Medication interaction hub

What Supplements Interact with Warfarin?

Warfarin brand names: Warfarin, Coumadin, Panwarfin, Sofarin. Every interaction below applies to the brands too.

361 Interactions 16 Major 301 Moderate 44 Minor
Curated & coded by · Clinical Pharmacist · Updated September 24, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Warfarin? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Warfarin against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

People take warfarin to prevent dangerous clots, and many are the same people reaching for glucosamine for sore joints or a multivitamin containing vitamin K, which makes this a list that deserves genuine respect. Of the 361 supplements on file for warfarin, 16 carry a major rating, and the danger runs in both directions: some add to warfarin's blood-thinning effect and raise bleeding risk, while others, vitamin K and St. John's wort among them, blunt it and let clotting risk creep back.

Most of the 301 moderate entries follow the same pattern, either nudging bleeding risk upward or changing how the liver processes warfarin, which can push its blood level up or down. Consistency matters as much as avoidance; even a shift in vitamin K intake can unsettle a stable dose. The 16 major entries are the ones to understand first, and anything else on this page merits a conversation with your pharmacist before it goes in the cart.

— , Clinical Pharmacist · July 18, 2026

Major 16 Moderate 301 Minor 44 No known interaction 1,091

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Top Ingredient Interactions

Warfarin: Top Interactions at a Glance

The most significant Warfarin supplement & herbal interactions, colored by severity. Tap any ingredient to open the full report for that pair.

Showing the 12 highest-ranked of 361 interacting ingredients — plus 1,091 more checked with no known interaction. See the complete ranked list.

Start here

The Major Interactions to Know About

The most clinically significant Warfarin + supplement combinations in our database, best-documented first. Open any card for the full report.

Major Likelihood Likely American Ginseng + Warfarini

American ginseng seems to decrease the effectiveness of warfarin therapy.

Read the full interaction Major Likelihood Likely Grapefruit + Warfarini

Grapefruit juice can increase levels of drugs metabolized by CYP3A4.

Read the full interaction Major Likelihood Likely St. John's Wort + Warfarini

St.

Read the full interaction Major Likelihood Likely Vitamin K + Warfarini

Vitamin K can antagonize and reverse the therapeutic effects of warfarin.

Read the full interaction Major Likelihood Probable Activated Charcoal + Warfarini

Activated charcoal reduces systemic exposure to many drugs, including those that undergo enterohepatic recirculation, regardless of the route of administration.

Read the full interaction Major Likelihood Probable Alfalfa + Warfarini

Theoretically, alfalfa might reduce the anticoagulant activity of warfarin.

Read the full interaction
The complete list

Every Supplement Checked Against Warfarin

All 1,452 ingredients in our database, ranked by severity — 361 with a Warfarin interaction on file and 1,091 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Warfarin?

One-line answers, one card per combination — scroll through today’s 20 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take Glucosamine with Warfarin?

Major Use real caution — this is a major-rated interaction, generally best avoided or used only under close supervision. Glucosamine might increase the anticoagulant effects of warfarin and increase the risk of bruising and bleeding.

Full Glucosamine + Warfarin answer

Can you take Tangerine with Warfarin?

Minor Usually — this is a minor-rated interaction, generally not clinically significant but worth mentioning to your pharmacist. In vitro, tangeretin, a constituent of tangerine, induces a 52% increase in the metabolism of midazolam by cytochrome P450 3A4 (CYP3A4).

Full Tangerine + Warfarin answer

Can you take Devil's Claw with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, devil's claw might increase levels of drugs metabolized by CYP2C19.

Full Devil's Claw + Warfarin answer

Can you take Dhea with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, DHEA might increase the levels of drugs metabolized by CYP3A4.

Full Dhea + Warfarin answer

Can you take Dimethylsulfoxide (dmso) with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, DMSO might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.

Full Dimethylsulfoxide (dmso) + Warfarin answer

Can you take Diosmin with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, diosmin might inhibit the metabolism of CYP2C9 substrates.

Full Diosmin + Warfarin answer

Can you take Echinacea with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Echinacea might inhibit the metabolism of CYP1A2 and increase plasma levels of some drugs.

Full Echinacea + Warfarin answer

Can you take Eicosapentaenoic Acid (epa) with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, EPA may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.

Full Eicosapentaenoic Acid (epa) + Warfarin answer

Can you take Eleuthero with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, eleuthero might increase levels of drugs metabolized by CYP1A2.

Full Eleuthero + Warfarin answer

Can you take English Ivy with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, English ivy might increase the levels of drugs metabolized by CYP2C19.

Full English Ivy + Warfarin answer

Can you take Ephedra with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, ephedra might decrease levels of drugs metabolized by CYP1A2.

