Post-Finasteride Syndrome: A Review of the Clinical Evidence

This page summarizes the published clinical evidence base specifically for Post-Finasteride Syndrome (PFS) — the constellation of persistent sexual, neuropsychological, and physical adverse effects reported by a subset of men after stopping finasteride.

Key Evidence Landmarks

Year	Publication/Event	Key contribution
2011	Traish AM et al. case series	First systematic case series documenting persistent sexual and neurological symptoms after stopping finasteride in men who previously had no prior sexual dysfunction
2012	FDA Propecia/Proscar label update	Official regulatory acknowledgment that sexual adverse effects may persist after discontinuation
2014	Melcangi RC et al.	Documented reduced neuroactive steroid levels (including allopregnanolone and 5α-androstane-3α,17β-diol) in PFS patients vs. controls
2017	Melcangi RC et al. J Steroid Biochem	Further neuroactive steroid profiling + psychiatric symptom documentation in Italian PFS cohort
2019	EMA PRAC review and label update	European prescribing information updated to include depression and suicidal ideation as adverse effects
2020	Khera M et al. / PFS Foundation	Registry-based analysis documenting range and severity of persistent symptoms; highlighted need for standardized PFS diagnostic criteria
2022	Giatti S et al. (epigenetic study)	Epigenetic changes in androgen receptor gene methylation in rodent models after finasteride; proposed mechanism for persistent post-treatment effects

Evidence Quality Assessment

• Existence of PFS: Well-supported by case series, registry data, FDA and EMA regulatory actions, and biologically plausible mechanisms. Evidence level: moderate-high for existence of the phenomenon.
• Frequency: Not established. No prospective population-level incidence study has been completed. Evidence level: insufficient.
• Mechanism: Multiple proposed (neurosteroid, epigenetic AR, peripheral neurological); none conclusively established in humans. Evidence level: hypothesis-generating, not confirmatory.
• Treatment: No RCT-supported treatment exists. Evidence level: insufficient.

Full clinical guide: Post-Finasteride Syndrome: Symptoms, Evidence, and Research

Sources

• Traish AM, et al. “Adverse effects of 5α-reductase inhibitors: what do we know, don’t know, and need to know?” Rev Urol. 2011;13(3):130–145.
• Melcangi RC, et al. “Neuroactive steroid levels are modified in cerebrospinal fluid and plasma of post-finasteride patients.” J Sex Med. 2013;10(10):2598–2603.
• European Medicines Agency. PRAC recommendations on signals. November 2019.