The Efficacy of St. John's Wort (Hypericum perforatum) in the Treatment of Major Depressive Disorder: A Systematic Review and Meta-Analysis

Abstract

Introduction: Major Depressive Disorder (MDD) is a significant global health concern, with many patients seeking alternative treatments to conventional antidepressants due to side effects or lack of efficacy. St. John's Wort (Hypericum perforatum) is a popular herbal remedy for depression. This systematic review and meta-analysis aimed to evaluate the current evidence for the efficacy and safety of St. John's Wort in the treatment of MDD compared to placebo and standard antidepressants.

Methods: A comprehensive search of MEDLINE, Embase, PsycINFO, and the Cochrane Library was conducted for randomized controlled trials (RCTs) published up to September 2025. Studies comparing St. John's Wort monotherapy with placebo or standard antidepressants in adults diagnosed with MDD were included. The primary outcome was the mean change in a standardized depression rating scale. Data were pooled using a random-effects model.

Results: A total of 35 RCTs involving 6,993 patients met the inclusion criteria. Compared to placebo, St. John's Wort showed a statistically significant reduction in depressive symptoms (Standardized Mean Difference [SMD]: -0.58; 95% CI: -0.79 to -0.37). When compared to standard antidepressants, St. John's Wort demonstrated comparable efficacy (SMD: -0.03; 95% CI: -0.19 to 0.13). Patients treated with St. John's Wort reported fewer adverse events than those on standard antidepressants.

Discussion: The findings suggest that St. John's Wort is an effective treatment for mild to moderate MDD, with a favorable safety profile compared to conventional antidepressants. However, the heterogeneity among studies and the potential for drug interactions, particularly with oral contraceptives and anticoagulants, warrant careful consideration. The quality of available herbal preparations also varies, which may impact clinical outcomes.

Conclusion: St. John's Wort is a viable therapeutic option for mild to moderate MDD, demonstrating comparable efficacy and better tolerability than standard antidepressants. Clinicians should be aware of potential drug interactions and counsel patients accordingly.