Drug & supplement interaction

Turmeric + Warfarin Sodium

Warfarin Sodium brand names: Coumadin, Panwarfin, Sofarin.

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

Warfarin Sodium falls into 4 drug categories that Turmeric can interact with; the most serious is rated moderate. Turmeric might increase or decrease levels of drugs metabolized by CYP3A4.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions4
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Turmeric and Warfarin Sodium

These two interact in 4 distinct ways. Each one is explained separately below.

Why Are There 4 Interactions?

Turmeric interacts with whole categories of medication. Warfarin Sodium falls into 4 of those categories, so it can interact with Turmeric in 4 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

1 of 4

Why this applies to Warfarin Sodium

Warfarin Sodium falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Turmeric interacts with.

Turmeric might increase or decrease levels of drugs metabolized by CYP3A4.
In vitro and animal research show that turmeric and its constituents curcumin and curcuminoids inhibit CYP3A4. Also, 8 case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking turmeric and cancer medications that are CYP3A4 substrates, including everolimus, ruxolitinib, ibrutinib, and palbociclib, and bortezomib. In another case report, a transplant patient presented with acute nephrotoxicity and elevated tacrolimus levels after consuming turmeric powder at a dose of 15 or more spoonfuls daily for ten days prior. It was thought that turmeric increased levels of tacrolimus due to CYP3A4 inhibition.
Conversely, other in vitro research suggests that turmeric induces CYP3A4 activity, leading to reduced levels of CYP3A4 substrates. An animal model suggests that induction of CYP3A4 occurs after daily curcumin use for 1 week. However, the induction of CYP3A4 by turmeric 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 deal with turmeric and your warfarin. Warfarin is partly cleared by a liver enzyme called CYP3A4, and lab and animal studies suggest the curcumin in turmeric can affect that enzyme, mostly slowing it down. If it slows your warfarin's breakdown, more warfarin can hang around, which could nudge your INR up and raise your risk of bruising, nosebleeds, or other bleeding. Some research hints turmeric could speed the enzyme up instead, which would push the other way.

I want to be honest: this is weak, mostly test-tube evidence, not strong human data. But warfarin is a finicky drug where small shifts matter. The pinch you use in cooking is unlikely to be a problem; concentrated supplements are the concern. Please check with your pharmacist or doctor before adding one.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Appiah-Opong, R., Commandeur, J. N., Vugt-Lussenburg, B., and Vermeulen, N. P. Inhibition of human recombinant cytochrome P450s by curcumin and curcumin decomposition products. Toxicology 6-3-2007;235(1-2):83-91. PubMed
  2. Hou, X. L., Takahashi, K., Kinoshita, N., Qiu, F., Tanaka, K., Komatsu, K., Takahashi, K., and Azuma, J. Possible inhibitory mechanism of Curcuma drugs on CYP3A4 in 1alpha,25 dihydroxyvitamin D3 treated Caco-2 cells. Int.J Pharm 6-7-2007;337(1-2):169-177.
  3. Valentine, S. P., Le Nedelec, M. J., Menzies, A. R., Scandlyn, M. J., Goodin, M. G., and Rosengren, R. J. Curcumin modulates drug metabolizing enzymes in the female Swiss Webster mouse. Life Sci. 4-11-2006;78(20):2391-2398. PubMed
  4. Nayeri A, Wu S, Adams E, et al. Acute Calcineurin Inhibitor Nephrotoxicity Secondary to Turmeric Intake: A Case Report. Transplant Proc. 2017;49(1):198-200. PubMed
  5. Haron MH, Dale O, Martin K, et al. Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2. J Diet Suppl 2022. PubMed
  6. Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178. PubMed
  7. Dibaei M, Hosseini A, Lavasani H, Kiani-Dehkordi B, Rouini M. Assessment of metabolic interaction between curcumin and tramadol using the isolated perfused rat liver. Heliyon 2024;10(15):e35070. PubMed
Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 4

Warfarin Sodium also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Turmeric may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs. However, research is conflicting.
Curcumin, a constituent of turmeric, has demonstrated antiplatelet effects in vitro. Furthermore, two case reports have found that taking turmeric along with warfarin or fluindione was associated with an increased international normalized ratio (INR). However, one clinical study in healthy volunteers shows that taking curcumin 500 mg daily for 3 weeks, alone or with aspirin 100 mg, does not increase antiplatelet effects or bleeding risk. It is possible that the dose of turmeric used in this study was too low to produce a notable effect.
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's the thing to keep in mind: warfarin is already a powerful blood thinner with a very narrow safe zone, which is why your doctor checks your INR regularly. Turmeric's curcumin may have a mild blood-thinning (antiplatelet) effect of its own, so taking concentrated turmeric supplements alongside warfarin could nudge your bleeding risk a little higher. We've seen a couple of case reports where the INR climbed, but a small clinical study didn't find much change, so the evidence is genuinely mixed.

What this could look like in real life is easy bruising, nosebleeds, bleeding gums, or blood in the urine or stool. The pinch of turmeric in your curry is very unlikely to matter. Concentrated capsules are the concern. Please don't start or stop anything on your own, just check with your pharmacist or doctor first so your INR can be watched.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Shah BH, Nawaz Z, Pertani SA. Inhibitory effect of curcumin, a food spice from turmeric, on platelet-activating factor- and arachidonic acid-mediated platelet aggregation through inhibition of thromboxane formation and Ca2+ signaling. Biochem Pharmacol 1 PubMed
  2. Srivastava, R., Puri, V., Srimal, R. C., and Dhawan, B. N. Effect of curcumin on platelet aggregation and vascular prostacyclin synthesis. Arzneimittelforschung. 1986;36(4):715-717.
  3. Srivastava, K. C., Bordia, A., and Verma, S. K. Curcumin, a major component of food spice turmeric (Curcuma longa) inhibits aggregation and alters eicosanoid metabolism in human blood platelets. Prostaglandins Leukot.Essent.Fatty Acids 1995;52(4):223-227 PubMed
  4. Daveluy A, Géniaux H, Thibaud L, Mallaret M, Miremont-Salamé G, Haramburu F. Probable interaction between an oral vitamin K antagonist and turmeric (Curcuma longa). Therapie. 2014 Nov-Dec;69(6):519-20. PubMed
  5. Fung FY, Wong WH, Ang SK, et al. A randomized, double-blind, placebo- controlled study on the anti-haemostatic effects of Curcuma longa, Angelica sinensis and Panax ginseng. Phytomedicine. 2017;32:88-96. PubMed
  6. Medsafe Safety Communication- Turmeric/Curcumin Interaction with Warfarin. April 30, 2018. Accessed at: https://medsafe.govt.nz/safety/EWS/2018/Turmeric.asp.
Moderate

WARFARIN (Coumadin)

3 of 4
Turmeric might increase the risk of bleeding with warfarin.
One case of increased international normalized ratio (INR) has been reported for a patient taking warfarin who began taking turmeric. Prior to taking turmeric, the patient had stable INR measurements. Within a few weeks of starting turmeric supplementation, the patient's INR increased to 10. Additionally, curcumin, the active constituent in turmeric, has demonstrated antiplatelet effects in vitro, which may produce additive effects when taken with warfarin.
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 deal with turmeric and warfarin. Warfarin is one of those medications where the dose is dialed in very precisely, and your blood level is tracked with a number called the INR. Turmeric (really its active compound, curcumin) can nudge your blood toward thinning a little more, partly by affecting how your platelets stick together. Layered on top of warfarin, that may add up to too much blood thinning.

Honestly, the evidence here is thin, basically a single reported case where someone's INR jumped sky-high after adding turmeric, plus some lab data. Sprinkling turmeric on your food is very unlikely to matter. Concentrated capsules are the bigger question. Watch for easy bruising, nosebleeds, or unusual bleeding, and please check with your pharmacist or doctor before starting a supplement.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Shah BH, Nawaz Z, Pertani SA. Inhibitory effect of curcumin, a food spice from turmeric, on platelet-activating factor- and arachidonic acid-mediated platelet aggregation through inhibition of thromboxane formation and Ca2+ signaling. Biochem Pharmacol 1 PubMed
  2. Srivastava, R., Puri, V., Srimal, R. C., and Dhawan, B. N. Effect of curcumin on platelet aggregation and vascular prostacyclin synthesis. Arzneimittelforschung. 1986;36(4):715-717.
  3. Srivastava, K. C., Bordia, A., and Verma, S. K. Curcumin, a major component of food spice turmeric (Curcuma longa) inhibits aggregation and alters eicosanoid metabolism in human blood platelets. Prostaglandins Leukot.Essent.Fatty Acids 1995;52(4):223-227 PubMed
  4. Medsafe Safety Communication- Turmeric/Curcumin Interaction with Warfarin. April 30, 2018. Accessed at: https://medsafe.govt.nz/safety/EWS/2018/Turmeric.asp.
Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

