NutriStack
Nattokinase and Rivaroxaban, a caution.
Nattokinase is a direct fibrinolytic enzyme that also reduces clotting factor levels. Combined with rivaroxaban's factor Xa inhibition, the additive effect substantially raises bleeding risk. Reports describe intracerebral and intra-abdominal hemorrhage with nattokinase plus other antithrombotics.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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From the interaction database
What the row says.
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At a glance
- Substances
- Nattokinase and Rivaroxaban
- Pair type
- Caution
- Evidence (highest tier)
- Emerging
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Emerging evidence
Caution
What is happening. Nattokinase is a direct fibrinolytic enzyme that also reduces clotting factor levels. Combined with rivaroxaban's factor Xa inhibition, the additive effect substantially raises bleeding risk. Reports describe intracerebral and intra-abdominal hemorrhage with nattokinase plus other antithrombotics.
Mechanism. Nattokinase is a serine protease that directly cleaves fibrin and activates plasminogen, plus reducing plasma fibrinogen, factor VII, and factor VIII. These mechanisms compound rivaroxaban's factor Xa inhibition.
Recommendation. Do not combine nattokinase with rivaroxaban. If you have been taking both, stop the nattokinase and contact your prescriber, especially if you notice any unusual bruising or bleeding.
Sources (2)
- Chang YY, Liu JS, Lai SL, Wu HS, Lan MY. Cerebellar hemorrhage provoked by combined use of nattokinase and aspirin in a patient with cerebral microbleeds. Intern Med. 2008;47(5):467-9. PMID 18310985
- Elahi MM, Choi CH, Konda S, Shake JG. Consequence of patient substitution of nattokinase for warfarin after aortic valve replacement with a mechanical prosthesis. Proc (Bayl Univ Med Cent). 2015;28(1):81-2. PMID 25552810
Stack Score
How this pair moves the number.
Effect on the composite score
If both Nattokinase and Rivaroxaban are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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