Reader joshtops shares a report: For years, headlines have promised an imminent breakthrough in male contraception. Time and again, these efforts have fallen short. Last October, for instance, researchers reported that a hormone cocktail they'd been testing curbed sperm production and prevented pregnancies. But they'd had to halt the study early because men were reporting troubling side effects, including mood changes and depression. "The joke in the field is that the male contraceptive has been five years away for the last 40 years," says John Amory, a research physician at the University of Washington School of Medicine who has been working on the challenge for two decades. A new form of male birth control would be a public-health triumph and could snag a significant piece of the contraceptive market -- which is expected to surpass $33 billion by 2023, according to research firm Global Market Insights Inc -- or possibly expand it further. In a 2002 German survey of 9,000 men in nine countries, including Brazil, France, Germany, Mexico, and the U.S., more than 55 percent of the respondents said they'd be willing to use a new form of male birth control. A later study by Johns Hopkins University estimated that the demand could yield 44 million customers in those nine countries alone. And yet major pharmaceutical companies have mostly abandoned the chase.