A lack of demand has held up the arrival of the male contraceptive. Until now

Emeritus Professor John Guillebaud [UCL Obstetrics & Gynaecology] 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. …

Genevieve Roberts 'The Independent'