Article Impact Level: HIGH Data Quality: STRONG Summary of Frontiers in Pharmacology, 16, 1609605. https://doi.org/10.3389/fphar.2025.1609605 Dr. Rachael Frost et al.
Points
- An extensive review found that while omega-3s, St John’s Wort, and saffron have the most evidence for depression, most other supplements have only been studied in single trials.
- Herbal supplements, such as lavender and lemon balm, alongside nutrients like folic acid and zinc, show promising initial results but require further research before they can be officially recommended.
- Although generally safe, some supplements like St John’s Wort can interact dangerously with prescription antidepressants, potentially causing severe conditions such as serotonin syndrome if combined improperly.
- The effectiveness of many supplements is complicated by significant variations in quality, active ingredient dosage, and formulation, making it difficult for consumers to establish consistent results and recommendations.
- Pharmaceutical medications and psychological therapies remain the gold-standard treatments for depression due to a more extensive evidence base, though lifestyle interventions like diet and exercise are also effective.
Summary
A recent scoping review aimed to assess the evidence base for over-the-counter (OTC) products in treating depression in adults aged 18–60. Following the Joanna Briggs Institute’s guidance, researchers searched five major databases, including MEDLINE and CENTRAL, from their inception to December 2022. From an initial 23,933 records, 1,367 full texts were screened, resulting in the inclusion of 209 randomised controlled trials (RCTs). The review did not report specific confidence intervals or hazard ratios for individual outcomes.
The most significant volume of evidence was identified for omega-3s, St John’s Wort, saffron, probiotics, and vitamin D. Among a range of herbal medical products, lavender, lemon balm, chamomile, and Echium were noted as warranting further research based on promising evidence and everyday use. However, the evidence base is thin for most products, with 41 supplements having only single trials available for analysis. Few safety issues were identified for products used either as monotherapy or adjunctively with prescription antidepressants.
The authors concluded that products with limited but promising evidence, including folic acid, lavender, zinc, tryptophan, Rhodiola, and lemon balm, should be prioritized for future research. They recommend further evaluation of herbal products as adjuncts to both antidepressants and psychological therapies to support a more integrative approach to care. A call was also made for significant improvements in the standards of safety reporting within future clinical trials in this field.
Link to the article: https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1609605/full
References Frost, R., Zamri, A., Mathew, S., Salame, A., Bhanu, C., Bhamra, S. K., Bazo-Alvarez, J. C., Heinrich, M., & Walters, K. (2025). Understanding the research landscape of over-the-counter herbal products, dietary supplements, and medications evaluated for depressive symptoms in adults: A scoping review. Frontiers in Pharmacology, 16, 1609605. https://doi.org/10.3389/fphar.2025.1609605
