The US Food and Drug Administration (FDA) has rejected a request to pull the anti-baldness drug Propecia (finasteride) tablets and its generic versions off the market.

In 2017, Post-Finasteride Syndrome Foundation, a patient advocacy group has urged the US FDA to either stop Merck & Co. from selling the drug or require far stronger warnings.

Their claims were based on various scientific studies, reported Reuters.

The US regulator for the first time required a patient notification about reports of suicidal behaviour in men taking the drug.

The US FDA has previously approved an expanded label indication for Propecia to include risks of persistent sexual dysfunction and depression, but it did not mention suicide.

Merck spinoff Organon said it stands behind the safety and efficacy of Propecia and is working with the US health regulator to take the best measures.

Merck was informed of more than 200 reports of depression and suicidal thoughts in men taking Propecia, through its internal risk management assessment, from 2009, reported Reuters.

In 2011, the US FDA declined to add a warning related to suicide but has ultimately agreed with Merck that the suicide toll was reduced in this patient group.

The US regulator was quoted by the publication as saying: “The group’s petition does not provide reasonable evidence of a causal link between Propecia and persistent sexual problems, depression or suicide.

“However, based on patient reports, the FDA said it is requiring the addition of suicidal ideation and behaviour to the adverse reactions listed on Propecia’s label.”

Since then, the US regulator has received more than 700 reports of suicide and suicidal thoughts among people taking versions of finasteride, said the publication.

Regulatory authorities in Europe and Canada require a warning of suicidal thoughts on the finasteride label, citing similar reports among men taking the drug.