To evaluate the association between long-term finasteride use and incident benign prostatic hyperplasia (BPH) and prostate cancer (PCa) diagnosis. Low-dose finasteride (1mg) is widely prescribed for androgenic alopecia, often via telemedicine, resulting in prolonged use in men without baseline prostatic disease. While higher-dose finasteride is studied for BPH and PCa prevention, urologic outcomes of chronic low-dose use remain unclear.
In this retrospective cohort study using the TriNetX Research Network, adult men with androgenic or nonscarring alopecia and no prior BPH or PCa were included. Exposure cohorts were defined by continuous finasteride 1mg use for ≥3 or ≥5 years and compared to alopecia controls without finasteride. Cohorts were matched 1:1 via propensity scores for demographics, comorbidities, labs, medications, and healthcare utilization. Time-to-event analyses used Kaplan-Meier and Cox models, with hazard ratios (HRs) as the primary measure.
After matching, 6,741 patients per group comprised the 3-year cohort and 4,534 per group the 5-year cohort. At three years, finasteride was associated with lower BPH (HR 0.64, 95% CI 0.55-0.75) and PCa diagnosis (HR 0.49, 95% CI 0.33-0.74). At five years, finasteride was associated with lower BPH (HR 0.52, 95% CI 0.43-0.63) and PCa diagnosis (HR 0.47, 95% CI 0.28-0.79). Patterns were consistent for symptomatic and asymptomatic BPH. Absolute PCa diagnosis rates remained low.
In men treated for alopecia, long-term low-dose finasteride was associated with reduced incident BPH and PCa diagnosis. Prospective studies are needed to clarify mechanisms and long-term clinical implications.
Urology. 2026 Apr 23 [Epub ahead of print]
Robert Adler, Michael Kozlov, Juliana Viola, Justin Ingram, Karl-Ray Jeune, Jessica Lori Feig, Andrew Winer, Jeffrey P Weiss
State University of New York Downstate Health Sciences University, College of Medicine. Electronic address: ., State University of New York Downstate Health Sciences University, College of Medicine., Department of Urology, State University of New York Downstate Health Sciences University, Brooklyn, NY., Department of Dermatology, State University of New York, Downstate Health Sciences University, Brooklyn, NY, USA; Dermatology Service, Veterans Affairs New York Harbor Healthcare System - Brooklyn Campus, Brooklyn, NY., Department of Urology, State University of New York Downstate Health Sciences University, Brooklyn, NY; Urology, Veterans Affairs New York Harbor Healthcare System - Brooklyn Campus, Brooklyn, NY.