The short answer
Yes, there are reports of an interaction. New Zealand's medicines regulator describes a person whose INR had been stable on warfarin and rose above 10 within a few weeks of starting turmeric. A French report describes a probable interaction in which turmeric raised the INR of a person on fluindione, a blood thinner of the same family as warfarin. A raised INR means blood takes longer to clot, which raises the risk of bleeding.
These reports are about turmeric taken as a remedy or supplement. Haldi in food is a different exposure, and it has not been tested. 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.
Warfarin is sold in India as Warf and acenocoumarol as Acitrom. Low-dose aspirin is sold as Ecosprin.
At a glance
| What was seen | How it may work | Direction | Evidence |
|---|---|---|---|
| INR above 10 in a person stable on warfarin[1] | Not established | Increased blood-thinning effect | Case report |
| Raised INR in a person on fluindione[2] | Not established | Increased blood-thinning effect | Case report |
| Curcumin slowed CYP1A2 and CYP3A in pig liver cells[3] | Enzyme inhibition in pig liver cells and microsomes | Could change warfarin levels | In vitro |
| Possible longer bleeding time with other medicines that affect bleeding[1] | Proposed; not measured | More risk of bleeding | Theoretical by mechanism |
No listing is not a clearance. A missing interaction here never means a combination is safe.
The evidence, study by study
Regulator report, New Zealand, 2018 Case report
Medsafe received a report of a person whose INR had been stable on warfarin and rose to over 10 within a few weeks of starting turmeric. The notice does not say which product was used or how much. It is a single spontaneous report, and the notice concerns turmeric and curcumin products, not turmeric used in food. Medsafe adds that these products may prolong bleeding time with other medicines that affect bleeding.[1]
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. Fluindione is not warfarin, but it works in the same way. The authors stress asking about herbal medicines whenever a patient has an unexplained side effect.[2]
Laboratory study, 2022 In vitro
In pig liver cells exposed to warfarin, curcumin reduced the activity of CYP1A2 and CYP3A, two of the enzymes that break warfarin down. S-warfarin, one of warfarin's two forms, is cleared mainly by a different enzyme, CYP2C9, which this study did not test. Lab findings like this show a possible route for an interaction. They do not show that one happens in people.[3]
What your doctor may watch for
- Your INR. Warfarin has a narrow therapeutic range, and the New Zealand case showed a large rise within weeks.[4]
- Unusual bruising or bleeding, whichever blood thinner you take.[1]
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 are reported cases of a raised INR with this combination. Should my INR be checked more often?”
Withheld until review
Questions people ask
What about haldi in food, or turmeric tea?
Medsafe's notice is about turmeric and curcumin products, and we found no study of cooking amounts or turmeric tea with warfarin. That is not the same as showing they have no effect, so mention them to your doctor if you take them every day.[1]
Can I take turmeric with Ecosprin?
We found no study of turmeric with aspirin. Medsafe says turmeric products may prolong bleeding time when taken with medicines that affect bleeding, so tell your doctor if you take both.[1]
Related
Tulsi and blood thinners like warfarin
A man on warfarin had a high INR after a herbal kadha that included tulsi. Tulsi's own role is not clear, and it has not been studied alone.
InteractionGinger (adrak) and warfarin
Two women on blood thinners had a high INR after ginger supplements, and ginger users on warfarin reported more bleeding. One small study found no change.
InteractionTurmeric and painkillers like ibuprofen and diclofenac
No study has tested turmeric with NSAID painkillers. A regulator warns that turmeric supplements with these medicines may prolong bleeding.
InteractionGarlic and blood thinners (warfarin, aspirin, clopidogrel)
Health agencies warn garlic supplements may raise bleeding risk. Two small studies on warfarin found no effect, but they cannot rule out rarer bleeding.
Sources
- Medsafe (New Zealand Medicines and Medical Devices Safety Authority). Beware: turmeric/curcumin containing products can interact with warfarin. April 2018.
- 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;69(6):519-520. 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.
- Jantoven (warfarin sodium) tablets, US prescribing information (DailyMed).
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
Taking turmeric with other medicines? A vaidya can check your full list.
Medicine Check · ₹299