Introduction Finasteride has been associated with reversible adverse sexual side effects in multiple randomized, controlled trials for the treatment of male pattern hair loss (MPHL). The Medicines and Healthcare Products Regulatory Agency of the United Kingdom and the Swedish Medical Products Agency have both updated their patient information leaflets to include a statement that “persistence of erectile dysfunction after discontinuation of treatment with Propecia has been reported in post-marketing use.” Aim We sought to characterize the types and duration of persistent sexual side effects in otherwise healthy men who took finasteride for MPHL. Methods We conducted standardized interviews with 71 otherwise healthy men aged 21–46 years who reported the new onset of sexual side effects associated with the temporal use of finasteride, in which the symptoms persisted for at least 3 months despite the discontinuation of finasteride. Main Outcome Measures The types and duration of sexual dysfunction and the changes in perceived sexual frequency and sexual dysfunction score between pre- and post-finasteride use. Results Subjects reported new-onset persistent sexual dysfunction associated with the use of finasteride: 94% developed low libido, 92% developed erectile dysfunction, 92% developed decreased arousal, and 69% developed problems with orgasm. The mean number of sexual episodes per month dropped and the total sexual dysfunction score increased for before and after finasteride use according to the Arizona Sexual Experience Scale (P <0.0001 for both). The mean duration of finasteride use was 28 months and the mean duration of persistent sexual side effects was 40 months from the time of finasteride cessation to the interview date. Study limitations include a post hoc approach, selection bias, recall bias for before finasteride data, and no serum hormone levels. Conclusion Physicians treating MPHL should discuss the potential risk of persistent sexual side effects associated with finasteride.

Phytoestrogens are hormonally active compounds present in plant foods that are being studied extensively for their potential roles in hormonally-sensitive neoplasms such as prostate cancer. We postulate that the evidence for a protective role of phytoestrogens is not conclusive enough for a general recommendation for their use as dietary supplements, but phytoestrogens can be considered for therapeutic use in prostate cancer patients under certain circumstances. A literature review was performed to study the evidence regarding the chemopreventive role of phytoestrogens in healthy men, the protective role in early prostate cancer, and a possible therapeutic role in advanced prostate cancer patients. Dietary supplementation with phytoestrogens for chemoprevention of prostate cancer is still a debatable subject. Numerous pre-clinical in vitro studies have been promising, and novel molecular mechanisms of action for phytoestrogens continue to be identified. However, human clinical trials including studies done on prostate biomarkers and on the effects of phytoestrogens on steroid hormones are complicated by the possibility of local paracrine effects in prostatic tissue by phytoestrogens that are steroid-like in structure. Their interaction with multiple enzymes represents a paradigm for the complexity of phytoestrogen effects and a window into a potential reason that study results are inconsistent or difficult to explain. A final outcome of the phytoestrogen effect in the intact human may be difficult to discern because these agents can inhibit or induce enzymes, destroy cancer cells, yet will have intrinsic estrogenic effects themselves. Larger multi-center, multi-national, randomized controlled trials are needed before definitive recommendations can be made on the usefulness of phytoestrogens for chemoprevention and therapy for prostate cancer. However, combinations of phytoestrogens with radiation therapy and other antioxidants in advanced or metastatic prostate cancer can be considered because there are limited effective therapy options for this group of patients.