems increasingly within reach due to tests in animals of a molecule called H2-Gamendazole, which U researchers found causes reversible infertility. At the same time, a California foundation is studying an injectable gel that blocks sperm. Nobody’s sure when such contraceptives could reach the market, with funding shortages and research setbacks causing delays.

“The standing joke is that for the last 40 years, we’ve been five years away from having a male birth control pill,” said Rebecca Cuellar, a U researcher testing molecular targets for development as male contraceptives.

Public interest is peaking ahead of scientific breakthroughs, though it’s tempered by worries about possible side effects — and changes in gender roles. A Gustavus Adolphus College survey of 1,872 U.S. adults found that 65 percent of men in long-term relationships and 57 percent of men in short-term relationships would be interested in male contraception in pill or gel form, but it also found some concerns of being perceived as “less of a man.”

People want options for men between the extremes of condoms — which can be used incorrectly — and surgical vasectomies, said Yurie Hong, an associate professor in the gender, woman and sexuality studies program at Gustavus, which commissioned the survey for a Oct. 3-4 conference on reproductive technology.

Respondents were eager to add male contraception as backup while women would continue to use pills or intrauterine devices, she added.

Interest in male contraception comes amid progress in reproductive health. Rates of abortion and teen pregnancy have dropped to historic lows, reflecting a decrease in unplanned pregnancies. Minnesota’s teen birthrate dropped from 36.5 births per 1,000 females ages 15 to 19 in 1990 to 13.7 births in 2015.

Of course, the adoption of long-acting male birth control won’t happen overnight.

The Gustavus survey found 80 percent of women would trust sexual partners in long-term relationships to use male contraception, but only 30 percent would trust men in short-term relationships.

“A partner could say they’ve taken it, and actually not have taken it, and then there isn’t any protection,” said Kirstin Buck, who conducted a similar survey of Gustavus students before graduating this year from the St. Peter, Minn., college with a nursing degree.

Most women in the adult survey said they’d still take birth control pills while their partners used male contraceptives. Most men agreed that they would want women to continue to do so.

Using male contraception as a backup would substantially cut the risk of unplanned pregnancies, though ideally that wouldn’t be because of a lack of trust in sexual partners, said Aaron Hamlin, executive director of the Male Contraception Initiative, which promotes and funds research regarding male contraception.

“If people don’t trust each other, that’s a conversation they’re going to have to have,” he said. “But in terms of the unplanned pregnancy rate, that actually works out just fine.”

A recent study led by the nonprofit initiative predicted a 3 to 5 percent drop in unplanned pregnancies in the U.S. if 10 percent of sexually active men interested in new forms of male contraception actually use them.

The U’s Gunda Georg led the development of H2-Gamendazole, but researchers on campus are looking at other molecules that could serve as contraceptives. Some appear to prevent sperm from swimming or from interacting with female eggs. One target is a molecule that researchers at Bristol-Myers Squibb tested as a cancer agent until they found it had toxic effects on testes.

A male pill is trickier to develop and also must be reliable without causing permanent reproductive damage, Cuellar said. “There’s one female egg that needs to be prevented from getting where it needs to, whereas there are millions of sperm in play.”

A gel called Vasalgel is being studied in animals and promoted by the Parsemus Foundation, a nonprofit organization that advocates for medical solutions that the pharmaceutical industry has overlooked. The gel appears to seal off the vas deferens duct that conveys sperm to the urethra, but Hamlin said it can’t be marketed until a surefire way is found to reverse it.

A trial of an oral male contraceptive is planned in Indonesia, but none is ongoing in the United States. One U.S. trial of a hormonal injection for male contraception was halted last year due to men reporting acne and mood changes, including depression and one suicide attempt.

Cuellar said the U is focused on non-hormonal drug targets that on the surface present fewer risks of side effects.

One dilemma with proposed new methods of male contraception is that, unlike condoms, they don’t protect against sexually transmitted infections. And it comes at a time when the Minnesota Department of Health is already reporting a record increase in detected cases of chlamydia and gonorrhea.

In the Gustavus survey, 70 percent of respondents said they would likely stop using condoms during sex if men used long-acting contraceptives. “Then you’re looking at a possible rise in STIs,” Hong said.

Other concerns emerged. While 76 percent of men said they’d use new male contraceptives if it meant more sex, 29 percent worried that it would make them feel less masculine. That fear was especially true among younger men. In addition, 30 percent of men said they wouldn’t tolerate side effects such as weight gain or mood changes.

Such concerns can be viewed as a double standard; women have long endured side effects from hormonal pills. But Cuellar said the risk-benefit ratio is different; side effects might be worth the risk for women seeking to avoid pregnancy, but not for men.

Buck’s survey of 474 Gustavus students found cost to be the leading factor that would discourage young men from pursuing an injectable contraceptive. She was surprised. Based on the winces she saw when describing the penile injection to male classmates, she figured discomfort with the product would top the list.

In the end, people seem ready for male contraception if the cost can be managed and scientists can overcome the final hurdles, she said.