For men seeking a contraceptive, the choices are starkly limited: a vasectomy, which requires surgery and is not readily reversible, or condoms, which many men find uncomfortable. The responsibility therefore often falls to women, who have more options. Research on male contraception is growing, however, and the Bill and Melinda Gates Foundation is sponsoring an international conference on the subject later this year. Here, a brief guide:

Why the new interest in male contraceptives?
Many contraceptives for women carry health risks, including cancer, high cholesterol, weight gain, and high blood pressure. These concerns, as well as men's interest in having more options, are helping to spur more research into male contraceptives. "We have a number of irons in the fire," says Diana L. Blithe of the National Institute of Child Health and Human Development, as quoted in The New York Times. "I think men actually do want to do this."

Is there a pill for men yet?
They're working on it. Experts at the University of Kansas Medical Center are experimenting with a pill called gamendazole that interrupts sperm development so men are essentially making "nonfunctional sperm." Another drug, originally used to prevent infections, also inhibits the production of retinoic acid, which is essential for sperm production. Researchers also are looking at other methods, such as heating the testicles using ultrasound, which can stop sperm production for months.

Are these methods safe for men?
It will take further research to determine how safe these contraceptives are; some will probably not make the cut. The drug that blocks retinoic acid, for example, also causes sickness when combined with alcohol, so that contraceptive might get shelved. As one scientist says, "The joke is, if it weren't for alcohol, no one would need contraception."

But will men actually use birth control?
Though some men will always resist using birth control over health concerns or fears of putting "poisons" in their bodies, more men are expressing interest in using contraceptives that are safe, effective, and reversible. "I would definitely do some kind of long-term male contraceptive," says Steve Owens, a volunteer in a clinical trial of male contraceptives, as quoted in The New York Times. Though his sperm count dropped during one trial period, which rendered him "not viably able to produce a child," his sperm count soon rebounded. He and his wife now have a young daughter.

Sources:,, NY Times, UPI