Can we identify a post-Serenoa syndrome (PSS)? A case series on sexual and psychiatric side effects of Serenoa repens.

Serenoa repens is widely used for benign prostatic hyperplasia and androgenetic alopecia due to its 5alpha-reductase inhibitory activity. However, emerging reports describe sexual, psychiatric and somatic adverse effects resembling a post-finasteride syndrome. Cases were identified from self-reports submitted to an Italian online forum dedicated to post-finasteride syndrome. All individuals underwent structured clinical evaluation at the CERFIT centre, including medical and psychiatric history, symptom assessment and available laboratory data. Reports were documented using the official Italian pharmacovigilance forms (www.vigierbe.it), and causality was independently assessed by two clinicians using the Naranjo Scale. Reported doses ranged from 120-900 mg/day, with adverse effects emerging within 1 month in 61% of cases. Symptoms were severe and persistent (mean duration 4.7 years), with complete remission in only three patients. According to the Naranjo Scale, causality was deemed 'probable' in 54% of reports; combined therapies (e.g., S. repens plus finasteride) were associated with increased severity and persistence. A possible post-Serenoa syndrome marked by persistent sexual and neuropsychiatric symptoms may represent an underestimated issue. Misbelief in the absolute safety of S. repens likely hinders reporting. Given its widespread, unsupervised use, further pharmacovigilance and clinical studies are warranted.