Drug & supplement interaction

Eicosapentaenoic Acid (epa) + Dicumarol

Dicumarol brand name: Dicumarol.

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

Eicosapentaenoic Acid (epa) has a moderate interaction with Dicumarol. Theoretically, EPA may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.

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

Eicosapentaenoic Acid (epa) and Dicumarol

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Dicumarol

Dicumarol falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Eicosapentaenoic Acid (epa) interacts with.

Theoretically, EPA may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In human research, taking EPA has been shown to inhibit platelet aggregation.
Severity Moderate Likelihood Possible Evidence B

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 is the thing to keep in mind. Dicumarol is a blood thinner that works by slowing down how your body uses vitamin K to form clots. EPA, the omega-3 from fish oil, does something a little different: in studies it makes your platelets (the cells that help stop bleeding) a bit less sticky. So you are not really speeding up or slowing down how dicumarol is broken down. Instead, you would have two things nudging you toward easier bleeding at the same time.

What might that look like? More bruising than usual, nosebleeds, bleeding gums, or cuts that take longer to stop. The evidence here is modest and the effect is usually mild, especially at food amounts of fish. Still, dicumarol is a drug we watch closely, so please check with your pharmacist or doctor before adding an EPA supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Terano T, Hirai A, Hamazaki T, et al. Effect of oral administration of highly purified eicosapentaenoic acid on platelet function, blood viscosity and red cell deformability in healthy human subjects. Atherosclerosis 1983;46:321-31.. 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

Eicosapentaenoic Acid (epa) Also Interacts With Other Medications

Eicosapentaenoic Acid (epa) has 288 moderate known drug interactions in our database — the Dicumarol one above is one of them. If you take anything else, check it against the full list below.

Moderate 288 No known interaction 2,542 (incl. Dicumarol)
Taking anything else?

Check Another of Your Medications Against Eicosapentaenoic Acid (epa)

Covers the 2,830 medications we’ve checked against Eicosapentaenoic Acid (epa). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Dicumarol

This page covers Eicosapentaenoic Acid (epa) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dicumarol page lists 218 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Danshen (major), Piracetam (major), Aconite (moderate) and Allspice (moderate).

By severity: 3 major · 190 moderate · 25 minor.

From our pharmacist’s overview on the Dicumarol page

“Danshen tops my worry list for anyone taking dicumarol, an older blood thinner in the warfarin family. It has clot-blocking activity of its own, and stacking it on an anticoagulant can push bleeding risk too far.”

Reviewed by 2 · Jul 18, 2026

Open the Dicumarol interaction page

How much people look this up

Where Eicosapentaenoic Acid (epa) and Dicumarol 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 Eicosapentaenoic Acid (epa)
Steady interest

#1,335 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Dicumarol
Steady interest

#1,959 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 Eicosapentaenoic Acid (epa)

What is Eicosapentaenoic Acid (epa)?

  • Heart and triglyceride health
  • Inflammation
  • Mood and depression support
  • Joint comfort
  • General omega-3 supplementation

EPA is an omega-3 fatty acid found mostly in fatty fish and fish oil, and it is best known for lowering high triglycerides. It may also help with inflammation and mood in some people, but evidence varies by condition. Talk with your pharmacist or doctor before starting, especially if you take blood thinners or have a fish allergy.

Read the full Eicosapentaenoic Acid (epa) monograph & all interactions
Keep checking

Other Drugs & Eicosapentaenoic Acid (epa)

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

0Major
288Moderate
0Minor
2,541No known interaction
288 Moderate 2,541 No interaction
Moderate

288 interactions

Showing 60 of 288 moderate interactions — see all 288 on the Eicosapentaenoic Acid (epa) page.

No interaction 2,541 drugs checked — show the list

We also checked Eicosapentaenoic Acid (epa) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,541 medications checked with no known interaction — see the full Eicosapentaenoic Acid (epa) list.

See the full Eicosapentaenoic Acid (epa) interactions page
See every supplement checked against Dicumarol, 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
Eicosapentaenoic Acid (epa) monograph › Uses, safety, and every drug interaction in one place Dicumarol supplement interactions › Every supplement checked against Dicumarol, ranked by severity 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 Eicosapentaenoic Acid (epa) and Dicumarol Together: Common Questions

Can you take Eicosapentaenoic Acid (epa) with Dicumarol?
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.
How serious is the Eicosapentaenoic Acid (epa) and Dicumarol 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 Dicumarol and Eicosapentaenoic Acid (epa)?

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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.