Chondroitin Sulfate + Warfarin
Warfarin brand name: Warfarin.
Chondroitin Sulfate has a moderate interaction with Warfarin. Taking chondroitin in combination with glucosamine might increase the anticoagulant effects of warfarin.
Read the full interaction reportChondroitin Sulfate and Warfarin
Here is the interaction we found between these two, with the evidence behind it.
WARFARIN (Coumadin)
There have been multiple reports of increased international normalized ratio (INR) in patients taking warfarin with glucosamine, with or without chondroitin. The lack of reports with chondroitin alone seem to suggest that the interactions occurring in these reports may have been due to glucosamine. In two individual case reports, glucosamine/chondroitin combinations were associated with a significant increase in INR in patients previously stabilized on warfarin. Additionally, 20 voluntary case reports to the US 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, without chondroitin, to increased INR in patients taking warfarin.
Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..
Here's the honest picture with warfarin and chondroitin. Warfarin is a tricky blood thinner with a narrow safety window, so even small shifts can nudge your INR (the lab number that tracks how thin your blood is) too high. The concern on file is that chondroitin, usually taken alongside glucosamine, might boost warfarin's effect a bit, which could mean more bruising, nosebleeds, or bleeding that's slow to stop.
That said, this is built on scattered case reports, and most of those folks were taking glucosamine too. Chondroitin on its own hasn't clearly been pinned as the culprit, so I'd call this possible but unlikely. Still, since it's warfarin, please loop in your pharmacist or doctor before starting, so they can keep an eye on your INR.
- Rozenfeld V, Crain JL, Callahan AK. Possible augmentation of warfarin effect by glucosamine-chondroitin. Am J Health Syst Pharm 2004;61:306-307. PubMed
- 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
- 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.
Clinically significant. Avoid the combination, or use only under close professional supervision.
Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.
Generally not serious. Be aware of it and mention it to your pharmacist.
- 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.
- 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.
Chondroitin Sulfate Also Interacts With Other Medications
Chondroitin Sulfate has 1 moderate known drug interaction in our database — the Warfarin one above is one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Chondroitin Sulfate
We haven’t checked that one against Chondroitin Sulfate yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Chondroitin Sulfate. Pick one to open its full report.
Questions About Chondroitin Sulfate or Warfarin
These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Chondroitin Sulfate or Warfarin, 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:
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Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.
See Every Supplement That Interacts With Warfarin
This page covers Chondroitin Sulfate only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Warfarin 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).
By severity: 16 major · 301 moderate · 44 minor.
From our pharmacist’s overview on the Warfarin page
“People take warfarin to prevent dangerous clots, and many are the same people reaching for glucosamine for sore joints or a multivitamin containing vitamin K, which makes this a list that deserves genuine respect. Of the 361 supplements on file for warfarin, 16 carry a major rating, and the danger runs in both directions: some add to w…”
Reviewed by 2 · Jul 18, 2026
Taking Chondroitin Sulfate as Part of a Dietary Supplement Product? Check It for Interactions
We hold 2,347 real supplement products containing Chondroitin Sulfate, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chondroitin Sulfate. Your product may carry other ingredients that interact with Warfarin too, on top of Chondroitin Sulfate — and those would not show on this page. Find your product and we’ll check every ingredient on its label:
Where Chondroitin Sulfate and Warfarin 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.
#115 of 1,452 supplements looked up here in the last 7 days
#4 of 2,830 medications looked up here in the last 7 days
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.
About Chondroitin Sulfate
What is Chondroitin Sulfate?
- Osteoarthritis joint pain
- Joint stiffness
- Cartilage support
- Dry eye (eye drops)
Chondroitin sulfate is a naturally occurring building block of cartilage that is widely taken, often with glucosamine, for osteoarthritis joint pain. The evidence is mixed—some people report modest relief while large studies show little or no benefit—but it appears generally well tolerated. Talk with your pharmacist or doctor before starting, especially if you have allergies or other health conditions.
About Warfarin
What Is Warfarin Used For?
Brand name: Warfarin
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.
Other Drugs & Chondroitin Sulfate
Browse every other medication we’ve checked against Chondroitin Sulfate — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
1 interaction
No interaction 2,828 drugs checked — show the list
We also checked Chondroitin Sulfate against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Sertraline ›
- Testosterone ›
- Losartan Potassium ›
- Metoprolol ›
- Aspirin ›
- Ivermectin ›
- Rivaroxaban ›
- Rosuvastatin ›
- Escitalopram ›
- Acetaminophen ›
- Tadalafil ›
- Clopidogrel ›
- Atorvastatin ›
- Docusate ›
- Hydroxyurea ›
- Abemaciclib ›
- Valacyclovir ›
- Methamphetamine ›
- Ibuprofen ›
- Semaglutide ›
- Sumatriptan ›
- Tirzepatide ›
- Prednisone ›
- Propranolol ›
- Bupropion ›
- Lisdexamfetamine ›
- Metformin ›
- Amoxicillin ›
- Lisinopril ›
- Acyclovir ›
- Bendamustine ›
- Amitriptyline ›
- Doxycycline ›
- Methotrexate ›
- Lamotrigine ›
- Fluoxetine ›
- Acetaminophen, Codeine ›
- Amphetamine ›
- Gabapentin ›
- Pregabalin ›
- Dextroamphetamine ›
- Azithromycin ›
- Isotretinoin ›
- Clonazepam ›
- Omeprazole ›
- Methylene Blue ›
- Quetiapine ›
- Amlodipine Besylate ›
- Duloxetine ›
- Letrozole ›
- Buspirone ›
- Citalopram ›
- Naproxen ›
- Ciprofloxacin ›
- Bisoprolol ›
- Levothyroxine, Liothyronine ›
Showing the 60 most looked-up of 2,828 medications checked with no known interaction — see the full Chondroitin Sulfate list.
Sources & How We Checked
Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference for vitamins, herbs and supplements — the basis for our interaction data.
- MedlinePlus, U.S. National Library of Medicine — NIH consumer drug information, used for the medication overviews.
- NIH Dietary Supplement Label Database (DSLD) — Official supplement product labels.
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
Taking Chondroitin Sulfate and Warfarin Together: Common Questions
Can you take Chondroitin Sulfate with Warfarin?
How serious is the Chondroitin Sulfate and Warfarin interaction?
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