Does St. John's Wort help mood? (Grade B evidence)

Explore current source-reported research for this exact question. These records are separate from the synthesis below; they do not update its grade or establish a recommendation.

St. John's Wort probably helps mood (Grade B, moderate certainty), especially in adults, mild-to-moderate depression. Studied doses: 300 mg ×3/day.

Exact question reviewed

Population: adults, mild-to-moderate depression
Intervention: St. John's Wort · 300 mg ×3/day
Comparator: not reported
Outcome: mood
Time horizon: not reported

Bottom line. St. John's Wort probably helps mood (Grade B, moderate certainty), especially in adults, mild-to-moderate depression. Studied doses: 300 mg ×3/day. [2 other]

Direction: benefit
Magnitude: effective for mild-to-moderate depression in trials
Grade: B
Certainty: moderate
Clinical meaning: small but potentially useful
Who it applies to: adults, mild-to-moderate depression
Dose / form studied: 300 mg ×3/day
Safety: contraindicated_with_ssri
The one limitation: Claim-specific limitation details are not available in this public record.

Reviewed not reported · Evidence last changed 2026-07-16 · Open evidence record (version 0)

⚠ Safety in context

contraindicatedwith SSRI: St. John's Wort with an SSRI risks serotonin syndrome — do not combine. full interaction →

Grade

what does the grade mean?

Certainty

moderate

what does certainty mean?

Grade B / moderate: probably helps, and new studies are unlikely to reverse this — but could shrink the effect size.

Who it works for

Best-studied in adults, mild-to-moderate depression. Recorded studied dose: 300 mg ×3/day.

Evidence

Study	Design	Role	Cite
St John's wort for major depression	peer-reviewed	not classified	PMID:18843608 · DOI
A systematic review of St. John's wort for major depressive disorder.	peer-reviewed	not classified	PMID:27589952

Why this grade

Reasoning trace

The current record stores Grade B at moderate certainty and links 2 publishable sources. A claim-specific domain-by-domain grading rationale is not available in this public record, so no reason for upgrading or downgrading is inferred here.

Audit and version

Claim ID: ec_sjw_mood
Claim version: not reported
Governance: legacy, not verified
Clinician review: Not yet reviewed by a licensed clinician
Last evidence search: not reported
Last editorial review: not verified

Public receipt · Machine-readable claim · Methodology

Dose & form

Studied intake: 300 mg ×3/day.

How it stacks up for mood

St. John's Wort vs Vitamin D for mood — Vitamin D Grade C
St. John's Wort vs 5-HTP for mood — 5-HTP Grade C
St. John's Wort vs N-Acetylcysteine for mood — N-Acetylcysteine Grade C
St. John's Wort vs Saffron for mood — Saffron Grade B
St. John's Wort vs Folate for mood — Folate Grade —
St. John's Wort vs Vitamin C for mood — Vitamin C Grade —
All interventions graded for mood →

Grade history

2026-07-16B → BMerged additional source by Claude (gold-standard provenance sweep): a distinct, independently-verified paper ("A systematic review of St. J details →
2026-07-16B → BCorrection by Claude (gold-standard provenance sweep): live Postgres source drift replaced with the verified seed source set [pmid:18843608] details →

Re-review cadence: every 12 months (Grade A/B) · methodology v1.

Frequently asked

How long does St. John's Wort take to work for mood?

This record does not report a studied onset time for St. John's Wort and mood. Do not assume a typical timeframe.

What dose was used in studies of St. John's Wort for mood?

The recorded studied dose for St. John's Wort and mood is 300 mg ×3/day. This is a source detail, not a dose recommendation.

Does St. John's Wort work for mood if I'm not deficient?

The recorded studied population is adults, mild-to-moderate depression. This field alone does not show whether deficiency or baseline status changes the effect.

St. John's Wort or the next-best alternative for mood?

See the compare block above for the head-to-head with the most-cited alternative. Grade + certainty differences matter more than any single trial.

What this is — and is not

Evidence description: effective for mild-to-moderate depression in trials
Substrate's interpretation: The current reviewed record assigns Grade B at moderate certainty. A domain-by-domain rationale is shown only when recorded.
Discuss with a clinician: If you're on medication or have a condition that changes the calculus, bring the interaction & population blocks above to your pharmacist or prescriber before deciding.
Individualized medical advice: Not provided here or on any Substrate surface (API, agent tool, embed) — see YMYL policy.

Cite this page

Citation is encouraged. The proposed reuse license is CC-BY-4.0; status: pending-governance-ratification.

Plain-text citation

Substrate. Does St. John's Wort help mood? (Grade B). https://evidencebased.info/interventions/st-johns-wort/mood. Updated 2026-07-16.

BibTeX

@misc{substrate_tionsstjohnswortmood,
  author = {Substrate editorial},
  title  = {Does St. John's Wort help mood?},
  year   = {2026},
  url    = {https://evidencebased.info/interventions/st-johns-wort/mood},
  note   = {Grade B, evidencebased.info}
}

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Current source-reported research

Membership uses admitted intervention and measured-outcome associations for this exact question. Different populations, preparations, comparators and timepoints remain separate. No pooling or update to the synthesis is asserted.