Supplement evidence

090 / 575Mood & stress

St. John’s wort

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The short answer

Standardized extracts can improve mild-to-moderate depressive symptoms, but interaction risk is unusually high.

Evidence and scope: Supported for specific outcomes
This status does not grade the ingredient for every goal, outcome, or person.
Important limitation: Evidence supports a specific outcome, not a general wellness or longevity effect.
Before deciding: Key concern: Do not combine with antidepressants, birth control, transplant, HIV, anticoagulant, seizure, cancer, or many other medicines.

01 / PRACTICAL GUIDE

Dose, absorption, and combinations

These are indication-specific reference or studied ranges—not a personalized prescription. Start with the objective, then check the form, label, medicines, and health conditions.

Reference range by objective

Mood symptomsAbout 300 mg standardized extract three times daily in many trials

Reference or studied range—not a personalized prescription. The product label or a clinician may specify a different dose.

Dose source ↗

More is not automatically better. A clinician or product label may specify a different amount.

Absorption / solubilityFormulation-dependent

Not usefully classified as a fat- or water-soluble vitamin; absorption depends on the salt, extract, delivery system, and meal.

How it is commonly taken

Use only a standardized product and clinician/pharmacist interaction review.

Do not combine casually

Do not combine with antidepressants, birth control, transplant, HIV, anticoagulant, seizure, cancer, or many other medicines.

Dose and use source ↗

Dose and use links lead to primary or official source material. Search links are discovery tools, not proof that every returned paper applies.

02 / EVIDENCE

What the research says

We keep supportive, mixed, negative, safety, and contextual findings together. The headline never replaces the underlying papers.

2research papers in this ledger

35unique primary studies represented

6,993unique participants represented

These are audited counts for this JIVANA collection, not search-result totals. Participants are counted once when multiple papers use the same cohort; review papers are not added again to participant totals.

Open the research timelineResearch timeline

Entries are ordered by publication year. A study period appears only when the source reports it.

2016

Mixed or qualifiedPMID 27589952 · PROSPERO CRD42015016406

A systematic review of St. John's wort for major depressive disorder

St. John's wort produced more responders than placebo and similar outcomes to antidepressants in mild-to-moderate depression, with fewer reported adverse events. High heterogeneity, sparse severe-depression evidence, poor rare-event reporting, and extract differences constrain use.

Published: 2016n=6,993 participants35 primary studies represented

Study design and methods

Design: Systematic review and meta-analysis of 35 randomized trials
Population: 6,993 adults with major depressive disorder, mainly mild to moderate
Intervention: St. John's wort monotherapy for at least 4 weeks versus placebo or antidepressants
Outcome: Depression response, symptom scores, adverse events, and comparative effectiveness

Open research record ↗

2016

Safety signalPMID 27444983

Co-administration of St. John's wort and hormonal contraceptives

Evidence showed more breakthrough bleeding, reduced hormone exposure, and a concern for ovulation and reduced contraceptive efficacy. This safety review is not added to efficacy study or participant totals.

Published: 2016

Study design and methods

Design: Systematic review of 4 clinical or pharmacokinetic comparative studies
Population: Women of reproductive age using combined oral contraceptives
Intervention: Hormonal contraceptive with versus without St. John's wort
Outcome: Ovulation markers, breakthrough bleeding, and contraceptive hormone exposure

Funding or conflict note: CDC-supported review; authors declared no conflicts.

Open research record ↗

Unscreened discovery appendix—not evidence86 candidate publicationsSearch run: Aug 21, 2026

Complete for the displayed PubMed query at the search timestamp—not for all databases or every possible synonym. Candidates can be irrelevant, duplicate the same study, or report negative findings. They are never summed as evidence or participants until screened.

03 / SOURCES

Start with the source material

Official evidence overviewPubMed bounded human-evidence search Live PubMed discovery searchNational Library of Medicine

The live search is for discovery only. Search-result counts change and are not included in the audited totals above.

Recent PubMed discovery recordsDirect links to the first 12 records returned by the reproducible search. These are discovery candidates—not reviewed summaries or a count of supportive findings.

04 / EXPERT CONTEXT

Expert context—not evidence

Expert positions are dated context—not scientific evidence. They never raise the evidence status or become consensus by repetition.

No direct, source-verified endorsement is currently recorded. Research authorship or discussion alone is not treated as endorsement.