A Single-Dose of Oral Nattokinase Potentiates Thrombolysis and Anti-Coagulation Profiles

This small Japanese RCT tested whether a single 2,000 FU dose of nattokinase — administered to 12 healthy men — acutely altered coagulation and fibrinolysis markers.

Within hours of ingestion, nattokinase raised D-dimer and fibrin degradation products (markers of active fibrinolysis) while reducing Factor VIII activity and prolonging aPTT, indicating simultaneous anticoagulant effects. All changes remained within normal physiological ranges, suggesting the effects were pharmacologically meaningful but not clinically dangerous in healthy individuals.

The study confirms that nattokinase has measurable acute pharmacological activity on the coagulation cascade in living humans — resolving a basic question about whether the enzyme survives oral ingestion and reaches the circulation in active form. But 12 subjects over a few hours is insufficient to address what matters clinically: whether these transient biomarker shifts translate to reduced thrombotic events in patients with established cardiovascular disease.

We rate the evidence moderate. Well-designed pharmacokinetic work in a tiny sample; it characterizes the mechanism and confirms bioavailability but cannot support clinical claims about cardiovascular event reduction.