Public health experts at the Hebrew University of Jerusalem in Israel recently issued a review report warning that a drug widely used to treat hair loss may pose serious mental health risks, and that regulatory authorities have not paid enough attention to it for many years. The report points out that finasteride, a common male hair loss treatment, has been linked to depression and suicide for more than two decades, but drug regulators and manufacturers have failed to take action.
Experts compiled global adverse drug event reports and medical databases to confirm a persistent link between finasteride and psychiatric side effects. Despite the growing evidence, neither Merck, the original drug manufacturer, nor the US FDA has launched a critical safety investigation. The authors of the report call for a comprehensive reform of the post-market supervision and evaluation system of drugs.
Finasteride is a prescription drug taken by millions of men around the world for hair loss, but its cosmetic use carries risks of anxiety, depression and even suicide. The review author, Professor Meyer Brezis of Hebrew University, cited data from eight large-scale studies between 2017 and 2023 and found that people who took the drug were much more likely to develop mood disorders or suicidal thoughts than those who did not take it. These results appear consistently in the US FDA Adverse Event Reporting System, Sweden, Canada, Israel and other health databases.
Professor Brezis said, "The evidence is no longer isolated. We can now see recurring trends in different groups, and the consequences can be extremely serious." It is estimated that hundreds of thousands of patients around the world may be depressed by finasteride, and hundreds or more of them may commit suicide as a result. The drug was approved by the FDA to treat male pattern baldness in 1997 and is still widely marketed to young men as a safe and effective solution. Critics say regulators have long ignored warning signs.
The U.S. FDA labeled depression as a side effect of the drug in 2011 and suicidal thoughts in 2022, but researchers had raised relevant concerns as early as 2002. Internal FDA documents cited in the Brezis report show that in 2010, part of the investigation was deleted due to "confidentiality," including an estimate of the number of users who might be affected. The FDA recorded only 18 suicides related to the drug in 2011, but estimates of global use put the number in the thousands. Brezis said this was not only underreporting, but also a complete failure of the drug control system.
Unlike weight-loss drugs or psychotropic drugs, finasteride, as a cosmetic drug, has not been strictly monitored after its launch. Neither the original research company nor the regulatory authorities have organized systematic data mining and safety research. Brezis pointed out that the non-essential, cosmetic nature of the drug led to a serious bias in the risk assessment. "This is not a life-or-death medical necessity, this is just hair loss."
The drug works by blocking the conversion of testosterone to dihydrotestosterone (DHT), but also affects neurosteroids such as fluprogesterone, which have been linked to mood regulation in the brain. Animal studies show that long-term use of the drug may lead to neuroinflammation and even structural changes in the hippocampus. Even after stopping the drug, some patients continue to experience symptoms such as insomnia, panic attacks, cognitive impairment and persistent suicidal thoughts, known as "post-finasteride syndrome."
The report severely criticized the FDA and Merck, arguing that both parties failed to take timely action. Companies have chosen to remain silent due to market and legal pressure, and regulatory authorities have not systematically conducted drug risk investigations. It took five years for the FDA to respond to public requests for black box warnings. In the end, it only added "suicidal tendencies" to the drug description without upgrading it to a formal warning.
Brezis suggested that the promotion of related drugs for cosmetic purposes should be suspended until their safety is re-confirmed, post-marketing safety studies should be mandatory, and medication history should be systematically recorded in suicide investigations. "For many people, these changes are already too late," he said. The paper was dedicated to commemorating a patient who fell into severe mental distress and ultimately committed suicide after taking finasteride to improve his hair style.
Compiled from /ScitechDaily