Nattokinase With Xarelto Interaction
In our latest question and answer, our pharmacist discusses the interaction between Xarelto and Nattokinase.
Are there interactions between nattokinase and Xarelto?
Oct 14, 2025- Using nattokinase with Xarelto can increase your risk of bleeding because both thin the blood and may intensify each other's effects.
- Do not start nattokinase while taking Xarelto unless your doctor approves it first.
- Separating doses by time does not reduce this risk because the blood-thinning effects overlap for a long period.
Answer
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Does Nattokinase Interact with Xarelto?
Short answer: Yes. Using nattokinase with Xarelto (rivaroxaban) can increase the risk of bleeding. We classify this as moderate severity with a possible likelihood.
Why: Nattokinase has blood thinning and clot dissolving activity. Adding it to Xarelto can intensify overall anticoagulant effects, which may raise the chance of bruising, nosebleeds, gum bleeding, blood in urine or stool, or more serious bleeding.
Evidence snapshot: Published case experience has linked nattokinase used with other blood thinners or antiplatelets to serious bleeding events. Large high quality trials evaluating nattokinase together with prescription anticoagulants are lacking, so we apply caution.
Practical guidance: Do not start nattokinase while on Xarelto unless your prescriber agrees. Separating doses by time does not meaningfully reduce this risk because the interaction is due to overlapping effects which can last a long period of time. Avoid stacking with other agents that can increase bleeding risk such as aspirin, NSAIDs like ibuprofen, or high dose fish oil, unless directed by your clinician.
About Nattokinase
Nattokinase is an enzyme derived from natto, a traditional Japanese food made by fermenting soybeans with Bacillus subtilis. It has fibrinolytic activity, which means it helps break down fibrin, a protein involved in clot formation.
Nattokinase is marketed for cardiovascular wellness and healthy circulation, but clinical evidence for disease prevention outcomes remains limited and products vary in strength and standardization.
Final Words
The combination of nattokinase and Xarelto may increase bleeding risk. Discuss this with your prescriber before using nattokinase and consider safer alternatives that fit your goals. If you decide together to use any supplement, choose a reputable brand and monitor closely for bleeding symptoms.
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References & sources
Glossary — Terms in This Answer
- Anticoagulant
- A medication or substance that reduces the blood's ability to form clots.
- Nattokinase
- An enzyme derived from fermented soybeans that has blood-thinning and clot-dissolving properties.
- Xarelto
- A prescription anticoagulant medication (also known as rivaroxaban) used to prevent blood clots.
- Fibrinolytic
- Having the ability to break down fibrin, a protein that forms the structure of blood clots.
- Fibrin
- A protein in the blood that forms the mesh-like structure of clots.
- Antiplatelets
- Medications or substances that prevent platelets from clumping together to form clots.
- NSAIDs
- Non-steroidal anti-inflammatory drugs like ibuprofen that can also increase bleeding risk.
- Bacillus subtilis
- A bacterium used to ferment soybeans in the traditional Japanese food natto.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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