Nattokinase

Powerful fibrinolytic enzyme from fermented soybeans that supports circulation and cardiovascular health

Scientific nameNattokinase enzyme FormulaSerine protease enzyme Molecular weight27700 g/mol CAS133876-92-3

85 absorption score

6 safety / 10

40 USD per month

5 documented interactions

Check it against something

Moderate clinical significance

Nattokinase with:

57 out of 100

Needs attention Separate by 2-4 hours to avoid the interaction below.

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What it does

mechanism and evidence for each claim

Enhanced blood flow and circulation

Improves blood viscosity and flow throughout the body

Breaks down fibrin clots and reduces blood thickness Evidence A-grade 2-8 weeks

Natural fibrinolytic activity

Helps dissolve excess fibrin and blood clots

Direct fibrinolytic enzyme activity breaks down clots Evidence A-grade 4-12 hours

Blood pressure support

May help maintain healthy blood pressure levels

Improved circulation and reduced blood viscosity Evidence B-grade 4-8 weeks

Cardiovascular protection

Supports overall heart and vascular health

Reduces thrombotic risk and improves circulation Evidence B-grade 8-16 weeks

Reduced risk of thrombosis

May help prevent formation of dangerous blood clots

Fibrinolytic activity prevents clot formation Evidence B-grade Ongoing with regular use

Others take these for the same thing

Same goal, different mechanism — check any of them against this one

Coenzyme Q10 (CoQ10) Heart health & cellular energy 100-200mg A 10% Fish Oil (EPA/DHA) Heart & brain health 1-2g EPA/DHA A 85% Psyllium Husk Digestive health & cholesterol support 5-15g A 95% Calcium Citrate Superior absorption bone & heart health 500-1200 mg A 45% Taurine Cardiovascular & exercise support 1-3g A 95% L-Citrulline Athletic performance & circulation 3-8g A 95%

Every pair we checked

12 combinations scored by the engine

Nattokinase + Vitamin D3 May counteract some anticoagulant effects Needs attention 57

Nattokinase + Vitamin C (Ascorbic Acid) May counteract some anticoagulant effects Needs attention 57

Nattokinase + Calcium Carbonate High calcium may promote clotting Needs attention 58

Nattokinase + Caffeine No documented interaction either way No known interaction 70

Nattokinase + Creatine Monohydrate No documented interaction either way No known interaction 70

Nattokinase + Whey Protein No documented interaction either way No known interaction 70

Nattokinase + Lactase No documented interaction either way No known interaction 70

Nattokinase + Bovine Collagen No documented interaction either way No known interaction 70

Nattokinase + DHA No documented interaction either way No known interaction 70

Nattokinase + Turmeric No documented interaction either way No known interaction 70

Nattokinase + Coenzyme Q10 (CoQ10) Enhanced cardiovascular and cellular energy support Works better together 75

Nattokinase + Omega-3 + Curcumin + Vitamin D Triple Anti-Inflammatory Formula Enhanced cardiovascular and anti-inflammatory benefits Works better together 78

Dosage

Empty stomach

Daily2000-4000 FU

Circulation support2000-4000 FU daily

Cardiovascular prevention2000-4000 FU daily

Therapeutic4000-6000 FU daily with medical supervision

MaximumDo not exceed 6000 FU daily

When to expect it

First Effects4-12 hours for fibrinolytic activity

Peak Benefits8-16 weeks for cardiovascular and circulation benefits

Deficiency DevelopmentNot applicable - enzyme supplement

Toxicity OnsetMainly bleeding risk with high doses

How to measure it

$100-150

MarkerClotting times, platelet function, fibrinogen levels

OptimalNormal clotting parameters with improved circulation

Deficient belowNot applicable for enzyme supplement

FrequencyRegular monitoring if on anticoagulants or high doses

What people actually reported to the FDA

CAERS, 13 reports naming it as the suspect

Most reported effects

Dyspnoea 3

Hypersensitivity 2

Haemoglobin decreased 2

Hospitalisation 2

Cerebrovascular accident 2

Named as the suspect 13 reports of 22 that mention it at all

Serious outcome 79% hospitalisation, emergency room or worse

Hospitalization9

Visited Emergency Room7

Other Serious or Important Medical Event6

Reports are voluntary and unverified — they record what someone experienced while taking something, not what the compound caused. Counts skew towards products people take a lot of, and a serious outcome is more likely to be reported than a mild one, so these are not rates. How we filter them →

What actually reaches you

The label counts the carrier, your body does not

Absorption Very high 85 of 100 · best absorbed form of this compound

Delivered daily 2550 mg

Cost per 100 mg delivered $0.05 comparative — uses the absorption score, not a measured percentage

