Rats 'shoot blanks' with U Kansas male contraceptive

A male contraceptive pill tested in rats keeps sperm from developing in the testes while still allowing for a robust libido, researchers at the University of Kansas School of Medicine have discovered.

According to the Nashua Telegraph/McClatchy Newspapers, the compound, created with the chemical compound H2-gamendazole, allows the user to "essentially be shooting blanks" without the use or targeting of hormones.

University of Kansas reproductive biologist Joseph Tash says the pill effect is entirely reversible and doesn't affect male hormones at all. That's based on rat mating tests in which male subjects receiving the pill apparently behaved as amorously as they would have normally. Similarly, Tash's team has tested the compound in rabbits, mice and monkeys, but only for safety (it was safe), not to see if the animals would still mate properly. (Research at Columbia University recently produced a pill that behaves in a similar manner by blocking vitamin A processing, at least in preclinical trials.)

Naturally, researchers must conduct more animal testing to determine whether the pill is both safe and effective before human male subjects are even part of the equation. Tash said he plans to meet with the FDA soon to ascertain what tests are needed, then he'll mull over how to advance to human clinical trials. Optimistically, the Telegraph piece says, the drug is maybe 10 years away from approval, with a high regulatory bar for safety because such a pill would be taken regularly.

But even if a male contraceptive like this comes to market, the article lists plenty of obstacles to its success that go beyond technology and regulatory approvals. One issue is, of course, safety. Male contraceptives using hormones--testosterone and progestin--can theoretically fool the body into not making more sperm. But a global study shut down after severe side effects--including depression--were observed. Tash's compound could cause similar problems.

Furthermore, while researchers continue to tackle how to advance male contraceptive technology into the clinic, the market still may not support such a treatment anyway, even now. A number of pharmaceutical companies pursued male contraceptive research years ago, but pulled out when they didn't see the drug generating much demand. And even if male attitudes are changing (polls show they might be in spades, according to recent FierceBiotech coverage), many men could still be wary of taking a contraceptive pill. It's one thing to say for a man to say he'd be willing to take one, but quite another for him to actually do so.

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