The short answer
Avoid St. John’s wort with rivaroxaban unless your prescriber has specifically addressed the interaction. The current prescribing information advises avoiding this combination, and a human study found reduced rivaroxaban exposure and anticoagulant effect. Taking the products a few hours apart is not an established solution.
What this answer covers
Adult oral rivaroxaban with oral Hypericum perforatum, also called St. John’s wort. Direct studies used specified hyperforin-containing extracts; other products cannot be assigned the same numerical effect.
- Supplement or preparation
- Hypericum perforatum
- Medication ingredient
- rivaroxaban
How can St. John’s wort affect rivaroxaban?
Certain St. John’s wort extracts increase the activity of enzymes and transporters that influence how much rivaroxaban reaches the bloodstream. Lower exposure can weaken its protection against clots. The current rivaroxaban label specifically names St. John’s wort among combinations to avoid. The clearest concern is reduced treatment effect, rather than a demonstrated rise in rivaroxaban levels or a quantified increase in bleeding.
What evidence supports the interaction?
In 12 healthy adults, two weeks of Jarsin extract at 450 mg twice daily reduced exposure to a single 20 mg rivaroxaban dose by about 24%. The measured anticoagulant effect also fell by about 20%. An earlier study found a similar exposure reduction, although participants were also taking macitentan. Neither study measured long-term stroke or clotting outcomes in patients, so those event rates cannot be calculated from these results.
Do the extract or timing change the advice?
Hyperforin content differs between St. John’s wort products, so the exact size of the interaction may vary. The tested preparations cannot establish that an untested product is safe. Enzyme and transporter induction develops during repeated use; shifting one dose to a different hour does not address that mechanism reliably. The label’s avoidance advice should not be replaced with an improvised spacing schedule or a self-directed rivaroxaban dose increase.
What if I already take both?
Contact your prescriber or pharmacist promptly with the product name, strength, daily amount and start date. They can decide how to replace or discontinue the supplement and whether the anticoagulant plan needs assessment. Keep taking rivaroxaban as prescribed while obtaining advice, because stopping it prematurely also increases clot risk. Any change in St. John’s wort use should be communicated so the medication review reflects your actual exposure.
Evidence and practical considerations
Absorption & effectiveness
Avoid St. John’s wort with rivaroxaban unless your prescriber has specifically addressed the interaction. The current prescribing information advises avoiding this combination, and a human study found reduced rivaroxaban exposure and anticoagulant effect. Taking the products a few hours apart is not an established solution.
- Exact scope
- Adult oral rivaroxaban with oral Hypericum perforatum, also called St. John’s wort. Direct studies used specified hyperforin-containing extracts; other products cannot be assigned the same numerical effect. with adult oral rivaroxaban tablets
- Medication form and route
- adult oral rivaroxaban tablets; oral supplement
- Timing or duration
- Direct exposure reduction after 14 days of Jarsin 450 mg twice daily; supporting study after 12 days of Jarsin 300 mg three times daily with macitentan coexposure.
What remains uncertain
- Small healthy-volunteer pharmacokinetic studies do not quantify stroke, thrombosis or bleeding rates in patients. Extract composition matters; no safe hourly spacing interval or universal dose correction was demonstrated.
Factors that may matter: Exact supplement formulation, composition and daily dose; Kidney function, indication, bleeding history and concurrent medicines; Recent supplement initiation or discontinuation.
Read the supporting source summaries
Source 1: current U.S. regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People using oral rivaroxaban for approved indications.
Avoid combined P-gp/strong CYP3A inducers including St. John’s wort. Rivaroxaban can cause serious bleeding, and premature discontinuation increases thrombotic risk. Adult 15 mg and 20 mg doses are taken with food.
How this applies: Exact rivaroxaban ingredient and oral formulation. Direct named applicability to Hypericum perforatum avoidance; medication-only context for ginkgo and vitamin E. Exact article scope: Adult oral rivaroxaban with oral Hypericum perforatum, also called St. John’s wort. Direct studies used specified hyperforin-containing extracts; other products cannot be assigned the same numerical effect.
General bleeding precautions are not proof that every supplement increases rivaroxaban bleeding. The label does not supply a ginkgo- or vitamin E-specific effect size or safe spacing interval.
Source 2: peer-reviewed prospective human pharmacokinetic and pharmacodynamic study
bpspubs.onlinelibrary.wiley.com · Source check Sep 10, 2026
Population: 12 healthy adults, mean age 25 years, 10 women; open-label, nonrandomized sequential study.
Rivaroxaban exposure fell 24% (AUC ratio 0.76, 90% CI 0.70-0.82) and integrated anti-factor Xa effect fell 20% (ratio 0.80, 0.71-0.89). Enzyme/transporter probe results supported CYP3A4/P-gp induction.
