It may not sound very familiar, but flibanserin is a drug that promises to improve the sexual lives of many people with vaginas. It is the most widely prescribed treatment for premenopausal female-assigned persons suffering from female sexual interest/arousal disorder (FSIAD, a disease category that is contested and criticised for pathologising and commercially exploiting people with low libido and asexuals). The prevalence rate of FSIAD lies somewhere between 6% and 46% in premenopausal female-assigned people; amongst their postmenopausal counterparts, it’s even 10% higher. Unfortunately, the drug is not very effective and causes significant side effects.

Flibanserin users reported on average 0.5 more satisfying sexual encounters per month. Sexual desire went up by 0.3 on a 5-point scale. These improvements, reported by a meta-analysis study, are marginal. The side-effects of flibanserin, by contrast, are significant: flibanserin users are 2 to 4 times more likely to experience dizziness, nausea and fatigue. Other side effects like low blood pressure, fainting and sleepiness have been reported too, but less frequently. Importantly, the chance of side effects goes up when users are on oral contraception or have consumed alcohol.

It is remarkable that flibanserin has been approved despite its marginal benefits and pervasive adverse side effects. In fact, the American Food and Drug Association (FDA) initially rejected the drug twice, in 2009 and 2013, because of lacking evidence of its effectiveness. In 2015, with no new benefit data, the drug suddenly did get approved (after which pharmaceutical company Sprout sold the drug to another company for 1 billion USD). The approval followed active campaigning by a coalition of women’s groups funded by Sprout and brought together by a Sprout consultant. Several other women’s advocacy groups also called for approval of the “pink Viagra”, stressing that the FDA had thus far only approved drugs that treat men’s sexual dysfunction.

The thing is, flibanserin is no Viagra. Viagra works on the genitals – it improves blood flow to the penis – whereas flibanserin works on the brain. More specifically, it works on serotonin, dopamine and norepinephrine, all three neurotransmitters that send signals between the brain and other body parts. Originally, flibanserin was developed as an anti-depressant but proved unsuccessful in trials. Some participants in these trials reported increased libido, which can be explained by the fact that much of the female sexual response cycle originates in the brain.

This is a reason to invest in research examining this relationship between the brain and sexual desire. It’s not a reason to approve a drug that simply isn’t effective enough. The women’s advocacy groups calling for approval rightly criticised the absence of drugs targeting FSIAD in female-assigned people. But female-assigned FSIAD patients shouldn’t be putting up with a flawed cure. Too often, drugs designed for female-assigned persons are ineffective or come with significant side effects – the primary example being virtually all forms of female contraception. We should denormalise the idea that female-assigned bodies are too “complex” and “mysterious” for, or simply not worthy of, appropriate medication.