NutriStack
Grape Seed Extract and Nattokinase, a caution.
Both can reduce platelet aggregation or affect clotting, so combining them may additively increase bleeding risk.
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
- Grape Seed Extract and Nattokinase
- Pair type
- Caution
- Evidence (highest tier)
- Emerging
- Source citations
- 3 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Caution · Emerging evidence
Caution
What is happening. Both can reduce platelet aggregation or affect clotting, so combining them may additively increase bleeding risk.
Mechanism. Grape seed proanthocyanidins inhibit platelet aggregation while nattokinase has fibrinolytic and antithrombotic activity; the combined effect can shift hemostasis toward reduced clotting.
Recommendation. Use caution when combining, especially if taking anticoagulant or antiplatelet drugs, and discontinue before surgery; consult a clinician.
Sources (3)
- Vitseva O et al. Grape seed and skin extracts inhibit platelet function and release of reactive oxygen intermediates. J Cardiovasc Pharmacol. 2005;46(4):445-51. PMID 16160595
- Weng Y et al. Nattokinase: An Oral Antithrombotic Agent for the Prevention of Cardiovascular Disease. Int J Mol Sci. 2017;18(3). PMID 28264497
- Kurosawa Y et al. A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles. Sci Rep. 2015;5:11601. PMID 26109079
Stack Score
How this pair moves the number.
Effect on the composite score
If both Grape Seed Extract 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.
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