Alfalfa - Coumadin (Warfarin Sodium) Interaction
Herbal: Alfalfa
Also Known As: Medicago sativa, Feuille de Luzerne, Grand Trèfle, Herbe aux Bisons, Herbe à Vaches, Lucerne, Luzerne, Medicago, Phytoestrogen, Phyto-oestrogène, Purple Medick, Sanfoin
Drug: Warfarin Sodium
Brand names:
Coumadin, Panwarfin, Sofarin
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 25, 2025
Interaction Details
Warfarin Sodium is classified as belonging to the following category: Warfarin (Coumadin)
Theoretically, alfalfa might reduce the anticoagulant activity of warfarin.
Alfalfa contains a large amount of vitamin K. This could theoretically interfere with the activity of warfarin.
Interaction Rating
Likelihood of Occurrence
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.
References
- Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
- The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
Alfalfa Overview
Alfalfa, also known as Lucerne, is a perennial flowering plant in the pea family Fabaceae. It is native to southwestern Asia and the Mediterranean region, but it is now grown in many parts of the world, mainly as a forage crop for livestock. Alfalfa is a rich source of vitamins and minerals, such as vitamins A, C, E, and K, and manganese. It also contains coumestrol, a phytoestrogen. It has been used as a natural remedy for a variety of conditions, such as arthritis and high cholesterol. It may also help treat gastrointestinal disorders, rheumatoid arthritis (RA), asthma, menstrual irregularities, as well as bladder, kidney, and prostate issues.
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.
Alfalfa - More Interactions
Alfalfa interacts with 570 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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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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