It has been dubbed the “female Viagra” and this week it became the first drug for treating loss of libido in women to win approval in the US.

The decision by the Food and Drug Administration was hailed as a victory by feminist campaigners who lobbied to put the medicine on the market – but it was also deeply divisive.

Many in the medical establishment are sceptical about the drug’s effectiveness and argue its approval raises questions about the regulator’s ability to withstand “patient power” in the age of social media.

Flibanserin, marketed under the brand name Addyi, is a drug with a chequered history. It was developed as an antidepressant in the 1990s by Boehringer Ingelheim, the large German pharmaceuticals group, but failed to make it through clinical trials.

Higher sex drive

Although it did not prove effective in treating depression, researchers noticed that the drug elicited a higher sex drive in some patients, prompting Boehringer to switch focus.

The drug was sold to privately owned Sprout Pharmaceuticals after the FDA refused to approve the drug for hypoactive sexual desire disorder – a loss of libido that cannot be explained by relationship problems, mental health issues, medication or illness. Sprout too failed to get the green light in 2013, but was third time lucky.

Some doctors are asking what prompted the FDA to change its stance, having turned down the drug twice before. One change was a high-profile campaign on social media, which styled Sprout’s attempt to secure the drug’s approval as a fight for female equality and accused some of its detractors of misogyny. – Copyright The Financial Times Limited 2015