Adverse effects profile of the herbal antidepressant St. John's wort (Hypericum perforatum L.)

Ernst et al., 1998 | Eur J Clin Pharmacol | Systematic Review

Citation

Ernst E, Rand J I, ... Stevinson C. Adverse effects profile of the herbal antidepressant St. John's wort (Hypericum perforatum L.). Eur J Clin Pharmacol. 1998-Oct;54(8):589-94

Abstract

UNLABELLED: This paper provides a systematic review of adverse drug reactions (ADRs) associated with the use of extracts of the herb St. John's wort (Hypericum perfbratum L.) for the treatment of mild to moderate depression. METHODS: Searches of four computerized literature databases were performed for records of (ADRs). Manufacturers of hypericum products, the international drug monitoring centre of the World Health Organization (WHO) and the national drug safety monitoring bodies of Germany and the United Kingdom were also contacted for information. RESULTS: Information on (ADRs) originates from case reports, clinical trials, post-marketing surveillance and drug monitoring studies. Collectively, the data suggest that hypericum is well tolerated, with an incidence of adverse reactions similar to that of placebo. The most common adverse effects are gastrointestinal symptoms, dizziness/confusion and tiredness/sedation. A potential serious adverse effect is photosensitivity, but this appears to occur extremely rarely. CONCLUSIONS: Hypericum has an encouraging safety profile. However, as most of the current data originate from short-term investigations, more long-term studies are desirable.

Key Findings

Information on (ADRs) originates from case reports, clinical trials, post-marketing surveillance and drug monitoring studies. Collectively, the data suggest that hypericum is well tolerated, with an incidence of adverse reactions similar to that of placebo. The most common adverse effects are gastrointestinal symptoms, dizziness/confusion and tiredness/sedation. A potential serious adverse effect is photosensitivity, but this appears to occur extremely rarely.

Outcomes Measured

• depression

Population

MeSH Terms

• Antidepressive Agents
• Drug Monitoring
• Ericales
• Humans
• Photosensitizing Agents
• Plant Extracts
• Randomized Controlled Trials as Topic

Evidence Classification

• Level: Systematic Review
• Publication Types: Journal Article, Systematic Review
• Vertical: st.-john's-wort

Provenance

• PMID: 9860144
• DOI: (not available)
• PMCID: Not in PMC
• Verified: 2026-04-09 via PubMed E-utilities API

Source extracted via PubMed E-utilities API on 2026-04-09