Flaxseed - Coumadin (Warfarin Sodium) Interaction
Herbal: Flaxseed
Also Known As: Linum usitatissimum, Alasi, Aliviraaii, Brown Flaxseed, Brown-Seeded Flax, Common Flax, Echter Lein, Flachs, Flachssamen, Flax, Flax Hull, Flax Lignans, Flax Meal, Flax Seed, Gemeiner Flachs, Golden Flax, Graine de Lin, Kattan, Keten, Leinsamen, Lignanes de Lin, Lignans, Lin
Drug: Warfarin Sodium
Brand names:
Coumadin, Panwarfin, Sofarin
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Apr 20, 2025
Interaction Details
Warfarin Sodium is classified as belonging to the following category: Anticoagulant/Antiplatelet Drugs
Theoretically, using flaxseed in combination with anticoagulant or antiplatelet drugs might have additive effects and increase the risk of bleeding.
Some clinical evidence suggests that the oil contained in flaxseed can decrease platelet aggregation.
Interaction Rating
Likelihood of Occurrence
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
Pharmacist Analysis
Some evidence suggests that flaxseed may have mild blood-thinning effects, but this is mainly observed in diabetic patients.
Most studies in healthy individuals have not found significant changes in blood clotting after taking flaxseed oil supplements for one to three months.
One study compared the effects of flaxseed oil and fish oil in healthy individuals and found no significant differences in bleeding time or other clotting factors between the two groups.
Overall, while there is a theoretical interaction between flaxseed and warfarin based on a combined anticoagulant effect, the risk is low it is clinically significant.
Regardless, it is always important to be aware of signs of easy bruising and bleeding while taking an anticoagulant like warfarin.
- Dr. Brian Staiger, PharmDReferences
- Nordstrom DC, Honkanen VE, Nasu Y, et al. Alpha-linolenic acid in the treatment of rheumatoid arthritis. A double-blind, placebo-controlled and randomized study: flaxseed vs. safflower seed. Rheumatol Int 1995;14:231-4.
- Allman, M. A., Pena, M. M., and Pang, D. Supplementation with flaxseed oil versus sunflowerseed oil in healthy young men consuming a low fat diet: effects on platelet composition and function. Eur.J Clin.Nutr. 1995;49(3):169-178.
Flaxseed Overview
Flaxseed, also known as linseed, is a type of seed that is rich in nutrients and other compounds. It is a good source of fiber, protein, and omega-3 fatty acids, as well as a variety of vitamins and minerals. Flaxseed is often ground and used as a supplement in the form of flaxseed meal or oil.
Flaxseed has a number of potential health benefits. It is high in fiber, which can help improve digestion and lower cholesterol levels. The omega-3 fatty acids found in flaxseed are believed to have anti-inflammatory properties and may help reduce the risk of heart disease and stroke. Flaxseed is also a rich source of lignans, plant compounds that have been shown to have estrogen-like effects.
Both flaxseed and flaxseed oil are popular dietary supplements and share many of the same purported health benefits. However, one of the main differences between the two is the amount of fiber they contain. Flaxseed is a good source of both soluble and insoluble fiber, while flaxseed oil does not contain any fiber. This means that flaxseed can help improve digestion and lower cholesterol levels, while flaxseed oil does not have these effects.
Warfarin Sodium Overview
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Warfarin is used to prevent blood clots from forming or growing larger in your blood and blood vessels. It is prescribed for people with certain types of irregular heartbeat, people with prosthetic (replacement or mechanical) heart valves, and people who have suffered a heart attack. Warfarin is also used to treat or prevent venous thrombosis (swelling and blood clot in a vein) and pulmonary embolism (a blood clot in the lung). Warfarin is in a class of medications called anticoagulants ('blood thinners'). It works by decreasing the clotting ability of the blood.
Flaxseed - More Interactions
Flaxseed interacts with 588 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
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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
Drug descriptions are provided by MedlinePlus.
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Dr. Brian Staiger, PharmD
In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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