Male contraceptive pill 'a step closer', scientists say

Small changes to a previous version of the male pill make it effective over a longer period and easier to take

A report suggests that scientists may have have taken a step closer to making a safe contraceptive pill for men (iStock)

Scientists believe they have taken a step closer to making a safe contraceptive pill for men, according to a report.

Fifty years after the female pill, researchers have yet to find a way to render men temporarily infertile without significant side-effects.

However, academics at Minnesota University told the American Chemical Society’s annual meeting on Sunday that they had made a significant advance, The Times reported.

The scientists reported that they had made small changes to a previous version of the male pill to make it effective over a longer period and easier to take.

Gunda Georg, head of the research team, spelled out what a male pill would have to be like before it could go on sale.

“It would have to be soluble so it could be taken by mouth. It would start working fairly quickly and it wouldn’t diminish libido. It would be safe even if taken for decades,” she said.

“And because some users would eventually want to have children, its impact on fertility would be reversible, with no lingering ill effects on sperm or embryos.”

Their work built on findings of a study published last year that identified an enzyme used by sperm to get inside the egg.

John Herr, a professor of cell biology who worked on that study, said: “Understanding at the molecular level exactly how the sperm is able to bind with and enter the egg, opens opportunities to identify molecules that can disrupt or block the fertilisation event.”

The male hormone testosterone has been used before as it can produce temporary infertility, without affecting libido.

Jillian Kyzer, one of the research team, said: “At certain doses, testosterone causes infertility, but at those doses it doesn’t work for up to 20 per cent of men, and it can cause side-effects, including weight gain and a decrease in ‘good’ cholesterol.”