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📰Read the full Nattokinase evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ Anticoagulant + nattokinase = serious bleeding risk [1]
⚠ NOT a warfarin/DOAC substitute — self-treating is dangerous [1]
⚠ Natto food = high K2 (affects warfarin). Use K-removed supplement [1]
⚠ Stop 2+ weeks before surgery (fibrinolytic) [1]
ℹ️ Not obtained from food. Not applicable — this is not obtained from food in meaningful amounts; supplementation is the practical route.
🔬 Lab interpreter
Recommended test
Blood pressure
Blood pressure
Reference range / target
Reduction
Reduction
~3 mmHg expected [2].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
Nattokinase has REAL fibrinolytic activity — it dissolves fibrin. BP meta-analysis: ~3 mmHg. BUT: NOT a substitute for prescribed anticoagulants. DANGEROUS to self-treat thromboembolic conditions. Anticoagulant + nattokinase = serious bleeding risk. Supplements must be vitamin K-removed (natto food has ~500 µg K2) [1] [2].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
AVOID — fibrinolytic, bleeding risk [1].
👦 Pediatric: See guidance
No data [1].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: On empty stomach (away from food for systemic absorption) [1].
💊 With food: Empty stomach preferred [1].
🚫 Avoid: Anticoagulants. Antiplatelets. Pre-surgery. Pregnancy [1].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Nattokinase capsules (vitamin K-removed)', 'preferred', 'Purified enzyme. K2 removed. 2,000 FU per capsule typical [1].'] | Standard | Check label | |
| ['Natto (whole food)', '', 'Contains nattokinase BUT also very high vitamin K2 — problematic for anticoagulant patients [1].'] | Standard | Check label |
3 Common questions
Is nattokinase a natural blood thinner? ▼
It has genuine fibrinolytic activity — it dissolves fibrin. But it is NOT a substitute for prescribed anticoagulants. Self-treating AFib, DVT, or other thromboembolic conditions with nattokinase instead of warfarin/DOACs is DANGEROUS [1].
Nattokinase vs natto food? ▼
Nattokinase supplements have vitamin K2 REMOVED. Natto food contains both nattokinase AND very high K2 (~500 µg per serving — would counteract warfarin). If on anticoagulants: supplements only, not natto food [1].
Can I take nattokinase with aspirin? ▼
CAUTION — additive anticoagulation/antiplatelet. Increases bleeding risk. Discuss with physician [1].
4 Clinical evidence
Strong
Fibrinolytic activity: nattokinase directly degrades fibrin in vitro — well-characterized enzyme [1]. Natto contains very high vitamin K2 — separate from purified nattokinase supplements [1]. HIGH
Moderate
Blood pressure: meta-analysis of 5 RCTs — SBP ~3 mmHg reduction [2]. Fibrinolytic/blood flow: improved blood viscosity in some trials [1]. DVT prevention (long flights): one trial positive for leg edema reduction [1]. MODERATE
Insufficient
5 Safety, toxicity & adverse events
Absolute contraindications
✕ Active bleeding, recent surgery or hemorrhagic stroke
Relative
⚠ Concurrent anticoagulants/antiplatelets — additive bleeding risk (important)
⚠ Discontinue before surgery/dental work
⚠ Uncontrolled hypertension
⚠ Soy allergy depending on source
🚩 Red flags
● Patient on anticoagulant + nattokinase — SERIOUS bleeding risk [1]
● Patient self-treating AFib/DVT with nattokinase instead of Rx — dangerous [1]
● Pre-surgery — stop 2+ weeks before [1]
6 Interactions
Drug interactions
Anticoagulants (warfarin, DOACs) Major
Mechanism: Additive fibrinolytic + anticoagulant effects. [1]
Effect: Serious bleeding risk. [1]
Action: AVOID combination [1].
Antiplatelets (aspirin, clopidogrel) Moderate
Mechanism: Additive anticoagulation. [1]
Effect: Increased bleeding. [1]
Action: Caution. Discuss with physician [1].
Supplement synergies
CoQ10 · 100–200 mg CoQ10
Cardiovascular support without anticoagulant interaction [1].
Cardiovascular support without anticoagulant interaction [1].
7 Regulatory
Japan: Widely used supplement. Functional food [1].
United States: Dietary supplement [1].
8 US supplement products
54
on-market products containing Nattokinase (NIH DSLD)
Brands carrying Nattokinase (31)
Click a brand to see its Nattokinase products.
9 Frequently paired with
10 Cite this page
Vancouver: Pkhakadze G. Nattokinase — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Aug 15]. Available from: https://supplement.ge/ingredients/nattokinase/
APA 7th: Pkhakadze, G. (2026). Nattokinase — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/nattokinase/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: February 2027
References: 2 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "Nattokinase — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/nattokinase/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG