A male contraceptive pill will eventually be produced, but it will have to overcome “the attitude of men”, the American biologist Gregory Pincus said. Pincus, the “father of the pill” for women, made that prediction when visiting Sydney – in 1964.

The pill had arrived in Australia just three years earlier, bringing the sexual revolution with it. Since then, the hormonal level and mix has been improved and long-acting contraceptives such as implants and intrauterine devices have added to women’s options.

But 60 years after Pincus’s pronouncement, vasectomies and condoms remain the only contraceptive options for men – leaving women with the financial burden, the mental load and the side effects of preventing unwanted pregnancies.

Over that time, promising products have popped up, but, despite regular headlines claiming a pill is just around the corner, none has made it to market.

Some have blamed double standards and sexism in medicine. Trials have been cancelled because of side effects that are similar to those women put up with, including mood changes, acne and reduced libido.

By 1964, Pincus had been experimenting with sperm-stopping pills for six years.

“One of the biggest problems standing in the way of scientists is the attitude of men generally,” he said. “Many feared a contraceptive pill would interfere with their sex drive. [That] can’t be considered acceptable.”

‘It’s like the IUD, for men’

While gendered hurdles remain, some think attitudes are finally shifting. And there are (again) promising hormonal and non-hormonal products on the horizon.

Louise Keogh, a health sociology professor at the Melbourne School of Population and Global Health, says she is cynical but still hopeful that one day men will have access to reversible contraception.

“Every five years there’s a new drug, it works, it stops the production of sperm or there’s another mechanism,” she says.

“The pattern seems to be they get to trial, then there are reported side effects and a ‘delayed return of fertility’, then they give up on it.

“The side effects are often very similar to what’s reported for women. Mood swings, weight gain, acne … I don’t understand why a delayed return of fertility would be a dealbreaker.

“So I’m very cynical when I hear of a new trial because I’ve heard it so many times before.”

In 2016, the trial of an injection that lowered sperm counts to prevent 96% of pregnancies was aborted because of too many side effects. Some men suffered acne, weight gain or mood swings.

There were more serious problems – one man developed severe depression and another became suicidal (the female contraceptive pill can also cause depression) – but other trials have been stopped because men found the side effects of safe and effective treatments “unacceptable”.

That could be one reason the pharmaceutical industry has historically shown a “lack of interest” Keogh says, even though studies have shown enough men would be interested to make a contraceptive commercially viable.

Contenders include ways to suppress sperm production, motility (the ability for sperm to move efficiently) or ability to fertilise an egg, and ways to stop the sperm from leaving the vas deferens.

Researchers have tested testosterone and progestin, a “switch” that stuns sperm, and a polymer that blocks tubes.

Dundee University researchers have been working on a range of options, with help from Bill and Melinda Gates Foundation grants. They have tested thousands of already approved drugs and say they have found effective ways to “halt the sperm in its tracks”.

The biotech company Contraline is trialling an injectable non-hormonal hydrogel that blocks the path of sperm. “It’s like the IUD, for men,” the company says.

The US National Institute of Child Health and Human Development is conducting clinical trials, including of a hormonal gel that men rub into their shoulders to reduce sperm production. The National Institutes of Health have tested a compound on mice that stops sperm being able to move.

Societal changes

The medical director of Family Planning Australia (FPA), Dr Clare Boerma, says there have been “big shifts” in attitudes among men and in society generally. Traditionally contraception was seen as women’s responsibility, particularly within relationships, so women bore the side effects and the cost.

But the number of vasectomies is on the rise. FPA’s service is booming and it now has a waiting list, Boerma says.

Medicare statistics compiled by Vasectomy Australia show a 75% increase over the decade to 2022-23 from 22,213 in 2013-14 to 38,875.

“We do hear from both men and women there’s a desire for more options for men … some men find the idea of a vasectomy terrifying,” Boerma says.

“Societal attitudes are shifting and there’s probably more demand for it now. The more options the better.”

Last year a Senate inquiry into universal access to reproductive healthcare found male contraceptives were “an effective method to prevent pregnancy”. It noted that women disproportionately bore responsibility for contraception.

“This results in women commonly carrying greater financial costs as well as incurring any associated health burdens that may result, such as common negative physical side effects and the consequences of contraceptive failure,” it found.

The government is currently considering the report.

“All too often the burden of, and responsibility for contraception falls solely on women,” the assistant health and aged care minister, Ged Kearney, says. “It’s important that both men and women have a range of contraceptive options available to them.”

Boerma says when and if a male pill is finally available, it will spark a range of new questions and conversations around responsibility, trust and consent.

“And the motivations for someone to put up with side effects … the question has been whether the motivators would be different and whether women would trust partners [to keep taking the contraceptive],” she says.

“It’s a new space – developing a drug to prevent a condition in another person.”