Finasteride and Mental Health: The Overlooked Psychiatric Risks of a Popular Hair-Loss Drug
A comprehensive review by Professor Mayer Brezis reveals alarming evidence linking the widely used hair-loss medication finasteride to depression, anxiety, and suicide. Despite decades of warnings and consistent patterns across multiple national health databases, regulatory bodies and the drug manufacturer failed to take meaningful action. The analysis exposes systemic failures in pharmacovigilance and calls for urgent reforms in how cosmetic medications are approved and monitored for long-term safety risks.
The popular hair-loss medication finasteride, prescribed to millions of men worldwide, has been associated with serious psychiatric side effects for over two decades. Despite mounting evidence linking the drug to depression, anxiety, and suicide, regulatory authorities and the pharmaceutical manufacturer have consistently failed to address these safety concerns adequately. A recent comprehensive review by Professor Mayer Brezis of the Hebrew University of Jerusalem exposes this troubling pattern of inaction and calls for immediate regulatory reforms to protect public health.
The Evidence: Consistent Patterns Across Multiple Studies
Professor Brezis's review analyzed data from eight major studies published between 2017 and 2023, drawing from diverse sources including the FDA's adverse event reporting system and healthcare records from Sweden, Canada, and Israel. The findings reveal a clear and consistent pattern: individuals using finasteride were significantly more likely to experience mood disorders and suicidal thoughts compared to those not taking the medication. This consistency across different populations and healthcare systems suggests the psychiatric risks are genuine and widespread.
The biological mechanism behind these psychiatric effects appears well-established. Finasteride works by inhibiting the conversion of testosterone to dihydrotestosterone (DHT), but this process also disrupts neurosteroids like allopregnanolone, which play crucial roles in mood regulation. Animal studies have demonstrated that these disruptions can lead to long-term neuroinflammation and structural changes in the hippocampus, a brain region critical for emotional processing.
Regulatory Failures and Corporate Inaction
Despite early warnings dating back to 2002, neither Merck (the drug's manufacturer) nor the FDA initiated comprehensive safety investigations. The FDA eventually recognized depression as a possible side effect in 2011 and added suicidal thoughts to the drug label in 2022, but these actions came years after substantial evidence had accumulated. Internal FDA documents from 2010 contained redacted sections marked as "confidential," including estimates of how many individuals might have been affected by these adverse effects.
The classification of finasteride as a cosmetic treatment may have contributed to the lack of rigorous post-marketing surveillance. Unlike medications for life-threatening conditions, cosmetic drugs often receive less scrutiny despite their widespread use among healthy populations. Professor Brezis argues this represents a fundamental failure in risk assessment, stating, "This wasn't about life or death medical necessity. This was about hair."
The Human Cost and Lingering Effects
The review estimates that hundreds of thousands of finasteride users may have experienced depression related to the medication, with hundreds—possibly more—dying by suicide. Perhaps most concerning are reports of "post-finasteride syndrome," where symptoms including insomnia, panic attacks, cognitive dysfunction, and suicidal thoughts persist for months or even years after discontinuing the drug.
Professor Brezis's paper includes a dedication to one such individual—a previously healthy man who took finasteride solely to improve his appearance. Within days of starting the medication, he developed severe psychiatric distress that never resolved, ultimately leading to his suicide months later. This tragic case exemplifies the devastating potential consequences that extend far beyond the drug's intended cosmetic purpose.
Call for Regulatory Reform
The review concludes with urgent recommendations for systemic change. Professor Brezis calls for suspending marketing of finasteride for cosmetic purposes until safety can be re-established, implementing mandatory post-approval studies with strict enforcement, and systematically recording medication histories in suicide investigations. These measures would help prevent similar failures in the future and ensure that medications—even those classified as cosmetic—receive appropriate safety monitoring.
The case of finasteride highlights critical gaps in our pharmaceutical regulatory system and underscores the need for more robust pharmacovigilance, particularly for medications used by healthy individuals for non-essential purposes. As Professor Brezis emphasizes, "The evidence is no longer anecdotal. We now see consistent patterns across diverse populations. And the consequences may have been tragic."
This situation serves as a sobering reminder that all medications carry risks, and that regulatory systems must remain vigilant in monitoring these risks—especially when drugs are used by millions of people for conditions that don't threaten their physical health. The lessons from the finasteride experience should inform future drug approval and monitoring processes to better protect public health.
