The European drugs regulator said it was reviewing anti hair-loss drugs, including Organon's Propecia and its generic versions, over the risks of suicidal thoughts.

The European Medicines Agency said it would recommend whether the marketing authorizations for the drugs should be withdrawn, suspended or maintained across the region following its review.

Oral anti-baldness drugs called finasteride and dutasteride have a known risk of psychiatric side effects. Finasteride, branded as Propecia, already comes with warnings about the risk of suicidal thoughts.

A patient advocacy group, the Post-Finasteride Syndrome Foundation, petitioned the FDA in 2017 to order Merck to either stop selling the drug or add far stronger warnings, citing several scientific studies.

Several years later in 2022, the FDA rejected a request to remove Propecia from the market and ordered a warning about suicidal thoughts and behavior on the drug's label.

Anti-baldness drugs are sold under the brand name Propecia, from Organon, and Avodart by British drugmaker GSK, but also have generic versions available in the market.

Organon, which was spun-off from Merck in 2021, and GSK did not immediately respond to a request for comment.