How this applies: Direct support for reduced rivaroxaban exposure and measured anticoagulant effect with a specified hyperforin-containing oral extract. Other formulations and clinical event rates remain uncertain; current label avoidance governs practical advice. Exact article scope: Adult oral rivaroxaban with oral Hypericum perforatum, also called St. John’s wort. Direct studies used specified hyperforin-containing extracts; other products cannot be assigned the same numerical effect.
One extract, small healthy sample, single rivaroxaban doses and no patient thrombotic outcome estimate. Partly supported by Bayer. One participant received ciprofloxacin during the first rivaroxaban session. Suggested platelet effects in the discussion were not proof of a clinical bleeding interaction.
Source 3: peer-reviewed prospective human pharmacokinetic study
bpspubs.onlinelibrary.wiley.com · Source check Sep 10, 2026
Population: 12 healthy volunteers completed a one-sequence study; 14 initially enrolled.
Compared with rivaroxaban plus macitentan before induction, rivaroxaban exposure fell approximately 25% after St. John’s wort (AUC ratio 0.75, 90% CI 0.68-0.84).
How this applies: An additional exact-pair signal under explicit macitentan coexposure, consistent with the separate 2021 study. It is not treated as an unconfounded two-product trial. Exact article scope: Adult oral rivaroxaban with oral Hypericum perforatum, also called St. John’s wort. Direct studies used specified hyperforin-containing extracts; other products cannot be assigned the same numerical effect.
Small healthy sample, macitentan coadministration and fasting administration of 20 mg rivaroxaban limit direct translation to current fed adult dosing. This is not a clinical clotting or bleeding outcome trial.
Research assessment: · Open full citations ↗
Timing & monitoring
The rivaroxaban label advises avoiding St. John’s wort. No hourly separation schedule or self-directed dose adjustment is established to overcome this interaction.
- Exact scope
- Adult oral rivaroxaban with oral Hypericum perforatum, also called St. John’s wort. Direct studies used specified hyperforin-containing extracts; other products cannot be assigned the same numerical effect. with adult oral rivaroxaban tablets
- Medication form and route
- adult oral rivaroxaban tablets; oral supplement
- Timing or duration
- Direct exposure reduction after 14 days of Jarsin 450 mg twice daily; supporting study after 12 days of Jarsin 300 mg three times daily with macitentan coexposure.
What remains uncertain
- Small healthy-volunteer pharmacokinetic studies do not quantify stroke, thrombosis or bleeding rates in patients. Extract composition matters; no safe hourly spacing interval or universal dose correction was demonstrated.
Factors that may matter: Exact supplement formulation, composition and daily dose; Kidney function, indication, bleeding history and concurrent medicines; Recent supplement initiation or discontinuation.
Read the supporting source summaries
Source 1: current U.S. regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People using oral rivaroxaban for approved indications.
Avoid combined P-gp/strong CYP3A inducers including St. John’s wort. Rivaroxaban can cause serious bleeding, and premature discontinuation increases thrombotic risk. Adult 15 mg and 20 mg doses are taken with food.
How this applies: Exact rivaroxaban ingredient and oral formulation. Direct named applicability to Hypericum perforatum avoidance; medication-only context for ginkgo and vitamin E. Exact article scope: Adult oral rivaroxaban with oral Hypericum perforatum, also called St. John’s wort. Direct studies used specified hyperforin-containing extracts; other products cannot be assigned the same numerical effect.
General bleeding precautions are not proof that every supplement increases rivaroxaban bleeding. The label does not supply a ginkgo- or vitamin E-specific effect size or safe spacing interval.
Source 2: peer-reviewed prospective human pharmacokinetic and pharmacodynamic study
bpspubs.onlinelibrary.wiley.com · Source check Sep 10, 2026
Population: 12 healthy adults, mean age 25 years, 10 women; open-label, nonrandomized sequential study.
Rivaroxaban exposure fell 24% (AUC ratio 0.76, 90% CI 0.70-0.82) and integrated anti-factor Xa effect fell 20% (ratio 0.80, 0.71-0.89). Enzyme/transporter probe results supported CYP3A4/P-gp induction.
How this applies: Direct support for reduced rivaroxaban exposure and measured anticoagulant effect with a specified hyperforin-containing oral extract. Other formulations and clinical event rates remain uncertain; current label avoidance governs practical advice. Exact article scope: Adult oral rivaroxaban with oral Hypericum perforatum, also called St. John’s wort. Direct studies used specified hyperforin-containing extracts; other products cannot be assigned the same numerical effect.
One extract, small healthy sample, single rivaroxaban doses and no patient thrombotic outcome estimate. Partly supported by Bayer. One participant received ciprofloxacin during the first rivaroxaban session. Suggested platelet effects in the discussion were not proof of a clinical bleeding interaction.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Current prescribing information and targeted original sources assessed; current claims adjudicated individually and consumer article written. Exact preparations, conflicting or indirect findings and unresolved limits retained. Clinical sign-off not recorded. | |
| Research summary published |
Article revision: 2adfb8429dc1db91
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.