Drug & supplement interaction

Ketogenic Diet + Warfarin Sodium

Warfarin Sodium brand names: Coumadin, Panwarfin, Sofarin.

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

Ketogenic Diet has a minor interaction with Warfarin Sodium. Although there is some concern that the ketogenic diet might have additive effects when used with anticoagulant and antiplatelet drugs, most clinical research does not show this effect.

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

Ketogenic Diet and Warfarin Sodium

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

Minor

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Warfarin Sodium

Warfarin Sodium falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Ketogenic Diet interacts with.

Although there is some concern that the ketogenic diet might have additive effects when used with anticoagulant and antiplatelet drugs, most clinical research does not show this effect.
One small observational study found that the ketogenic diet was associated with prolonged bleeding times in 16 of 51 (31%) children with epilepsy who were also on chronic anticonvulsant therapy. However, a larger observational study of 162 children with epilepsy taking chronic anticonvulsants has found that following the ketogenic diet does not increase the risk of bleeding, even in the 25 children undergoing surgery. Research in adults also has not reported changes in bleeding time.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the honest picture with warfarin and a ketogenic diet: the worry is that very low-carb, high-fat eating could add to warfarin's blood-thinning and raise the chance of bleeding (think easy bruising, nosebleeds, or bleeding that's slow to stop). But most studies don't actually back that up. A small study saw longer bleeding times in some children, while larger studies in both kids and adults found no real increase in bleeding. So this is a minor, unlikely concern.

Still, warfarin is a finicky drug where small shifts matter, and big diet changes can affect your INR. If you're thinking about starting keto, give your pharmacist or doctor a heads-up so they can check your INR a little more closely at first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Melchior RW, Dreher M, Ramsey E, Savoca M, Rosenthal T. Cardiopulmonary bypass considerations for pediatric patients on the ketogenic diet. Perfusion. 2015;30(5):423-6. PubMed
  2. Dressler A, Chiara H, Benninger F, et al. Effects of the ketogenic diet on platelet counts and global coagulation tests in childhood epilepsy. Seizure. 2020;80:31-37. 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

Ketogenic Diet Also Interacts With Other Medications

Ketogenic Diet has 137 moderate, 121 minor known drug interactions in our database — the Warfarin Sodium one above is one of them. If you take anything else, check it against the full list below.

Moderate 137 Minor 121 No known interaction 2,572 (incl. Warfarin Sodium)
Taking anything else?

Check Another of Your Medications Against Ketogenic Diet

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

From our Q&A

Questions About Ketogenic Diet 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 Ketogenic Diet 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 Ketogenic Diet 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

How much people look this up

Where Ketogenic Diet 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 Ketogenic Diet
Steady interest

#1,206 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Warfarin Sodium
Top 1%

#18 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.

Eating pattern

About Ketogenic Diet

What is Ketogenic Diet?

  • Weight loss
  • Type 2 diabetes and blood sugar control
  • Drug-resistant epilepsy (especially in children)
  • Reducing appetite
  • Athletic and metabolic interest

The ketogenic diet is a very low-carbohydrate, high-fat eating plan that shifts the body to burn fat for fuel. It has the strongest evidence as a medical therapy for hard-to-treat epilepsy and may help short-term weight loss and blood sugar, but it can be hard to sustain and is not right for everyone. Talk with a doctor or pharmacist before starting, especially if you have a medical condition or take medication.

Read the full Ketogenic Diet 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 & Ketogenic Diet

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

0Major
137Moderate
121Minor
2,571No known interaction
137 Moderate 121 Minor 2,571 No interaction
Moderate

137 interactions

Showing 60 of 137 moderate interactions — see all 137 on the Ketogenic Diet page.

Minor

121 interactions

Showing 60 of 121 minor interactions — see all 121 on the Ketogenic Diet page.

No interaction 2,571 drugs checked — show the list

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

Showing the 60 most looked-up of 2,571 medications checked with no known interaction — see the full Ketogenic Diet list.

See the full Ketogenic Diet 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
Ketogenic Diet 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

Following Ketogenic Diet While Taking Warfarin Sodium: Common Questions

Can you follow Ketogenic Diet while taking Warfarin Sodium?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Ketogenic Diet and Warfarin Sodium interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Warfarin Sodium and Ketogenic Diet?

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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.