Nattokinase Improves Blood Flow by Inhibiting Platelet Aggregation and Thrombus Formation

This animal study explored a second mechanism by which nattokinase might “thin the blood” — not by dissolving clots, but by inhibiting platelets, the cells that initiate them.

In a rodent model, nattokinase inhibited platelet aggregation triggered by collagen and thrombin, suppressed thromboxane formation, and dose-dependently delayed or prevented arterial clotting — effects the authors likened to aspirin. It suggests a dual antiplatelet-and-fibrinolytic action.

The implications cut both ways and the evidence is thin. Antiplatelet activity in a handful of animals is far from proof of human benefit, and — as the case reports of bleeding in this library show — any genuine antiplatelet effect also raises a safety concern, especially alongside other blood thinners.

We rate the evidence limited. It is small-scale animal work on mechanism; it neither establishes cardiovascular benefit nor should reassure about safety, given the bleeding signals seen in human case reports.