NutriStack
Apixaban and Nattokinase, a caution.
Nattokinase is a fibrinolytic enzyme that degrades fibrin and reduces clotting factor levels. Combined with apixaban's factor Xa inhibition, the additive effects substantially raise bleeding risk. Case reports describe intracerebral and intra-abdominal hemorrhage when nattokinase is added to other antithrombotics.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Apixaban and Nattokinase
- 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 fibrinolytic enzyme that degrades fibrin and reduces clotting factor levels. Combined with apixaban's factor Xa inhibition, the additive effects substantially raise bleeding risk. Case reports describe intracerebral and intra-abdominal hemorrhage when nattokinase is added to other antithrombotics.
Mechanism. Nattokinase, a serine protease from fermented soybeans, directly cleaves fibrin and activates plasmin-mediated fibrinolysis. It also reduces plasma fibrinogen, factor VII, and factor VIII levels. These effects compound apixaban's inhibition of factor Xa.
Recommendation. Do not combine nattokinase with apixaban. If you have been taking both, stop the nattokinase and call your prescriber, especially if you notice 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 Apixaban and Nattokinase 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.
Check your full routine
One pair was the worked example. NutriStack runs every pair in your stack at once.
Drop in your supplements and prescriptions and the public database surfaces every interaction, synergy, timing rule, and contraindication, every one linked to its primary source.