Drug & supplement interaction

Safflower + Acenocoumarol

Acenocoumarol brand name: Sintrom.

Moderate Interaction
The bottom line Moderate

Safflower has a moderate interaction with Acenocoumarol. High doses of safflower oil might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.

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

Safflower and Acenocoumarol

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Acenocoumarol

Acenocoumarol falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Safflower interacts with.

High doses of safflower oil might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
Small clinical studies show that taking safflower oil, approximately 55 grams daily for 2-3 weeks, decreases platelet aggregation. However, taking lower doses of safflower oil, such as 5 grams daily for 4 weeks, does not seem to affect platelet function. In one case report, a 74-year-old male stabilized on warfarin developed urinary tract bleeding and an elevated INR after taking a safflower extract 20 grams daily for 14 days.
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

Acenocoumarol (Sintrom) is a blood thinner that works by lowering your body's clotting ability, and doctors track it closely with INR blood tests. The concern here is simple: large, concentrated doses of safflower (think roughly 20 grams or more of safflower oil or extract daily) may make your blood slightly less likely to clot on its own. Stacked on top of Sintrom, that could nudge your INR higher and raise the chance of bleeding, such as easy bruising, nosebleeds, bleeding gums, or blood in your urine. A real case report showed exactly that pattern.

The reassuring part: small amounts of safflower oil used in cooking are very unlikely to cause trouble. It's the heavy supplement doses that matter. Please don't change anything on your own. Just check with your pharmacist or doctor before starting a safflower supplement so your INR can be watched.

References
  1. Demke, D. M., Peters, G. R., Linet, O. I., Metzler, C. M., and Klott, K. A. Effects of a fish oil concentrate in patients with hypercholesterolemia. Atherosclerosis 1988;70(1-2):73-80. PubMed
  2. Kwon, J. S., Snook, J. T., Wardlaw, G. M., and Hwang, D. H. Effects of diets high in saturated fatty acids, canola oil, or safflower oil on platelet function, thromboxane B2 formation, and fatty acid composition of platelet phospholipids. Am.J.Clin.Nutr. PubMed
  3. Challen, A. D., Branch, W. J., and Cummings, J. H. The effect of aspirin and linoleic acid on platelet aggregation, platelet fatty acid composition and haemostasis in man. Hum Nutr Clin Nutr 1983;37(3):197-208.
  4. Liu Y, Liu S, Shi Y, et al. Effects of safflower injection on the pharmacodynamics and pharmacokinetics of warfarin in rats. Xenobiotica. 2017 Oct 25:1-6. [Epub ahead of print] 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

Safflower Also Interacts With Other Medications

Safflower has 207 moderate known drug interactions in our database — the Acenocoumarol one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Safflower

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

Everything else you take

See Every Supplement That Interacts With Acenocoumarol

This page covers Safflower only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Acenocoumarol page lists 221 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Danshen (major), Piracetam (major), Acetyl-l-carnitine (moderate) and Aconite (moderate).

By severity: 3 major · 193 moderate · 25 minor.

From our pharmacist’s overview on the Acenocoumarol page

“Acenocoumarol (Sintrom) is a blood thinner in the warfarin family, and it lives in a narrow zone where a little too much means bleeding and a little too little means clots. So treat its 221 supplement interactions as a real safety issue, not fine print.”

Reviewed by 2 · Jul 18, 2026

Open the Acenocoumarol interaction page

One more smart check

Taking Safflower as Part of a Dietary Supplement Product? Check It for Interactions

We hold 276 real supplement products containing Safflower, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Safflower. Your product may carry other ingredients that interact with Acenocoumarol too, on top of Safflower — 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 Safflower and Acenocoumarol 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 Safflower
Top half

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

29 days ago today
Medication Acenocoumarol
Top 25%

#431 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 Safflower

What is Safflower?

Safflower
  • Heart and cholesterol support
  • Skin moisturizing
  • Menstrual cramps
  • Mild constipation
  • Weight management (oil)

Safflower is a thistle-like plant used mainly for its seed oil (a common cooking oil) and its colorful flowers. Safflower oil is a reasonable source of unsaturated fats, but strong proof that supplements treat specific diseases is limited. The flower extracts have much weaker evidence and should be used with caution, especially during pregnancy.

Read the full Safflower monograph & all interactions
Keep checking

Other Drugs & Safflower

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

0Major
207Moderate
0Minor
2,622No known interaction
Moderate

207 interactions

Showing 60 of 207 moderate interactions — see all 207 on the Safflower page.

No interaction 2,622 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Safflower and Acenocoumarol Together: Common Questions

Can you take Safflower with Acenocoumarol?
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.
How serious is the Safflower and Acenocoumarol 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

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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.