A pharmaceutical company in the US is being sued by a law firm in Connecticut; the latter cites Procepia, a drug used to help cure hair loss as the reason for a man’s sexual dysfunction and mental health problems.

The law firm has combined its resources with two other law firms to take the well known pharmaceutical giant to court. They allege that the company failed in its duty of care to the man because it didn’t fully disclose potential side effects of using Procepia.

The drug at the heart of the case was originally approved for treating men with prostate problems. However research also found that it was useful for treating male pattern hair loss. Prostate patients found their hair re-grew. Seemingly, the drug’s active ingredient – finasteride – helps reduce levels of a particular chemical implicated in hair loss.

However other research shows that the same active ingredient can cause sexual dysfunction and anxiety. Lawyers say the pharmaceutical company that manufactures Procepia knew this but chose to ignore it. One of the lawyers told reporters: “The same mechanism in the hormone system that controls hair loss also controls sexual function and a patient’s mental state, and this drug has had devastating effects and destroyed the lives of men who have taken it.”

He added: “Merck knew this, and their claims that the negative effects of the drug go away once you stop using it are false. The damage to these men appears to be permanent, even after five years of taking the drug.”

For their part the company said: “The Company intends to vigorously defend against the lawsuit.”