Female Viagra and FDA not a happy match

The U.S. Food and Drug Administration is asking a panel of experts to weigh in on a women's version of the male sexual dysfunction drug Viagra.

The FDA is considering Boehringer Ingelheim's drug flibanserin as a treatment for premenopausal women who report a lack of sexual desire. This is the latest drug in the quest for a female Viagra which drugmakers have been after since the huge success of Viagra. On Friday a panel of experts will discuss the safety and effectiveness of the drug. The FDA isn't required to follow the panel's advice.

The FDA's own review says two Boehringer studies failed to show a significant increase in sexual desire as recorded by women testing the drug. Flibanserin was first studied in both men and women as a treatment for major depression. Those drug trials showed the drug wasn't effective for that purpose but did show an impact on sexual function, which prompted the drugmaker to pursue it as a treatment for female sexual dysfunction, the FDA says.

The drug affects serotonin and several other brain chemicals and it's not clear how that increases sex drive.

"We don't know specifically what the exact mechanism of action is, but we believe it acts on brain chemicals that have a role in human sexual response," said Dr. Peter Piliero, executive director for Boehringer's U.S. medical affairs, in a report by the Associated Press. Since the launch of Viagra in 1998, more than two dozen experimental therapies have been studied for "female sexual dysfunction," a market which some analysts estimate at $2 billion.