Drug & supplement interaction

Feverfew + Warfarin Sodium

Warfarin Sodium brand names: Coumadin, Panwarfin, Sofarin.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Warfarin Sodium falls into 6 drug categories that Feverfew can interact with; the most serious is rated moderate. Theoretically, feverfew might increase levels of drugs metabolized by CYP2C19.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions6
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Feverfew and Warfarin Sodium

These two interact in 6 distinct ways. Each one is explained separately below.

Why Are There 6 Interactions?

Feverfew interacts with whole categories of medication. Warfarin Sodium falls into 6 of those categories, so it can interact with Feverfew in 6 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

1 of 6

Why this applies to Warfarin Sodium

Warfarin Sodium falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES — the group Feverfew interacts with.

Theoretically, feverfew might increase levels of drugs metabolized by CYP2C19.
Laboratory research shows that feverfew might inhibit CYP2C19. So far, this interaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist with warfarin: feverfew might slow down one of the liver enzymes (CYP2C19) that helps clear it. In theory, that could let a bit more warfarin linger in your system, nudging your blood toward being too thin. With warfarin that matters, because it's a narrow-window drug where even small shifts can mean easy bruising, nosebleeds, bleeding gums, or blood in your urine or stool.

I want to be honest, though: this is based only on lab research, and it hasn't actually been seen in people taking warfarin. So it's more of a caution flag than a proven problem. Before adding feverfew, please check with your pharmacist or doctor. They may simply want an extra INR check to keep you safe.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

2 of 6

Warfarin Sodium also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, feverfew might increase levels of drugs metabolized by CYP1A2.
Laboratory research shows that feverfew might inhibit CYP1A2. So far, this interaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist with feverfew and warfarin. Warfarin is an active blood thinner (not a prodrug), and part of how your body clears it runs through a liver enzyme called CYP1A2. In lab dishes, feverfew appears to slow that enzyme down. If that happened in real life, warfarin could build up a bit and thin your blood more than intended, which can show up as easy bruising, nosebleeds, bleeding gums, or blood in your urine or stool.

The reassuring part: this is only theoretical, seen in lab and animal studies, and it has never been reported in actual people. Still, warfarin has a narrow safe range, so even small shifts matter. Please check with your pharmacist or doctor before adding feverfew, and don't change your warfarin on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

3 of 6

Warfarin Sodium also falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES.

Theoretically, feverfew might increase levels of drugs metabolized by CYP2C9.
Laboratory research shows that feverfew might inhibit CYP2C9. So far, this interaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the basic idea with warfarin and feverfew. Your liver uses an enzyme called CYP2C9 to break down warfarin and keep its level steady. Lab studies suggest feverfew might slow that enzyme down a bit. If that happened in real life, warfarin could clear more slowly and build up, which could thin your blood more than intended. With warfarin, that can show up as easy bruising, nosebleeds, bleeding gums, or blood in your urine or stool.

The important part: this is only seen in test-tube and animal research, and it has never actually been reported in people. Still, warfarin is a touchy drug where small shifts matter, so please don't add feverfew without checking with your doctor or pharmacist first, who may want to watch your INR.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

4 of 6

Warfarin Sodium also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, feverfew might increase levels of drugs metabolized by CYP3A4.
Laboratory research shows that feverfew might inhibit CYP3A4. So far, this interaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version: lab tests hint that feverfew might slow down an enzyme called CYP3A4, which is one of the pathways your body uses to clear warfarin. In theory, that could let warfarin build up a bit and thin your blood more than intended. With a drug like warfarin, where the right dose sits in a narrow window, even small shifts can matter, raising the risk of easy bruising, nosebleeds, or more serious bleeding.

That said, this is only seen in laboratory studies, not in real people, so it's far from proven. I wouldn't panic over it, but warfarin is too important to guess with. Please check with your pharmacist or doctor before adding feverfew, especially since they may want to watch your INR more closely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  2. Sil'vestrov VP, Kinitin AV, and Chesnokova, IV. [Immunological and metabolic disorders and the means for their correction in patients with chronic bronchitis]. Ter.Arkh. 1991;63:7-11.
Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

5 of 6

Warfarin Sodium also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Theoretically, feverfew might have additive effects and increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.
Laboratory research suggests that feverfew may inhibit platelet aggregation. Additionally, in one case report, a 36-year-old patient taking feverfew 2400 mg daily for 3 months experienced vaginal bleeding and a prolonged menstrual cycle, with a modest increase in partial thromboplastin time (PTT) and prothrombin time (PT).
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for warfarin: feverfew may make your blood a little slower to clot on its own, possibly by affecting how platelets stick together. Stack that on top of warfarin, which is already thinning your blood, and the two could add up. That might nudge you toward easier bruising, nosebleeds, bleeding gums, or in rarer cases more serious bleeding.

