A new reversible male contraceptive
A reversible, nonhormonal male contraceptive has been tested by volunteers in India for the last 15 years, but the tests were stopped 4 years ago because of concerns about side effects. Now, this contraceptive has again received approval to begin enrolling additional study volunteers. This new male contraceptive, which uses a gel to disable active sperm, is called RISUG (short for Reversible Inhibition of Sperm Under Guidance), "provides 10 or more years of protection after a 10-15 minute procedure." But tests in the U.S. should not start before several years.
Here is how this male contraceptive works according to the Male Contraception Information Project.
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.
If this method is effective and affordable, why the testing process was stopped?
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.
So now that new volunteers can test this contraceptive, what will come next?
Currently, RISUG's developers are arranging a collaboration with US researchers. Elaine Lissner, [director of the nonprofit Male Contraception Information Project in San Francisco,] says that to gain FDA approval, US researchers will have to begin with animal tests, so studies in North American men would not start for several years. Still, she notes that "We shouldn't be discouraged. We already know that RISUG works, which is half the battle in drug development. Men in studies in India have been using it for more than a decade. Now we just have to finish our homework."
For more details about this new male contraceptive, here is a list of some recommended resources.
- "Frontiers in Nonhormonal Male Contraception: The Next Step," a very well-documented paper from the Male Contraception Information Project
- A page about RISUG from the Global Male Contraceptive Coalition
- And another one from Wikipedia
- The U.S. patent #5,488,075 "Contraceptive for use by a male"
And to reinforce what was said above, Wikipedia does a good summary of the advantages of RISUG. This new method is fast, convenient, non-surgical, long-lasting, has few side effects, and above all, is reversible.
But even with all these advantages, it will be a long time before this contraceptive becomes available.
Sources: Male Contraception Information Project news release, March 30, 2006; and various web sites
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