Summary
Health benefits of nattokinase supplements:
Nattokinase supplements have been promoted for cardiovascular benefits. However, the clinical evidence is weak for reduction of clots (although a reduction in blood clotting factors has been demonstrated) and for reducing blood pressure, cholesterol, triglycerides, and the progression of atherosclerosis (see What It Does).
How to choose a nattokinase supplement:
When choosing a nattokinase supplement, it is important to look for one that lists its enzyme activity, which will be in FU (fibrin degradation or fibrinolytic units). Listing just the amount of enzyme in milligrams doesn't tell you enough, since not all nattokinase is equally active. Look for a product that provides at least 1,000 to 2,000 FU per pill or unit (see What It Is). Also, check that ConsumerLab.com or another reputable independent 3rd party has verified the enzyme activity (see What CL Found and How Products Were Evaluated).
Best nattokinase supplement:
ConsumerLab’s tests showed that only 5 of 8 nattokinase supplements provided their listed amounts of nattokinase enzyme activity within a reasonable margin, with two providing much less and one providing much more. Among those that passed testing, one provided exceptional value at reasonable dosing and was selected as CL’s Top Pick for nattokinase.
Nattokinase supplements tested included those by Allergy Research Group, Doctor’s Best, Double Wood, NOW, Nutricost, and Toku Flow, as well as Nattovena (Arthur Andrew Medical) and NSK-SD (Pure Encapsulations).
Nattokinase safety and side effects:
Short-term use of nattokinase supplements is generally well-tolerated, but should be used with caution with blood-thinners and blood-pressure lowering medication (see Concerns and Cautions). Nattokinase may also increase bleeding due to trauma or surgery. Many nattokinase supplements contain soy and should not be used by people with an allergy to soy (see the last column of the Results Table to find out which claim soy.) Be aware that nattokinase itself can also cause severe allergic reactions in some people.
