Contraceptive pill for men that 'blocks sperm' in final development stage

A male contraceptive pill that "blocks sperm" and increases libido is about to enter what could be the final stage of development in a major medical breakthrough.

The first hormone-free and reversible male pill that wouldn't impact libido or fertility pill is being developed by Australian researchers at Monash Institute of Pharmaceutical Sciences.

The Male Contraceptive Initiative has provided a $US150,000 ($206,000) grant for the Melbourne scientists to move into the next phase of developing the drug which would work by blocking two proteins that cause sperm to be released, according to lead researcher Dr Sab Ventura.

"It just stops the contraction of the muscle which would normally be moving sperm along. So the sperm are fine, they haven't been touched, they're still completely normal, they just haven't been moving at the right time," he said.

If the final stage of development is successful, trials would then commence and the pill could be on the market within five to 10 years.

Dr Ventura said the team was "moving closer to developing a convenient, safe and effective, non-hormonal oral male contraceptive that can be readily reversed".

"We aim to do this by developing a combination of two drugs that simultaneously block sperm transport rather than disrupt sperm development or maturation," Dr Ventura said.

"It's pretty different. Most of the other ones that have been tried have been affecting hormones or genetics."

Dr Ventura this morning told Melbourne's 3AW there was a desperate need for a male contraceptive pill on the market so "both parties could make the choice who would rather be taking the contraception".

"There might be a very effective one for women already but there's still about 80 million unwanted pregnancies a year so there's obviously not enough options to keep everybody happy," he said.

"So we need as many (options) as we can get."

Social media users have previously expressed their support and criticism of the concept of male birth control.

"Any extra protection against pregnancy is a good thing. Like the idea of relying in myself as opposed to just my partner," one Twitter user wrote.

"I'd never leave this responsibility in the hands of anyone but myself," another posted.

The pill would bypass the side-effects that have up until now hindered development of a male contraceptive pill, according to the researchers.

Such side-effects include long-term irreversible effects on fertility, birth defects in future offspring and libido and are often caused from interfering with male hormones.

Previous research in mice showed male infertility was achieved when two proteins that trigger the transport of sperm — a1A-adrenoceptor and P2X1-purinoceptor — were deleted.

The drug could also have a second function on users by increasing libido in men.

"The mice had normal sexual behaviour and the type of drugs we're looking at may improve sexual function in men because they dilate blood vessels and that is what Viagra does," Dr Ventura said.

But its development and release date is all dependent on funding, according to researchers.

"The question's not 'how long?' it's more about 'how much?'" Dr Ventura said.

"The faster the money comes in, the faster it will happen."