Full Ephedra + Warfarin answer

Can you take Eucalyptus with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, eucalyptus might increase the levels of CYP2C19 substrates.

Full Eucalyptus + Warfarin answer

Can you take European Barberry with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, European barberry might increase the levels and clinical effects of CYP3A4 substrates.

Full European Barberry + Warfarin answer

Can you take European Buckthorn with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. European buckthorn has stimulant laxative effects, which can cause diarrhea in some people.

Full European Buckthorn + Warfarin answer

Can you take Evening Primrose with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.

Full Evening Primrose + Warfarin answer

Can you take False Unicorn with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. In vitro, false unicorn extract inhibits cytochrome P450 3A4 (CYP3A4) activity.

Full False Unicorn + Warfarin answer

Can you take Fennel with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, fennel might increase levels of drugs metabolized by CYP3A4.

Full Fennel + Warfarin answer

Can you take Fenugreek with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, fenugreek might have additive effects with warfarin and increase the international normalized ratio (INR).

Full Fenugreek + Warfarin answer

Can you take Feverfew with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, feverfew might increase levels of drugs metabolized by CYP2C19.

Full Feverfew + Warfarin answer

Can you take Flaxseed with Warfarin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, using flaxseed in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of b...

Full Flaxseed + Warfarin answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Warfarin is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Warfarin, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Warfarin sits in 10 interaction categories. Open any one to see what the group means:

Anticoagulant/Antiplatelet Drugs 202 ingredients

Blood-thinning medications. Supplements with their own effects on clotting or platelets can add up with these drugs and raise bleeding risk.

202 of the supplement ingredients on this page reach Warfarin through this category.

Cytochrome P450 3A4 (Cyp3A4) Substrates 121 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

121 of the supplement ingredients on this page reach Warfarin through this category.

Warfarin (Coumadin) 100 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

100 of the supplement ingredients on this page reach Warfarin through this category.

Cytochrome P450 1A2 (Cyp1A2) Substrates 79 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

79 of the supplement ingredients on this page reach Warfarin through this category.

Cytochrome P450 2C9 (Cyp2C9) Substrates 64 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

64 of the supplement ingredients on this page reach Warfarin through this category.

Cytochrome P450 2C19 (Cyp2C19) Substrates 33 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

33 of the supplement ingredients on this page reach Warfarin through this category.

Oral Drugs 17 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

17 of the supplement ingredients on this page reach Warfarin through this category.

Cytochrome P450 2C8 (Cyp2C8) Substrates 11 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

11 of the supplement ingredients on this page reach Warfarin through this category.

Cytochrome P450 1A2 (Cyp1A2) Substrates 1 ingredient

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

1 of the supplement ingredient on this page reaches Warfarin through this category.

Warfarin 1 ingredient

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

1 of the supplement ingredient on this page reaches Warfarin through this category.

About Warfarin

Warfarin is a blood thinner used to prevent and treat blood clots in veins, lungs, and the heart.

Generic name: Warfarin  ·  Brand names: Warfarin, Coumadin, Panwarfin, Sofarin.

See the full Warfarin drug information
Check a real product

Take a Supplement Product? Check the Whole Bottle Against Warfarin

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Warfarin.

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Pharmacist Counseling Corner

Warfarin & Supplements: Common Questions

What supplements interact with Warfarin?
More than you might expect — 361 in total, though they are far from equal: 16 are rated major, 301 moderate, and 44 minor. The ranked list on this page puts the ones that genuinely matter first, and every entry opens a full report on that exact pair. The highest-ranked right now: American Ginseng, Grapefruit, St. John's Wort.
Which Warfarin supplement interactions are the most serious?
Focus on the major group: American Ginseng, Grapefruit, St. John's Wort, Vitamin K and Activated Charcoal, among others. A major rating means the combination can be clinically significant, not that harm is guaranteed — but it's exactly the kind of thing to run past your pharmacist before your next dose, not after. Jump to the ranked list.
Can I take vitamins or supplements while on Warfarin?
Usually yes — most people on Warfarin can take most supplements. The catch is the exceptions, and they aren't always the exotic ones (St. John's Wort trips up more prescriptions than almost anything sold next to it). Look up each ingredient you actually take in the list above, and treat "no known interaction" as a green-ish light, not a guarantee. Try the label scanner or the interaction checker.
Do brands like Warfarin have the same supplement interactions as Warfarin?
Yes — Warfarin, Coumadin, Panwarfin, Sofarin all contain Warfarin, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
What about Warfarin and my other medications?
This page covers Warfarin against supplements and herbal ingredients. Checking Warfarin against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker, or read the full Warfarin drug information.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of September 24, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.