A lack of demand has held up the arrival of the male contraceptive. Until now,says Genevieve Roberts

Recent reports that a male pill will revolutionise contraception choices imminently may have sounded familiar. For the last decade, a reversible male contraceptive has been five years from coming on to the market. The first trials began in 1990. So why are we still waiting?

One of the reasons the male pill has taken so long to arrive is because of suspicions that there is no market for it. But pharmaceutical company Schering and Organon seems convinced that men could be persuaded to use a chemical contraceptive, and the five-year prediction may at last have a ring of truth.

John Guillebaud, professor emeritus of family planning and reproductive health at University College London, says: "It is rather like the tide coming in, an incremental process, and it comes in a little further each time. But I do believe that the male pill will happen." He believes implants would be the most effective delivery method. "Men cannot be relied upon to take tablets," he says. "The contraceptive injections and implants have a far higher success rate for women. For men, this will be even more important because they do not have the investment in avoiding a baby."

Professor Guillebaud expects that by 2011 there will be implants with supplementary injections, and by 2016, an implant that can be buried under the skin for three years. "This will be ideal," he says, "Because men are wimps when it comes to pain." The male contraceptive consists of two hormones, progestin and testosterone. Progestin stops the pituitary glad making the hormones that stimulate sperm production, while testosterone, in the form of androgen, stops fatigue, hair loss and replaces the libido. The amount of androgen must be carefully balanced, to avoid mood swings or increased violence.

Earlier this summer, Dr Peter Liu at the Los Angeles Biomedical Research Institute published an analysis of 1,500 individuals who have taken part in male contraceptive trials over the last 15 years. He found that men regained full fertility (20 million sperm per ml) after three to four months of not taking the hormones. "These findings pave the way for new drugs that allow men to share the burden of family planning more fairly," he says.

The main fear about the male pill is that, like the female Pill, its long-term effects cannot be known until people try it. David Neal, professor of surgical oncology at Cambridge University, says minor hormonal changes can alter the risk of prostate cancer - although they could have a positive effect. He expects that male contraceptives will be most popular with couples in long-term relationships because, like the female Pill, it will offer no protection against sexually transmitted diseases.

Richard Anderson, professor of clinical reproductive science at Edinburgh University, who has led a series of trials, believes both the male pill and implant should be made available. "The implant is likely to be the first method available, but in surveys men in Britain have said they would rather take the pill." His latest studies have been "very positive", using two implants which dissolve over several months.

Development has been hindered by a lack of investment, but he says it is "very encouraging" that pharmaceutical companies are now backing major studies. "The industry has been reluctant to believe that there really is a market for this."

There has also been a lack of development of new forms of testosterone, so until recently men have needed a injection every few weeks. And when will we see a drug for the public? "A few years - it still needs a big Phase III study, but people can now see how it is going to pan out," says Anderson.

Schering and Organon conducted the biggest EU study into implants with injections between 2004 and 2005. It will announce in the autumn whether it will back a Phase III study, the final stage before an implant comes on to the market.

Astrid Kranz, a spokeswoman for Schering, says the investment in male fertility control is dictated by society's demands. "The role of men has changed. Bringing up children is now shared more equally between men and women. If men had said from the beginning they really want this, it would have given it more of a dynamic."

'I suffered mood swings and night sweats'

Clint Witchalls, 40, from Brixton, took part in a male contraceptive trial in May 2004. He had a plastic rod implant in his left arm, which lasted a year. He was monitored for six months after it was removed, and has been told his sperm production has returned to normal.

"A lot of men are interested in taking responsibility for contraception, and this is a good option for men in long-term, monogamous relationships," he says. But he did suffer from side-effects. "I had huge mood swings that started a few weeks after having the implant, which became more severe and tipped into depression. That may have had nothing to do with the drug, though. I also had night sweats."

Despite his experience, he thinks the male implant is a good idea. "Some women have adverse reactions to the female Pill, but that is not a reason to pull it off the market. I have not been told by the drugs company whether I was on the placebo or the contraceptive, but I think it was the latter."

Clint Witchalls is currently writing The Pill and I, to be published by Rowohlt next year.