Trial results show no major side effects.

In a world first, the pill was tested on British males, and the study found it to be safe to use.

While oral contraception for females has been available for over 60 years, a male version has never been authorised.

The female contraception tablets work by altering hormone levels to reduce the risk of conception.

However, with this method causing common side effects of infertility and mood swings, this approach has proven difficult in men.

One in three men have said they would take the pill if it were available to them.

Now, YourChoice Therapeutics has developed the first non-hormonal contraceptive for men, which works by blocking the production of a protein needed to produce sperm.

The pill does not alter any hormones.

The drug works by stopping the production of retinoic acid receptor alpha (RAR-alpha), which prevents it from binding to vitamin A compounds, subsequently preventing sperm production.

Animal studies proved the pill to be 99% effective in preventing conception.

It also found that sperm returned to normal levels once the medication was stopped.

Human trials began in 2023 on 16 healthy men who had already had a vasectomy.

The trial gave participants either the tablet or a placebo and then measured their blood, urine, mood, and overall health.

Four different dosages were tested, and all were found to be well-tolerated, the highest dose being the same as that shown to be effective as a contraceptive in animal trials.

Data published this week shows the drug to be safe and tolerated with little to no serious side effects.

Scientists found that there was no reduction in testosterone levels, sex drive, or any other hormonal imbalance as a result of the medication.

In their peer-reviewed study in the journal Communications Medicine, the authors wrote: “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."

There will now be further trials to gather more data on the long-term safety of the pill, and if the results are positive, clinical trials will begin.

The study authors noted that the safety bar for contraceptives is much higher and harder to reach than it is for other drugs, as it is preventative and used daily by healthy people for a long period of time.

Akash Bakshi, a co-founder and the chief executive of YourChoice, previously suggested that if the medicine is approved, it should be sent out alongside at-home testing kits for men to check to ensure their sperm levels are too low for conception.

“YCT-529 blocks a protein – not hormones – to prevent sperm production. We believe this will be more attractive to men, most of whom view pregnancy prevention as a shared responsibility even despite today’s limited contraceptive options, which are permanent or only moderately effective.

“The dearth of options reinforces the centuries-old view that pregnancy prevention is ‘a woman’s responsibility’. It’s not, and we’re committed to advancing the first hormone-free birth control pill for men that’s effective, convenient and temporary," he added.