the new birth control pill for men

 

Male contraceptive pill prototype stops sperm swimming

 

According to scientists who discovered a cell pathway, or switch, that prevents sperm from swimming, an on-demand, the non-hormonal male contraceptive pill could be a real possibility.

According to mouse tests, it stuns sperm for at least a few hours, long enough to prevent them from reaching the egg.

Many more tests are planned and required, with rabbits taking precedence over humans.

 Users could take a pill an hour before sex and watch the clock to see when it wears off.

How does it function?

It does not contain any hormones, unlike the female contraceptive pill.

 One of the advantages of the approach being investigated, according to scientists, is that it will not knock out testosterone and cause any male hormone deficiency side effects.

 The "sperm-swim" switch they're after is a cellular signaling protein called soluble adenylyl cyclase, or sAC. The male pill under investigation inhibits or blocks sAC.

A single dose of the drug, called TDI-11861, immobilized sperm before, during, and after mating in an early study in mice funded by the US National Institutes of Health and published in the journal Nature Communications.

 The effect lasted approximately three hours. It appeared to have worn off completely after 24 hours, with the next batch of sperm swimming normally.

 Dr. Melanie Balbach of Weill Cornell Medicine in New York, one of the researchers, said it showed promise as a reversible, easy-to-use contraceptive.

 If it does eventually work in humans, men may be able to take it only when and as often as they need to. They could make day-to-day decisions about their fertility.

 "There is a pressing need for an effective, reversible, oral contraceptive for men," said Prof Allan Pacey, professor of andrology at the University of Sheffield.

 "The approach described here, to knock out key enzyme in sperm that is critical for sperm movement, is a  novel idea. The fact that it can act and be reversed so quickly is very exciting.

 "If the trials on mice can be replicated in humans with the same degree of efficacy, then this could well be the male contraceptive approach we have been looking for. 

However, experts warn that it will not protect against sexually transmitted infections. Condoms would be required.

"There is a pressing need for an effective, reversible, oral contraceptive for men," said Prof Allan Pacey, professor of andrology at the University of Sheffield.

 "They had already done a few tests on sperm cells in the laboratory and it works in the same way. So that, I believe, genuinely opens up the possibility of some human trials."

 Other researchers, meanwhile, have been investigating a slightly different pathway to stop sperm swimming by blocking a protein on the surface of sperm.