The latest attempt at a drug to rev up the female sex drive may have failed, according to a US Food and Drug Administration (FDA) report released this morning.

Flibanserin, made by Boehringer Ingelheim, is under evaluation for the treatment of low sex drive in women who have not yet reached menopause. The FDA report, part of the briefing materials prepared for an advisory committee meeting Friday, concludes that although women taking the drug reported more sexually satisfying experiences, they showed no statistically significant increase in sexual desire.

Boehringer’s report for the advisory committee acknowledges that desire was only significantly enhanced in one of three trials of the drug, but notes “positive trends” in the other two. Those taking the drug also consistently scored better on the ‘Female Sexual Function Index – Desire Items’, an assessment of sexual desire over 28 days, leading Boehringer to conclude that “flibanserin is more consistently effective in increasing women’s global experience of desire than in increasing the intensity of their acute episodes of desire”. (The FDA, however, noted that the sexual function index may be susceptible to ‘recall bias’.)

The FDA has yet to make a final decision on the drug, but it seems that for some women, a boost in the “global experience of desire” wasn’t worth the side effects: women on the drug had an increased risk of constipation, fainting, and, strangely enough, appendicitis. In total, 15% of subjects taking flibanserin dropped out of the study.