Hair Loss Drug Finasteride Linked to Increased Suicide Risk, Study Finds
A new review by a public health expert at the Hebrew University of Jerusalem reveals that finasteride, a widely used treatment for hair loss, has been associated with depression and suicide for more than two decades. Despite these long-standing concerns, neither regulators nor the drug’s manufacturer took meaningful action. Drawing on adverse event reports and health records from several countries, the review identifies a consistent pattern of psychiatric side effects linked to the drug.
A History of Overlooked Risks
For over two decades, finasteride—a prescription drug taken by millions of men to treat hair loss—has carried troubling signals of deeper harm: depression, anxiety, and in some cases, suicide. Prof. Mayer Brezis of the Hebrew University of Jerusalem argues that both the medical community and regulators have repeatedly failed to protect the public by overlooking signs of psychiatric harm associated with the drug.
Consistent Findings Across Multiple Studies
The review, published in The Journal of Clinical Psychiatry, analyzed data from eight large studies conducted between 2017, and 2023. The findings show a clear trend: people who used finasteride were far more likely to experience mood disorders and suicidal thoughts than those who did not. This pattern appeared consistently across various national databases, including the FDA’s adverse event system and healthcare records from Sweden, Canada, and Israel.
“The evidence is no longer anecdotal,” said Prof. Brezis, a professor emeritus of medicine and public health. “We now see consistent patterns across diverse populations. And the consequences may have been tragic.”
Underreporting and Systemic Failure
The report estimates that hundreds of thousands of users may have suffered from finasteride-related depression, and that hundreds—possibly more—may have died by suicide. Although the FDA recognized depression as a possible side effect in 2011 and added suicidal thoughts to the label in 2022, researchers had been warning of potential dangers as early as 2002.
Internal FDA files from 2010 contained sections redacted as “confidential,” including estimates of how many people might have been affected. By 2011, only 18 suicides linked to finasteride had been reported to the FDA. Based on worldwide usage, Brezis concluded the actual number should have been in the thousands. “It wasn’t just underreporting,” Dr. Brezis wrote. “It was a systemic failure of pharmacovigilance.”
Classification and Lack of Scrutiny
Unlike drugs used to treat obesity or psychiatric disorders, which are often closely monitored after approval, finasteride’s classification as a cosmetic treatment may have shielded it from deeper scrutiny. None of the data-mining studies referenced in the review were initiated by Merck, the company that developed the drug, nor were they commissioned by regulatory authorities.
How Finasteride May Impact Mental Health
Brezis argues the drug’s classification as a non-essential, appearance-enhancing medication changes the risk calculus. “This wasn’t about life or death medical necessity,” he said. “This was about hair.”
Finasteride works by blocking the conversion of testosterone into dihydrotestosterone (DHT), but in doing so, it may likewise disrupt neurosteroids like allopregnanolone—linked to mood regulation in the brain. Animal studies have shown long-term effects on neuroinflammation and even changes in hippocampal structure.
Some patients report lingering symptoms—dubbed “post-finasteride syndrome”—including insomnia, panic attacks, cognitive dysfunction, and suicidal thoughts that persist months or even years after stopping treatment.
Calls for Regulatory Reform
Brezis is calling for immediate changes in how drugs like finasteride are approved, monitored, and prescribed. His recommendations include suspending marketing of the drug for cosmetic purposes until safety is re-established, mandatory post-approval studies with strict enforcement, and systematic recording of drug histories in suicide investigations.
“For many, those changes come too late. The paper is dedicated to one such individual—a previously healthy man who took finasteride “just” to improve his hair. Within days, he spiraled into severe psychiatric distress. He never recovered. Months later, he took his own life.”