Population-level risk of erectile dysfunction after finasteride use for androgenetic alopecia: a national cohort analysis

Finasteride 1 mg is widely prescribed for androgenetic alopecia (AGA), particularly among younger men seeking treatment for a chronic quality-of-life condition. Although sexual adverse effects, including erectile dysfunction (ED), are included in regulatory labeling, estimates of real-world risk remain heterogeneous, and population-level data specific to dermatologic finasteride use are limited.1 AGA is driven by androgen-mediated follicular miniaturization and has been associated with cardiometabolic risk factors overlapping with those contributing to ED, which is important when interpreting observed associations. Much of the existing epidemiologic literature focuses on urologic indications, where baseline sexual-function risk differs substantially from that of men treated for hair loss. Accordingly, these data are presented to describe population-level incidence patterns relevant to sexual-medicine counseling, in the setting of longstanding but heterogeneous reports of sexual adverse effects in the literature.2 To provide contemporary context, we examined the crude cumulative incidence of newly coded ED among men with AGA initiating finasteride compared with finasteride-untreated comparators using de-identified, aggregate data from the Epic COSMOS electronic health record (EHR) network.3 COSMOS integrates longitudinal EHR data across more than 180 US health systems. However, the platform captures only structured EHR data within participating systems and excludes external care settings and patient-reported outcomes. Analyses were conducted in exploration mode using aggregate data without patient-level records and were designed to estimate descriptive incidence patterns rather than causal effects.