Drug & supplement interaction

Glucosamine + Warfarin Sodium

Warfarin Sodium brand names: Coumadin, Panwarfin, Sofarin.

Major Interaction
Medically reviewed by · Updated October 2026
The bottom line Major

Glucosamine has a major interaction with Warfarin Sodium. Glucosamine might increase the anticoagulant effects of warfarin and increase the risk of bruising and bleeding.

Read the full interaction report
SeverityMajor
LikelihoodProbable
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Glucosamine and Warfarin Sodium

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

Major

WARFARIN (Coumadin)

Glucosamine might increase the anticoagulant effects of warfarin and increase the risk of bruising and bleeding.
In two individual case reports, glucosamine/chondroitin combinations were associated with a significant increase in international normalized ratio (INR) in patients previously stabilized on warfarin. In one case, the increase in INR occurred only after tripling the dose of a glucosamine/chondroitin supplement from 500 mg/400 mg daily to 1500/1200 mg daily. Additionally, 20 voluntary case reports to the U.S. Food & Drug Administration (FDA) have linked glucosamine plus chondroitin with increased INR, bruising, and bleeding in patients who were also taking warfarin. There have also been 20 additional case reports to the World Health Organization (WHO) that link glucosamine alone to increased INR in patients taking warfarin. The mechanism of this interaction is unclear. Glucosamine is a small component of heparin, but is not thought to have anticoagulant activity; however, animal research suggests that it might have antiplatelet activity.
Severity Major Likelihood Probable Evidence D

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..

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

Here's the practical concern with pairing glucosamine and warfarin. Warfarin keeps your blood from clotting too easily, and its dosing is carefully balanced using your INR blood test. The worry is that glucosamine may push your INR higher, which means your blood gets thinner than intended. That can show up as easy bruising, nosebleeds, bleeding gums, blood in your urine or stool, or cuts that won't stop bleeding.

I want to be honest about the evidence here. This is based on scattered case reports, not strong studies, and the exact reason it happens isn't clear. But because warfarin is a drug where even small shifts matter, I'd take it seriously. Please don't start or stop anything on your own. Talk with your pharmacist or doctor first, and if you do add glucosamine, your INR should be checked more closely.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Rozenfeld V, Crain JL, Callahan AK. Possible augmentation of warfarin effect by glucosamine-chondroitin. Am J Health Syst Pharm 2004;61:306-307. PubMed
  2. Knudsen J, Sokol GH. Potential glucosamine-warfarin interaction resulting in increased international normalized ratio: Case report and review of the literature and MedWatch database. Pharmacotherapy 2008;28:540-8. PubMed
  3. Yue QY, Strandell J, Myrberg O. Concomitant use of glucosamine potentiates the effect of warfarin. Jan 2006. Drug Safety 29(10):911-1010. DOI

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

Glucosamine Also Interacts With Other Medications

Glucosamine has 1 major, 13 moderate, 155 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.

Major 1 Moderate 13 Minor 155 No known interaction 2,661 (incl. Warfarin Sodium)
Taking anything else?

Check Another of Your Medications Against Glucosamine

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

From our Q&A

Questions About Glucosamine 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 Glucosamine 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 Glucosamine 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 Glucosamine as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,984 real supplement products containing Glucosamine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Glucosamine. Your product may carry other ingredients that interact with Warfarin Sodium too, on top of Glucosamine — 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 Glucosamine 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 Glucosamine
Top 10%

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

29 days ago today
Medication Warfarin Sodium
Top 5%

#30 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 Glucosamine

What is Glucosamine?

Glucosamine
  • Osteoarthritis
  • Joint pain and stiffness
  • Cartilage support
  • Knee and hip joint health

Glucosamine is a natural compound found in cartilage and joint fluid, and it is one of the most popular supplements for osteoarthritis, especially of the knee. The evidence is mixed, with some people getting modest relief while others get little to no benefit. It is generally well tolerated, but talk to your pharmacist or doctor before starting it, especially if you have a shellfish allergy or diabetes.

Read the full Glucosamine monograph & all interactions
Medication

About Warfarin

What Is Warfarin Used For?

Brand names: Coumadin, Panwarfin, Sofarin

Warfarin helps prevent and treat harmful blood clots. The label lists these uses for both Warfarin Sodium tablets and Jantoven tablets:

  • Preventing and treating venous thrombosis (clots in the veins) and pulmonary embolism (clots in the lungs).
  • Preventing and treating clot-related complications of atrial fibrillation and/or heart valve replacement.
  • Lowering the risk of death, another heart attack, and clot-related events such as stroke after a heart attack.

Warfarin does not dissolve a clot that has already formed. It helps stop the clot from growing and prevents further clot-related complications.

See full Warfarin drug information
Keep checking

Other Drugs & Glucosamine

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

1Major
13Moderate
155Minor
2,660No known interaction
1 Major 13 Moderate 155 Minor 2,660 No interaction
Major

1 interaction

Moderate

13 interactions

Minor

155 interactions

Showing 60 of 155 minor interactions — see all 155 on the Glucosamine page.

No interaction 2,660 drugs checked — show the list

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

Showing the 60 most looked-up of 2,660 medications checked with no known interaction — see the full Glucosamine list.

See the full Glucosamine 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
Glucosamine 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 Glucosamine and Warfarin Sodium Together: Common Questions

Can you take Glucosamine with Warfarin Sodium?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Glucosamine and Warfarin Sodium interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Warfarin Sodium and Glucosamine?

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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.