For millions of men, finasteride has been marketed as a simple solution to hair loss.
Approved by the U.S. Food and Drug Administration (FDA) in 1997, the drug promised to slow or even reverse male pattern baldness.
But beneath its cosmetic appeal, a growing body of research has revealed a troubling reality: finasteride is consistently linked to depression, anxiety, and even suicide.
A new review led by Professor Mayer Brezis of the Hebrew University of Jerusalem argues that both drug regulators and the pharmaceutical industry failed to act on mounting evidence of psychiatric harm.
The review, published in The Journal of Clinical Psychiatry, analyzed eight major studies conducted between 2017 and 2023. Across different populations and health systems—including data from Sweden, Canada, Israel, and the U.S.—the results were strikingly similar.
Men who took finasteride were significantly more likely to experience mental health problems than those who did not.
“The evidence is no longer anecdotal,” said Brezis. “We now see consistent patterns across diverse populations. And the consequences may have been tragic.”
According to his analysis, hundreds of thousands of men worldwide may have developed depression linked to the drug, and hundreds—or possibly more—may have died by suicide.
Despite these risks, official warnings lagged far behind. The FDA acknowledged depression as a possible side effect in 2011, but only added suicidal thoughts to the label in 2022. By then, the drug had already been on the market for 25 years.
Internal FDA documents from 2010 revealed that whole sections, including estimates of how many patients might have been affected, were blacked out as “confidential.” Critics argue this delay in transparency came at a high cost.
One reason for the slow response, Brezis suggests, is that finasteride was categorized as a cosmetic drug. Unlike life-saving medicines, its main purpose was to improve appearance. That status may have shielded it from the kind of rigorous monitoring applied to weight-loss or psychiatric medications.
The biological explanation for finasteride’s risks is becoming clearer. The drug works by blocking the hormone dihydrotestosterone (DHT), which drives hair loss. But in the process, it also interferes with brain chemicals known as neurosteroids, including one called allopregnanolone that helps regulate mood.
Animal studies show these disruptions can cause long-term changes in brain function.
Some men report that symptoms such as insomnia, panic attacks, memory problems, and suicidal thoughts persist long after they stop taking the drug—a condition known as “post-finasteride syndrome.”
Brezis believes regulators and drug companies must be held accountable. He is calling for stronger warnings, mandatory long-term safety studies, and even suspending the marketing of finasteride for cosmetic use until its safety can be firmly established.
For some patients, however, these changes will come too late. Brezis dedicated his paper to one man who took finasteride “just” to improve his hair, only to suffer an immediate and irreversible spiral into psychiatric distress. Within months, he ended his life.
The story serves as a stark reminder: when it comes to medicine, even drugs marketed as low-risk can carry life-altering consequences.
