Supplement
St. John's wort is a yellow-flowered herb whose extracts appear to act on brain chemistry, slowing the reuptake of messengers like serotonin, dopamine and norepinephrine so they stay active longer. Most people look at it for depression, and the evidence is strong: across three pooled analyses covering over 3,000 people, depression symptoms improved. Those results mainly concern mild to moderate depression, and the effect size was moderate rather than dramatic.
Sources: PMID 15684231; PMID 27468236
- Updated
- How we grade
- 3 studies cited
- Best evidence
- Grade A
- Conditions studied
- 1
- Outcomes
- 1
- Graded outcomes
- 1000
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Depression Symptoms Moderate Improvement | Improves (the measure goes down) | Moderate effect | 3 studies | 3,064 people | ||
Studies that measured depression symptoms | ||||||
Key findings
- Depression SymptomsImproves (the measure goes down)
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Third-party tested St. John's Wort products, in the forms the graded studies used where we can match them.
- Grade A
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Studies cited
3 studies from PubMed