The trial is studying a new male contraceptive, RISUG (Reversible Inhibition of Sperm Under Guidance): a reversible, nonhormonal contraceptive that provides 10 or more years of protection after a 10-15 minute procedure. Researchers received approval this week to begin enrolling additional study volunteers, after a delay of nearly four years.
"RISUG would be exciting because it would mean that, finally, I could take control of my own future, instead of leaving it to someone else," says Dunlap. "Being in a committed long-term relationship means that I don't want to rely on condoms for birth control. I'm not ready for a vasectomy, though. This new procedure could be the answer that gives men the decisive control we lack with current contraceptives."
In the RISUG study, doctors inject a gel into the tube that sperm travel through after they are produced (known as the vas deferens). The gel then disables the sperm as they swim by. In study animals, male fertility returns if the RISUG is flushed out with another injection that dissolves the gel.
Elaine Lissner, director of the nonprofit Male Contraception Information Project in San Francisco, says she is not surprised that American men are watching the RISUG trial with keen interest. She emphasizes that the method has the potential to be the first truly affordable, reversible, long-term male contraceptive.
In 2002, when enrollment in the Indian study was halted, more than 140 men were already using RISUG. Concern about side effects and insufficiency of safety data caused a temporary suspension of the project. However, expert panels subsequently concluded that the major side effect -- several weeks of non-painful scrotal swelling in about a third of the subjects --was not enough to stop the study.
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