For decades, the responsibility of taking a birth control pill has been placed firmly on the shoulders of women.
But that could soon change – as an experimental pill for men that works by blocking sperm production has just passed its first safety test in humans.
The hormone–free contraceptive tablet, called YCT–529, has already been found to prevent 99 per cent of pregnancies during experiments in mice.
It works by blocking access to vitamin A in the testes, preventing sperm production without affecting testosterone levels – meaning libido is not impacted.
The male pill, which experts hope will be available this decade, is the only one currently being tested in humans.
For the latest trial, researchers recruited 16 men who were put on different doses of the pill across several days.
Instead of testing how effective it was in humans – all of the men had undergone vasectomies – the aim was to discover if there were any side–effects.
Analysis revealed there were no concerning changes in heart rate, hormone function, inflammation, mood or sexual function.
The results of this early trial are a critical next step towards getting the male contraceptive pill approved (file image)
Next, the team will test the pill in larger trials that will look at how effective it is in preventing sperm production in humans.
The results of the safety trial, published in the journal Communications Medicine, are a critical first step toward getting the pill approved, experts said.
‘We really need more reversible contraceptive methods for men,’ Dr Stephanie Page, an endocrinologist at the University of Washington School of Medicine and who wasn’t involved in the study, told Scientific American.
Currently, the other male birth control options are vasectomies – a surgical procedure that involves cutting and sealing the tubes that carry sperm from the testicles – or condoms.
Vasectomies, also known as ‘the snip’, can be reversed but the success rate of reversal procedures vary widely.
Earlier tests in male primates also found the drug lowered sperm counts within just two weeks.
Crucially, both mice and non–human primates fully regained fertility after stopping the drug and no side effects were detected in either species.
Mice regained fertility within six weeks, while non–human primates fully recovered their sperm count in 10 to 15 weeks.
The non–hormonal drug called YCT529 works by inhibiting a protein important for the normal development of sperm. Pictured, existing oral contraceptive pills (file photo)
YCT–529 is being worked on as part of a collaboration between University of Minnesota College of Pharmacy, Columbia University in New York and San Francisco–based firm YourChoice Therapeutics.
‘A safe and effective male pill will provide more options to couples for birth control,’ Gunda Georg, chemist and pharmacist at the University of Minnesota, said earlier this year.
‘It will allow a more equitable sharing of responsibility for family planning and provide reproductive autonomy for men.’
Both the animal studies and the human trial results suggest that the approved pill would likely be taken once a day, but further trials will confirm that dosing.
‘The positive results from this first clinical trial laid the groundwork for a second trial, where men receive YCT–529 for 28 days and 90 days, to study safety and changes in sperm parameters,’ the study authors wrote in their paper, published in the journal Communications Medicine.
Currently, around a quarter of women who use contraception take an oral birth control pill, but there are no equivalent methods available for men.
If the male pill proves to be as effective in humans as it is in mice, it would be on a par with the female birth control medication.
Lead author and YourChoice Therapeutics’ Chief Science Officer Nadja Mannowetz said: ‘A peer–reviewed publication for our first–in–human study reinforces YCT–529’s strong safety profile.
Graphs from a previous study in cynomolgus monkeys demonstrate a decrease in sperm count while taking the pill, and recovery of sperm counts after stopping the drug
‘It also shows “the Pill for men” had no effect on sexual desire or mood.’
Nearly half of all pregnancies globally are unintended, suggesting an urgent need for more male contraceptive options.
There is also high demand for new methods.
A recent study showed men are very interested in using new male contraceptive options and women are confident they’ll take them correctly.
‘Studies and surveys continue to show that men want to share the burden of pregnancy prevention with their partners,’ Akash Bakshi, CEO of YourChoice Therapeutics, said.
‘But they have just one non–permanent contraceptive option—condoms—and it’s 170 years old. Innovation is long overdue.
‘Data show men favour an oral contraceptive and one that’s hormone–free, positioning YCT–529 as potentially transformative for a healthcare segment that’s been stagnant for more than a century and a half.’
Women have several birth control options available including short–term rapid methods like birth control pills and patches and a contraceptive cap or diaphragm.
They also have long–term options such as implants, which produce hormones that stop the release of an egg.
Some opt for an intrauterine device – a T–shaped device placed into the uterus to prevent an egg from implanting.
The birth control pill or patches are about 93 per cent effective at preventing pregnancies.
However long–term devices like the intrauterine device are more than 99 per cent effective.
