Nattokinase (NSK-SD®): A Simple Guide to This High-Potency Fibrinolytic Enzyme
If you’ve been looking into supplements for circulation and healthy blood flow, you may have come across nattokinase. Here is an overview of Nattokinase (NSK-SD®)—what it is, why it’s discussed in the context of cardiovascular wellness, and its ingredient list.
What is nattokinase?
Nattokinase is a natural fibrinolytic enzyme extracted from purified natto, a traditional Japanese fermented food. Natto is made from fermented soybeans, and nattokinase is a key compound that has made natto a focus in wellness research.
What does “fibrinolytic enzyme” mean?
“Fibrinolytic” refers to the body’s process of breaking down fibrin. Fibrin is a blood-clotting protein involved in normal clotting and healing. Nattokinase is studied for its potential to support the body’s clotting and fibrinolytic processes and help maintain healthy blood flow.*
In other words, the conversation around nattokinase is about supporting the body’s natural balance, helping keep blood flow moving smoothly while respecting its built-in clotting mechanisms.*
Why the potency matters: FU explained
On nattokinase labels, you’ll often see FU, which stands for fibrinolytic units. This product provides:
50 mg nattokinase
with an active enzyme potency of 20,000 FU/gram
FU expresses enzyme activity, not just ingredient weight, so two products with the same “mg” can differ in potency.
Ingredients list (One Capsule Contains)
Nattokinase† (active enzyme at 20,000 FU/gram) — 50 mg
Other Ingredients: Microcrystalline cellulose, hydroxypropyl methylcellulose (vegetable capsule), L-leucine.
Contains: Soy.
Does Not Contain: Milk, eggs, fish, shellfish, tree nuts, peanuts, wheat.
Important safety notes (please don’t skip)
Because nattokinase is linked to fibrin breakdown and blood flow support, it comes with extra precautions.
This product is contraindicated for individuals:
with a history of bleeding tendency, or
with conditions associated with bleeding.
It should be used only under the supervision of a healthcare practitioner, especially if you are taking:
anticoagulant (blood-thinning) medications, or
blood pressure medications.
Also: Keep out of reach of children.
Storage
Keep tightly closed in a cool, dry place.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
