Rumours of the imminent invention of a birth control pill for men have been doing the rounds for at least a couple of decades, but in 2011 men who want to take control of their contraception are still limited to condoms, vasectomy or being very careful with their timing.
So what's happened to the 'male pill'? Is a reliable contraceptive for men in faithful long-term relationships just around the corner, or will men have to rely on the old methods - unsatisfactory or plain risky as they are - for the foreseeable future? MSN Him reveals everything you need to know about the male pill.
Do men want the male pill?
Do men want the male pill and are we likely to forget to take it?
Part of the reason men are still waiting on the male pill is that nobody is sure if we - or the women in our lives - really want it. In April 2011, for example, a survey revealed that most women wouldn't trust their partners to take the male pill.
According to Susan Walker, senior lecturer in sexual health at Anglia Ruskin University, "while the female interviewees loved and trusted their male partners, some of them simply felt that men are, as a gender, more forgetful."
We'd forget to take the pill because we don't have the threat of pregnancy hanging over us, the research suggested, and also because we just don't like the idea of mucking around with our hormones.
Many of the men questioned for the study worried that a male pill would undermine their masculinity.
Such attitudes - and they are common - have lead some pharmaceutical companies to conclude that the male pill is not the potential goldmine they once thought. But there are teams of researchers still working on the male pill, so how far have they got?
History of the male pill
For many years, the answer seemed to be that we were within a whisker of the male pill - or at least the male contraceptive injection. In 2003, for example, Australian researchers claimed a major breakthrough with a three-monthly injection of the hormone progestogen, which showed huge promise in blocking sperm production.
Other researchers had tested progestogen too, but the side effects - a reduction in libido and bone thinning, among others - were considered too harsh. But by combining progestogen with a four-monthly injection of testosterone, the researchers seemed to have found a combination that worked.
Research into the male pill has struggled to deliver a breakthrough
And now, eight years later, the trail has gone cold. There is no sign that the Australian research will turn into a working product any time soon.
And that has been - for the most part - the recent history of the male pill. Researchers make bold claims, newspapers report that a working pill is imminent, and then everything goes quiet.
Why is the male pill delayed?
The problem is that producing a male pill is actually a very tough ask. An effective contraceptive for women has to block one egg a month. An effective male pill would have to block the production of 1,000 sperm a second, or render every single one faulty. It only takes one sperm to fertilise an egg, so there's no room for error.
The one reasonably certain way of doing that at the moment is vasectomy. But vasectomy is only an option for men who don't want any - or any more - children. A successful contraceptive pill for men would have to have the power to foil the designs of millions of sperm, but produce no permanent damage to fertility.
And as the progestogen research shows, there's also the problem of side effects. Hormonal contraceptives could lead to problems with libido and erections, which would add to their effectiveness in stopping pregnancy but not in a way any man would accept.
"Men don't cope well with side effects and having side effects would probably put many off wanting to take a pill," according to Professor Haim Breitbart of Israel's Bar-Ilan University, an expert in contraception.
The holy grail
The holy grail of research is a working male pill, taken infrequently, orally
Despite those difficulties, there are a number of researchers who seem to be edging towards a solution.
At the moment it looks like a contraceptive injection or implant for men could be the first to make it past the testing stage and onto the market. Researchers at the University of Washington have been testing a sustained-release, testosterone-based contraceptive, administered by injection under the skin.
The problem with injections is that - well - they're injections. Both injections and implants would have to be administered by a doctor, and men are notoriously poor at visiting the doctor at the best of times.
The holy grail, then, is still an oral pill, and the most promising research may be Professor Breitbart's in Israel. His pill doesn't block sperm production - notoriously difficult to get 100% right - but instead removes a vital protein from sperm effectively rendering them infertile.
Tests on mice have so far proved 100% effective, and according to Professor Breitbart, "we couldn't see any behavioural side effects - all their sex behaviour was retained, which is a very important consideration for men."
And this pill nicely gets past one of the chief female concerns. Men would only have to remember to take it every one or three months, not every 24 hours. "I think most women would trust their man to remember once a month or once a quarter," adds Professor Breitbart.
Male pill still five years away
The male pill is still five years away
Professor Breitbart's pill is due to start human testing this year, and is likely to be available in around five years' time.
As for injections and implants, Dr Andrea Coviello - who is working on the University of Washington research - says it's just a matter of funding. Many researchers believe a hormonal contraceptive of some sort for men could be available within two or three years.
Until then, we'll just have to stick with condoms or rely on our partners for birth control. And whether we'll all rush to take a male pill or not even when it becomes available, is another question altogether.
- Body image issues: how to resolve the most common
- How to speed up your metabolism
- How to flatten your stomach for life
Share this story with friends and family, join MSN Him on Facebook
Be the first to see the latest news, features and what we're up to, follow MSN Him on Twitter