Male contraceptive pills

A new study found that a birth control pill was 99 percent effective in preventing pregnancy in mice. But don't expect a human version to hit the shelves ...

But she estimates that it would take 10 years, at least, for the male pill to get on the market. But until these endeavors go through substantial studies — and, critically, trials in humans — a male form of birth control comparable to the pills, patches, shots and rings on the market for women remains a fantasy. In the 1990s, the World Health Organization conducted research into testosterone as a potential form of contraception and found it was highly effective at decreasing sperm counts. Birth control pills for women have also been linked to blood clots. Researchers at the University of Minnesota created a birth control pill for male mice, which proved 99 percent effective in preventing pregnancy. Those match the well-documented side effects women report from hormonal birth control pills. Gunda Georg, a professor of medical chemistry at the University of Minnesota who led the research, pointed out the differences between this study and past attempts to design a male birth control pill: There were no apparent side effects in the mice, even when the researchers tested high doses, she said. Condoms have the additional benefit of protecting people from sexually transmitted infections, but they are “relatively unpopular,” Dr. Najari said. The National Institutes of Health is funding a clinical trial to test a contraceptive gel formulation called NES/T, which men would apply to their shoulders and upper arms once per day. The company bills it as “ the IUD, for men.” Researchers gave this compound, referred to as YCT529, to male mice for four weeks; the animals showed drastically lower sperm counts. But don’t expect a human version to hit the shelves any time soon.

A daily pill shows it can make mice temporarily sterile, and researchers hope to start human trials later this year.

The research received funding from the National Institutes of Health and the Male Contraceptive Initiative, a nonprofit advocating a broader range of birth control options. But condoms are single-use only, and vasectomies aren’t easy to reverse, so researchers have been working on developing a male contraceptive that’s effective, long-lasting and reversible - similar to the birth control pill for women. Scientists in the United States say they have developed a male birth control pill that is 99 per cent effective in mice without causing side effects, and that could begin human trials by the end of this year.