Drug & supplement interaction

Feverfew + Diclofenac Potassium

Diclofenac Potassium brand names: Voltaren Rapide, Cataflam, Cataflam IR, Voltarol Rapid, Cambia.

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

Diclofenac Potassium falls into 2 drug categories that Feverfew can interact with; the most serious is rated moderate. Theoretically, feverfew might increase levels of drugs metabolized by CYP2C9.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Feverfew and Diclofenac Potassium

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Feverfew interacts with whole categories of medication. Diclofenac Potassium falls into 2 of those categories, so it can interact with Feverfew in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

1 of 2

Why this applies to Diclofenac Potassium

Diclofenac Potassium falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Feverfew interacts with.

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 gist: your body relies on a liver enzyme called CYP2C9 to break down diclofenac. In lab studies, feverfew appears to slow that same enzyme down. In theory, if diclofenac is cleared more slowly, a bit more of it could linger in your system, which might nudge up the usual side effects of this kind of pain reliever, such as stomach upset, heartburn, or in rare cases stomach irritation or bleeding.

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 real people. So it's more of a theoretical caution than a proven problem. Still, if you're considering feverfew for migraines while taking diclofenac, it's worth a quick chat with your pharmacist or doctor first.

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

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 2

Diclofenac Potassium 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 you: diclofenac (Cataflam, Voltaren) is an NSAID, and like other drugs in that family it can make your blood a little slower to clot and can be hard on the stomach lining. Feverfew, in lab studies, seems to make platelets (the cells that help you clot) less sticky. Put the two together and you could, in theory, raise your odds of bleeding or bruising more easily.

I want to be honest about how strong this is: the concern comes mostly from laboratory work and a single case report, so it's more theoretical than proven. Still, NSAIDs already carry a bleeding risk, so it's worth a quick mention. Watch for unusual bruising, nosebleeds, or dark stools, and check with your pharmacist or doctor before pairing them, especially with concentrated feverfew supplements.

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.

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 Diclofenac Potassium 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. Diclofenac Potassium)
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 Diclofenac Potassium

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 Diclofenac Potassium, 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 Diclofenac Potassium

This page covers Feverfew only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diclofenac Potassium page lists 306 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Piracetam (major).

Open the Diclofenac Potassium 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 Diclofenac Potassium 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 Diclofenac Potassium 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%

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

29 days ago today
Medication Diclofenac Potassium
Top half

#1,198 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 Diclofenac

What Is Diclofenac Used For?

Brand names: Voltaren Rapide, Cataflam, Cataflam IR, Voltarol Rapid, Cambia

Diclofenac sodium topical gel is used to treat actinic keratoses (AK) — rough, scaly skin patches that form after years of sun exposure. These patches are considered precancerous, meaning they can develop into skin cancer if left untreated.

This is a topical gel, meaning it is applied directly to the skin over the affected area rather than taken by mouth. It belongs to the NSAID (nonsteroidal anti-inflammatory drug) family.

See full Diclofenac 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 Diclofenac Potassium, 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 Diclofenac Potassium supplement interactions › Every supplement checked against Diclofenac Potassium, ranked by severity Diclofenac 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 Diclofenac Potassium Together: Common Questions

Can you take Feverfew with Diclofenac Potassium?
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 2 interactions listed for Feverfew and Diclofenac Potassium?
Diclofenac Potassium 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 Diclofenac Potassium 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 Diclofenac Potassium and Feverfew?

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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.