I want to be honest about the strength of this, though. It's mostly theoretical, based on lab work and a single case report, not strong human studies. Still, warfarin is a finicky drug where small shifts matter, so don't add feverfew on your own. Have a quick chat with your pharmacist or doctor first, and watch for unusual bleeding if you do start it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Awang DVC. Prescribing therapeutic feverfew (Tancetum pathrnium (L.) Schultz Bip., syn. Chrysanthemumparthenium (L.) Bernh). Int Med 1998;1:11-3.
  2. Heptinstall S, Groenewegen WA, Spangenberg P, Loesche W. Extracts of feverfew may inhibit platelet behaviour via neutralization of sulphydryl groups. J Pharm Pharmacol 1987;39:459-65. PubMed
  3. Heptinstall S, White A, Williamson L, Mitchell JR. Extracts of feverfew inhibit granule secretion in blood platelets and polymorphonuclear leucocytes. Lancet 1985;1:1071-4. PubMed
  4. Makheja AN, Bailey JM. A platelet phospholipase inhibitor from the medicinal herb feverfew (Tanacetum parthenium). Prostaglandins Leukot Med 1982;8:653-60.
  5. Groenewegen WA, Heptinstall S. A comparison of the effects of an extract of feverfew and parthenolide, a component of feverfew, on human platelet activity in-vitro. J Pharm Pharmacol 1990;42:553-7. PubMed
  6. Heptinstall S, Groenewegen WA, Spangenberg P, Losche W. Inhibition of platelet behaviour by feverfew: a mechanism of action involving sulphydryl groups. Folia Haematol Int Mag Klin Morphol Blutforsch 1988;115:447-9.
  7. Biggs MJ, Johnson ES, Persaud NP, Ratcliffe DM. Platelet aggregation in patients using feverfew for migraine. Lancet 1982;2:776. PubMed
  8. Alenzi KA, Alharbi FH, Tawhari FM, Fradees GS. Alteration of Coagulation Test Results and Vaginal Bleeding Associated With the Use of Feverfew (Tanacetum parthenium). J Med Cases 2021;12(1):9-12.
Moderate

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES

6 of 6

Warfarin Sodium also falls under CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES.

Theoretically, feverfew might increase levels of drugs metabolized by CYP2C8.
Laboratory research shows that feverfew might inhibit CYP2C8. So far, this interaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist with warfarin and feverfew. Warfarin is partly cleared by a liver enzyme called CYP2C8, and lab studies hint that feverfew might slow that enzyme down. In theory, slowing it could let warfarin build up a bit, which would make your blood thinner than intended and could mean easier bruising, nosebleeds, bleeding gums, or in serious cases bleeding that's hard to stop.

I want to be honest about the strength of this, though. This concern comes only from test-tube and animal research, and it has never actually been reported in people. Still, warfarin is a finicky drug where even small shifts matter, so this is worth a quick heads-up to your pharmacist or doctor before adding feverfew. They may simply want to check your INR a little more closely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Feverfew Also Interacts With Other Medications

Feverfew has 928 moderate known drug interactions in our database — the Warfarin Sodium one above is among them. If you take anything else, check it against the full list below.

Moderate 928 No known interaction 1,902 (incl. Warfarin Sodium)
Taking anything else?

Check Another of Your Medications Against Feverfew

Covers the 2,830 medications we’ve checked against Feverfew. Pick one to open its full report.

From our Q&A

Questions About Feverfew or Warfarin Sodium

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Feverfew or Warfarin Sodium, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Warfarin Sodium

This page covers Feverfew only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Warfarin Sodium page lists 361 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Alfalfa (major), American Ginseng (major), Beer (major) and Cannabis (major).

Open the Warfarin Sodium interaction page

One more smart check

Taking Feverfew as Part of a Dietary Supplement Product? Check It for Interactions

We hold 520 real supplement products containing Feverfew, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Feverfew. Your product may carry other ingredients that interact with Warfarin Sodium too, on top of Feverfew — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Feverfew and Warfarin Sodium Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Feverfew
Top 25%

#329 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Warfarin Sodium
Top 1%

#20 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Feverfew

What is Feverfew?

Feverfew
  • Migraine prevention
  • Headache
  • Fever (traditional)
  • Arthritis and joint pain
  • Menstrual discomfort

Feverfew is a daisy-family herb best known for migraine prevention, where some studies suggest it may modestly lower how often migraines occur, though the evidence is mixed. It is generally well tolerated for short-term use in most adults but should be avoided during pregnancy and breastfeeding and by people allergic to ragweed and related plants. Talk to your pharmacist or doctor before starting it.

Read the full Feverfew monograph & all interactions
Medication

About Warfarin

What Is Warfarin Used For?

Brand names: Coumadin, Panwarfin, Sofarin

Warfarin sodium tablets and Jantoven tablets are both used to prevent and treat venous thrombosis (blood clots in the veins) and pulmonary embolism (a clot in the lungs). They are also used to prevent clot-related complications in people with atrial fibrillation (an irregular heart rhythm) or who have had a heart valve replaced.

In people who have had a heart attack, warfarin is used to reduce the risk of death, another heart attack, stroke, or other clotting events. It does not dissolve an existing clot, but it helps prevent the clot from growing and stops new dangerous clots from forming.

See full Warfarin drug information
Keep checking

Other Drugs & Feverfew

Browse every other medication we’ve checked against Feverfew — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
928Moderate
0Minor
1,901No known interaction
928 Moderate 1,901 No interaction
Moderate

928 interactions

Showing 60 of 928 moderate interactions — see all 928 on the Feverfew page.

No interaction 1,901 drugs checked — show the list

We also checked Feverfew against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,901 medications checked with no known interaction — see the full Feverfew list.

See the full Feverfew interactions page
See every supplement checked against Warfarin Sodium, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Feverfew monograph › Uses, safety, and every drug interaction in one place Warfarin Sodium supplement interactions › Every supplement checked against Warfarin Sodium, ranked by severity Warfarin drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Feverfew and Warfarin Sodium Together: Common Questions

Can you take Feverfew with Warfarin Sodium?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 6 interactions listed for Feverfew and Warfarin Sodium?
Warfarin Sodium belongs to more than one drug category, and Feverfew interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Feverfew and Warfarin Sodium interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

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

Still Have a Question About Warfarin Sodium and Feverfew?

Our pharmacists answer your medication & supplement questions — free.

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.