Rivaroxaban and St. John's Wort: what the published research says
PubMed indexes 2 records that name Rivaroxaban and St. John's Wort together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.
Every statement below is attributed to a named, dated, linked source.
This page lists published research relevant to Rivaroxaban and St. John's Wort. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.
A study appearing here is not proof that an interaction exists. Two substances can be named together in a paper that never tested them in combination, and a source listed as background may cover only one of them.
Findings are quoted from each abstract as the authors wrote them. NutriStack has not re-analysed, pooled, or reconciled them, and they may disagree with each other.
NutriStack’s own interaction assessment for this pair is not published here. It has not completed qualified-human clinical review, so it is withheld from search. See the publication gate.
Nothing here is medical advice. Decisions about prescription medication and supplements belong with your prescriber or pharmacist, who can see your full regimen.
The research
2 studies naming Rivaroxaban and St. John's Wort.
Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.
British journal of clinical pharmacology · 2018 · PMID 30192025
Clinical Trial, Phase I
“There is no evidence for a relevant pharmacokinetic interaction between macitentan and rivaroxaban suggesting that these two drugs can be combined without dose adjustment. SJW strongly increased CYP3A activity and substantially reduced rivaroxaban and macitentan exposure while estimated net endothelin antagonism only decreased by 20%, which is considered clinically irrelevant. The combination of SJW with rivaroxaban should be avoided.”
Names both Rivaroxaban and St. John's Wort in its title.
British journal of clinical pharmacology · 2021 · PMID 32959922
Human subjects
“The CYP3A4/P-gp inducing H. perforatum extract caused a decrease of rivaroxaban exposure with a proportional decrease of the pharmacodynamic effect. Although the data do not justify a contraindication for the combination or a systematic adjustment of rivaroxaban dosage, avoidance of the combination or laboratory monitoring should be considered in patients taking hyperforin-containing H. perforatum extracts with rivaroxaban.”
Names both Rivaroxaban and St. John's Wort in its title.
Limitations
What this evidence cannot tell you.
Search-based evidence indexes have real limits, and it is worth being explicit about them:
Selection. These records were found by searching PubMed titles and abstracts for both substance names alongside interaction and pharmacokinetic terms. Relevant work that phrases things differently, or is not indexed in PubMed, will be missing.
No effect size. The quoted conclusions are the authors’ words about their own study. We have not extracted effect direction or magnitude, and a single study’s conclusion is not a consensus.
Population mismatch. Findings in healthy volunteers, animals, or a specific patient group may not transfer to you, your dose, or your formulation.
Absence is not safety. Few published studies means the combination is under-studied, which is not the same as established as safe.
Nearby evidence
Other pairs with published research.
Pages covering Rivaroxaban or St. John's Wort alongside a different substance.
NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Rivaroxaban, St. John's Wort, and several hundred other substances.
The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.
NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.