Works better with

3 documented

Omega 3 Fatty Acids

Enhanced cardiovascular and anti-inflammatory benefits

Complementary antiplatelet and anti-inflammatory effects · level B

Vitamin E

Additional cardiovascular protection

Antioxidant protection complements circulation benefits · level C

Coq10

Enhanced cardiovascular and cellular energy support

Complementary heart health and energy benefits · level C

What not to take with Nattokinase

2 documented

Vitamin K

May counteract some anticoagulant effects

Vitamin K promotes clotting, opposite to nattokinase · moderate significance

Calcium Excess

High calcium may promote clotting

Calcium is required for blood clotting cascade · mild significance

Medication interactions

Discuss these with a pharmacist before combining

anticoagulants-warfarin Major

Dangerous enhancement of bleeding risk

What to do: Avoid combination, consult physician

antiplatelet-agents Major

Increased bleeding tendency

What to do: Avoid combination or use with extreme caution

nsaids Moderate

Increased bleeding risk

What to do: Monitor for bleeding signs

Available forms

bioavailability compared

Enteric-Coated Nattokinase (2000-4000 FU) 85

Enteric-Coated Nattokinase (2000-4000 FU): Strong evidence, Powerful effects, Unique mechanism, Japanese tradition

Food sources

before you supplement

Natto (fermented soybeans) High nattokinase activity (1000-2000 FU/serving) · 80

Fermented soybean products Variable nattokinase content · 70

Nattokinase supplements Standardized FU content (2000-4000 FU) · 85

Not found in other foods Unique to fermented soy products · N/A

Too little

deficiency signs

Not applicable (enzyme supplement, not essential nutrient):
Conditions addressed by nattokinase:
Poor circulation and blood flow
Thick, viscous blood
Risk of thrombosis and clots
Cardiovascular disease risk
High blood pressure

Too much

toxicity signs

Primarily bleeding-related concerns:
Easy bruising and prolonged bleeding
Excessive bleeding during surgery or injury
Internal bleeding risk with high doses
Interaction with blood-thinning medications

Who benefits most

cardiovascular-prevention

Excellent for preventing blood clots and supporting heart health

2000-4000 FU daily

poor-circulation

Improves blood flow and reduces blood viscosity

2000-4000 FU daily

thrombosis-risk

May help prevent dangerous blood clot formation

2000-6000 FU daily with medical supervision

high-blood-pressure

May provide additional support for BP management

2000-4000 FU daily

aging-adults

Supports age-related cardiovascular health

2000 FU daily

Where to buy it

compare forms first

Look for Nattokinase at 2000-4000 FU per serving. The form that matters here is Enteric-Coated Nattokinase (2000-4000 FU).

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How it works

Direct fibrinolytic activity breaks down fibrin clots
Reduces blood viscosity and improves flow properties
Activates plasminogen to plasmin for clot dissolution
Inhibits platelet aggregation reducing clot formation
Enhances endothelial function and nitric oxide
Reduces inflammatory markers in blood vessels

Key findings

what the evidence supports

Highly effective fibrinolytic enzyme with strong clinical evidence
Significant benefits for circulation and cardiovascular health
High bleeding risk requires careful monitoring and medical supervision
Must be discontinued before any surgical procedures

Sources: NIH Examine.com · data reviewed 2026-08-02

Compiled by Denis, who maintains this database and holds no medical qualification — every figure here is sourced or derived, never asserted. How we calculate it →

Common questions

What are the benefits of Nattokinase?

Documented effects: Enhanced blood flow and circulation; Natural fibrinolytic activity; Blood pressure support; Cardiovascular protection. Improves blood viscosity and flow throughout the body

How much Nattokinase should you take per day?

The common daily range is 2000-4000 FU. By goal — circulation support: 2000-4000 FU daily; cardiovascular prevention: 2000-4000 FU daily; therapeutic: 4000-6000 FU daily with medical supervision; maximum: Do not exceed 6000 FU daily.

When is the best time to take Nattokinase?

Empty stomach. First effects are typically reported within 4-12 hours for fibrinolytic activity.

What are the side effects of Nattokinase?

At excessive doses: Primarily bleeding-related concerns:, Easy bruising and prolonged bleeding, Excessive bleeding during surgery or injury, Internal bleeding risk with high doses, Interaction with blood-thinning medications. Safety rating at normal doses is 6 out of 10.

What should you not take with Nattokinase?

Separate it from Vitamin K, Calcium Excess by two to four hours. May counteract some anticoagulant effects

Does Nattokinase interact with medications?

Documented interactions with anticoagulants-warfarin, antiplatelet-agents, nsaids. Discuss these with a pharmacist before combining.

How do you know if you need Nattokinase?

The marker is Clotting times, platelet function, fibrinogen levels, optimal range Normal clotting parameters with improved circulation. Common deficiency signs: Not applicable (enzyme supplement, not essential nutrient):, Conditions addressed by nattokinase:, Poor circulation and blood flow, Thick, viscous blood.

Taken for

52 Heart

Fish Oil (EPA/DHA) · EPA · Olive Oil Extract