The short answer
Possibly. A French pharmacovigilance report describes a probable interaction in which a person taking turmeric alongside fluindione, a blood thinner of the same family as warfarin, developed a raised INR. A raised INR means blood takes longer to clot, which raises the risk of bleeding.
A lab study found that curcumin, the main active compound in turmeric, can change the liver enzymes that handle warfarin. No trial has tested the pair in people. This page is about turmeric taken as a remedy or supplement. If you take warfarin or acenocoumarol, tell your prescribing doctor before starting turmeric or curcumin capsules, and ask whether your INR should be checked more often.
At a glance
| What was seen | How it may work | Direction | Evidence |
|---|---|---|---|
| Raised INR[1] | Not established | Increased blood-thinning effect | Case report |
| Curcumin altered CYP1A2 and CYP3A in liver cells[2] | Enzyme inhibition in pig liver cells and microsomes | Could change warfarin levels | In vitro |
No listing is not a clearance. A missing interaction here never means a combination is safe.
The evidence, study by study
Case report, France, 2014 Case report
Regional pharmacovigilance centres in Bordeaux and Grenoble report a probable interaction between fluindione, an oral vitamin K antagonist, and turmeric, resulting in a raised INR. The authors stress asking about herbal medicines whenever a patient on these drugs has an unexplained change.[1]
Laboratory study, 2022 In vitro
In pig liver cells, curcumin reduced the activity of CYP1A2 and CYP3A, two of the enzymes that break down warfarin, both alone and when given with warfarin. Lab findings like this show a possible route for an interaction. They do not show that one happens in people.[2]
What to tell your prescribing doctor
You can read this out, or show them this page:
“I am taking, or planning to take, turmeric or curcumin (name of product, dose) along with my blood thinner. There is a reported case of a raised INR with this combination. Should my INR be checked more often?”
Withheld until review
Related
Sources
- Daveluy A, Géniaux H, Thibaud L, et al. Probable interaction between an oral vitamin K antagonist and turmeric (Curcuma longa). Therapie. 2014;69(6):519-20. PMID 25230280.
- Burkina V, Zamaratskaia G, Rasmussen MK. Curcumin and quercetin modify warfarin-induced regulation of porcine CYP1A2 and CYP3A expression and activity in vitro. Xenobiotica. 2022;52(5):435-441. PMID 35695287.
Awaiting review by The Good Vaidya Medical Board. Prepared from the sources below and checked against each one.
Published 4 November 2026 · Last updated 4 November 2026
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