Nattokinase may support healthy blood clotting and heart health

Published: 11-Nov-2026

Research suggests nattokinase may help break down fibrin clots and reduce key coagulation factors associated with cardiovascular disease

In late October, National Football League (NFL) star quarterback Jalen Hurts had to abruptly end his season after suffering a minor injury while playing in London. He developed blood clots in both lungs after being hit in the calf during a game and then flying home. His main treatment is taking anticoagulant (blood-thinner) medications.

Hurts’ condition has brought “blood clots” to the forefront of consciousness, with many wondering how they can reduce their risk, especially before a flight.

In a normal, healthy response to injury or bleeding, fibrin molecules intertwine to form long fibrous chains that entangle red blood cells and platelets (clotting) at the site of the injury. But, as a check and balance to this process, fibrinolysis (the breakdown of fibrin) prevents blood clots from growing beyond the point of usefulness. However, when fibrin isn’t adequately degraded by anticlotting mechanisms such as plasmin production (the primary fibrinolytic enzyme), the undissolved clots can contribute to downstream effects such as heart attacks and strokes.

Nattokinase, a serine proteinase from Bacillus subtilis considered one of the most active functional ingredients in natto (a fermented soy food), may be a powerful natural agent to manage healthy blood clotting responses and protect heart health.

Nattokinase as NSK-SD® from JBSL-USA has been shown to degrade fibrin clots both directly and indirectly. Lab tests indicate NSK-SD® dissolves fibrin six times more effectively than plasmin. NSK-SD® also targets fibrin indirectly by affecting plasminogen activator activity, which is the beginning step of plasmin production.

Three key coagulation factors – fibrinogen, factor VII and factor VIII – are also associated with an increased risk of cardiovascular disease (CVD). Fibrinogen is a consistent and independent risk factor related to cardiovascular disease (CVD), and research also indicates that factors VII and VIII are highly related to an increased risk of CVD.

Researchers hypothesised that consuming nattokinase could reduce fibrinogen, factor VII and factor VIII. In the study, both healthy and cardiovascular-risk participants took two capsules of nattokinase (2,000 fibrinolysis units per capsule) daily for two months. Significant time effects were observed in the change from baseline of fibrinogen, factor VII and factor VIII, suggesting that plasma levels continuously declined during the study period.

After two months, fibrinogen, factor VII and factor VIII decreased by 9%, 14% and 17%, respectively, for healthy participants, and by 7%, 13% and 19%, respectively, for the CR group. The researchers concluded, “Nattokinase could be considered as a CVD nutraceutical by decreasing plasma levels of fibrinogen, factor VII, and factor VIII.” 1

An earlier small trial on 12 adults reported that supplementation with nattokinase produced a gradual enhancement of fibrinolytic activity in the plasma. 2

Importantly, laboratory work shows that NSK-SD® nattokinase does not inhibit the formation of fibrin from fibrinogen, so it does not inhibit the formation of blood clots in response to injury.

NSK-SD® nattokinase is a solid choice for heart health supplements that address healthy clotting, a niche opportunity.

References

Hsia et al. Nattokinase decreases plasma levels of fibrinogen, factor VII, and factor VIII in human subjects. Nutrition Research 29 (2009) 190–196.
Sumi et al. Enhancement of the fibrinolytic activity in plasma by oral administration of nattokinase. Acta Haematologica 1990; 84: 139–143.