The short answer
Avoid combining St. John’s wort with dabigatran etexilate unless your prescriber has arranged a different treatment plan. Product labeling identifies a risk of reduced anticoagulant exposure. Moving the supplement to another hour is not the recommended solution, and you should not stop the prescribed anticoagulant on your own.
What this answer covers
Oral Hypericum perforatum (St. John’s wort) products with adult oral dabigatran etexilate; exact extract composition varies.
- Supplement or preparation
- St. John’s wort
- Medication ingredient
- dabigatran etexilate
Why is this interaction important?
St. John’s wort induces P-glycoprotein, an intestinal transporter that can limit absorption of dabigatran etexilate. The European Pradaxa information explicitly names Hypericum perforatum and advises avoiding the combination because active dabigatran concentrations are expected to fall.
What does the label establish?
Dabigatran etexilate is the swallowed prodrug. The body converts it to dabigatran, which directly inhibits thrombin. The recommendation concerns reduced drug exposure and protection against clotting. It does not provide a universal percentage change for all St. John’s wort products or a randomized clinical event estimate for this exact supplement pair. The actionable recommendation is based on the named interaction and established transporter or enzyme pathway.
Can I take them several hours apart?
The prescribing information advises avoiding concomitant use rather than supplying a spacing interval. Altered transporter or enzyme activity is not limited to the moment two products reach the stomach. Tell the prescriber about recent starts, stops and product changes so the entire treatment plan can be assessed. Do not compensate with an extra anticoagulant dose.
What should happen if I already take both?
Contact your prescriber or pharmacist promptly and provide the St. John’s wort label, dose and duration. Discuss alternatives for the reason you take the herb while continuing the prescribed anticoagulation plan. A lack of bleeding does not show that dabigatran is working adequately, because the concern here is reduced protection against clots.
Evidence and practical considerations
Absorption & effectiveness
Avoid combining St. John’s wort with dabigatran etexilate unless your prescriber has arranged a different treatment plan. Product labeling identifies a risk of reduced anticoagulant exposure. Moving the supplement to another hour is not the recommended solution, and you should not stop the prescribed anticoagulant on your own.
- Exact scope
- Oral Hypericum perforatum (St. John’s wort) products with adult oral dabigatran etexilate; exact extract composition varies. with adult oral dabigatran etexilate mesylate capsules; active dabigatran produced after absorption
- Medication form and route
- adult oral dabigatran etexilate mesylate capsules; active dabigatran produced after absorption
- Timing or duration
- Concurrent oral use. Source-specific durations are recorded in the evidence entries; no unstudied duration threshold or separation schedule is inferred.
What remains uncertain
- Explicit label-supported avoidance; no exact product-specific exposure reduction or event rate established. No simple dose-spacing remedy. Botanical extract composition can vary.
Factors that may matter: Exact supplement preparation, dose and additional ingredients; Kidney function, age, bleeding history and other antiplatelet or anticoagulant medicines; Current medication formulation and recent supplement start or stop.
Read the supporting source summaries
Source 1: current U.S. regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients receiving oral dabigatran etexilate capsules.
P-gp induction reduces active dabigatran exposure. P-gp inhibition and impaired renal function increase exposure. Capsules must be swallowed intact. RE-LY trough concentrations were not appreciably changed by concomitant PPIs or H2 blockers.
How this applies: Establishes the exact medicine’s mechanism, baseline bleeding precautions and formulation/transport limitations; it does not establish this supplement-specific interaction. Exact scope: Oral Hypericum perforatum (St. John’s wort) products with adult oral dabigatran etexilate; exact extract composition varies.
Named medicine dose adjustments cannot be extrapolated to untested herbs. Label silence about a supplement does not prove compatibility. Capsule results must not be generalized to every formulation.
Source 2: current European regulatory prescribing information
ema.europa.eu · Source check Sep 10, 2026
Population: Patients taking oral dabigatran etexilate capsules.
The table explicitly identifies St. John’s wort as expected to decrease dabigatran concentrations and advises avoiding concomitant use.
How this applies: The current adult capsule interaction table explicitly names Hypericum perforatum. The subject is oral dabigatran etexilate with active dabigatran exposure as the pharmacokinetic outcome. Exact scope: Oral Hypericum perforatum (St. John’s wort) products with adult oral dabigatran etexilate; exact extract composition varies.
Label-supported expected interaction; this table does not provide a direct randomized St. John’s wort/dabigatran exposure or clinical event estimate.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Current labels and targeted original sources assessed; all current available claims adjudicated and consumer article prepared. Uncertainty and indirect evidence retained. Clinical sign-off not recorded. | |
| Research summary published |
Article revision: 21487bbb50eaa954
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.