4 of 4

Warfarin Sodium also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, turmeric might increase levels of drugs metabolized by CYP1A2. However, research is conflicting.
In vitro and animal research show that the turmeric constituent, curcumin, inhibits CYP1A2. However, other in vitro research suggests that curcumin does not significantly affect CYP1A2.
Severity Minor 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 warfarin and turmeric. The theory is that curcumin, the active part of turmeric, might slow down a liver enzyme called CYP1A2 that helps clear warfarin. If that happened, warfarin could build up a little and thin your blood more than intended, which raises the chance of bruising, nosebleeds, or harder to stop bleeding. But honestly, this concern rests on lab and animal data only, and even those studies disagree with each other.

Warfarin is a narrow therapeutic index drug, meaning small shifts can move your INR, so I don't take any potential interaction lightly. Cooking with turmeric as a spice is very unlikely to matter. A concentrated supplement is a different story. Please check with your pharmacist or doctor before starting one, and don't change anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Thapliyal R, Deshpande SS, Maru GB. Mechanism(s) of turmeric-mediated protective effects against benzo(a)pyrene-derived DNA adducts. Cancer Lett 2002;175:79-88. PubMed
  2. Appiah-Opong, R., Commandeur, J. N., Vugt-Lussenburg, B., and Vermeulen, N. P. Inhibition of human recombinant cytochrome P450s by curcumin and curcumin decomposition products. Toxicology 6-3-2007;235(1-2):83-91. PubMed
  3. Price, R. J., Scott, M. P., Giddings, A. M., Walters, D. G., Stierum, R. H., Meredith, C., and Lake, B. G. Effect of butylated hydroxytoluene, curcumin, propyl gallate and thiabendazole on cytochrome P450 forms in cultured human hepatocytes. Xenobiotica 2 PubMed
  4. Oetari, S., Sudibyo, M., Commandeur, J. N., Samhoedi, R., and Vermeulen, N. P. Effects of curcumin on cytochrome P450 and glutathione S-transferase activities in rat liver. Biochem Pharmacol 1-12-1996;51(1):39-45. 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

Turmeric Also Interacts With Other Medications

Turmeric has 1,055 moderate, 77 minor known drug interactions in our database — the Warfarin Sodium one above is among them. If you take anything else, check it against the full list below.

Moderate 1,055 Minor 77 No known interaction 1,698 (incl. Warfarin Sodium)
Taking anything else?

Check Another of Your Medications Against Turmeric

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

From our Q&A

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

We hold 1,368 real supplement products containing Turmeric, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Turmeric. Your product may carry other ingredients that interact with Warfarin Sodium too, on top of Turmeric — 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 Turmeric 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 Turmeric
Top 5%

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

29 days ago today
Medication Warfarin Sodium
Top 1%

#26 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 Turmeric

What is Turmeric?

Turmeric
  • Joint pain and arthritis
  • Inflammation
  • Digestive upset
  • Antioxidant support
  • Skin conditions

Turmeric is a popular spice whose main active compounds, curcuminoids, are studied mostly for inflammation and joint pain. Some research is promising, but quality is mixed and curcumin is poorly absorbed on its own. For most people, dietary amounts are safe, but talk to your pharmacist or doctor before taking concentrated supplements, especially if you are pregnant, nursing, or have a medical condition.

Read the full Turmeric 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 & Turmeric

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

0Major
1,055Moderate
77Minor
1,697No known interaction
1,055 Moderate 77 Minor 1,697 No interaction
Moderate

1,055 interactions

Showing 60 of 1,055 moderate interactions — see all 1,055 on the Turmeric page.

Minor

77 interactions

Showing 60 of 77 minor interactions — see all 77 on the Turmeric page.

No interaction 1,697 drugs checked — show the list

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

Showing the 60 most looked-up of 1,697 medications checked with no known interaction — see the full Turmeric list.

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

Can you take Turmeric with Warfarin Sodium?
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 4 interactions listed for Turmeric and Warfarin Sodium?
Warfarin Sodium belongs to more than one drug category, and Turmeric 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 Turmeric and Warfarin Sodium 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 Warfarin Sodium and Turmeric?

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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.