Boehringer Ingelheim’s ‘female viagra’ flibanserin has suffered a massive setback across the pond after advisors to the US Food and Drug Administration rejected the drug on safety and efficacy concerns.

The FDA panel knocked back flibanserin after voting 10-1 that it is not effective in increasing female libido and unanimously ruling that its potential side effects, which include loss of consciousness and depression, are not acceptable given the limited benefit the drug offers.

The news comes as no big surprise, however, given that a review of the drug posted online ahead of the panel’s meeting on Friday concluded that it “failed to demonstrate a statistically significant improvement” in sexual desire in two trials, and that 15% of women stopped treatment because of side effects.

Boehringer is hoping to market flibanserin as a pill for Hypoactive Sexual Desire Disorder in pre-menopausal women, but the panel’s ruling means that this is now unlikely in the US unless the company stumps up additional data in favour of its clinical benefits.

In a statement, Christopher Corsico, medical director of Boehringer Ingelheim Pharmaceuticals, said the company is disappointed with the advisory committee's recommendations, “and will work with the FDA to address questions raised by the advisory committee”.

Just last month, the company published data from a clinical trial with 1,378 pre-menopausal women with HSDD which showed that, after 24 weeks, 48.3% of women receiving flibanserin and 30.3% on placebo reported feeling an improvement in sexual desire, and that more women taking the drug reported experiencing a meaningful benefit from the medication (40.5% versus 25.2%).