Effect of St. John’s Wort (<i>Hypericum perforatum</i> L.) on Male Sexual and Reproductive Health: A Narrative Review

Background: Hypericum species are widely acknowledged for their biological attributes, with notable attention being paid to <i>Hypericum perforatum</i>, commonly known as St. John’s wort (SJW) within the Hypericum section of the Hypericaceae family. This species is among the most thoroughly investigated herbal medicines, particularly in terms of its application in the management of mild to moderate depression. SJW is used to treat depression, menopausal symptoms, attention-deficit hyperactivity disorder (ADHD), somatic symptom disorder, obsessive–compulsive disorder, and skin conditions, such as wounds and muscle pain. However, the usefulness and effectiveness of SJW for male sexual and reproductive health (SRH) are not well known. Objective: To assess the current evidence in the literature on the effect of SJW on male SRH. Methods: This narrative review followed a predetermined protocol and used MEDLINE and PubMed to identify articles published in English on the effects of SJW on male SRH. The search used various keywords, such as “<i>Hypericum Perforatum</i>”, “St. John’s Wort”, and terms related to sexual and reproductive health issues. Articles published between the inception of the database and August 2023 were included. Results: We identified 12 articles published from 1999 to 2019, the majority of which were experimental and conducted on animals. These studies demonstrate variability in terms of design, sample size, type of SJW extract used, the dosage administered, and duration of treatment. Studies have indicated potential sexual dysfunction (SD) due to SJW, which includes reduced libido, delayed ejaculation, delayed orgasm, and erectile dysfunction. Additionally, reproductive toxicity has been suggested, as evidenced by spermicidal effects through the inhibition of sperm motility, abnormal spermatozoa, chromosomal aberrations, and DNA denaturation. Furthermore, some studies have reported potential adverse events during maternal exposure, inhibition of fertilization, and disruption of reproductive parameters. Conclusions: Our review suggests that the safety and efficacy of SJW in the treatment of human SRH remain unclear. Further comprehensive, well-designed studies with larger samples, longer exposure periods, and specific dosages are needed to clarify SJW's effects of SJW. Therefore, consultation with healthcare professionals before using herbal remedies or supplements is crucial.