Nattokinase has seen a spike in interest in recent years as increasing numbers of studies have identified the potential for nattokinase to be used as a safe and effective blood thinner. While it may not initially seem valuable to have a blood thinner with an all-natural profile and a low risk of contraindications, most blood thinners currently on the market do have a hefty list of side effects, and can prove difficult to take in conjunction with other medications. What exactly does the science say? Is nattokinase truly a powerful way to prevent blood clots and reduce cardiovascular diseases without any real adverse effects, or is it yet another dietary supplement with a lot of hype and no true anti-coagulation profile? 

We'll get to the root of the true nature of nattokinase and the many clinical studies that have been conducted to determine its efficacy for blood clots and other cardiovascular and blood vessel related illnesses, but first, we will take a close look at oral nattokinase, including what it is and how it works. 

What Is Nattokinase?

For the as-yet uninitiated, nattokinase is the word used to describe an enzyme found in natto, a dish traditionally found in Japan, made up of boiled and fermented soybeans. This traditional Japanese food is fermented with bacillus subtilis, a specific type of bacteria that is said to boost fibrinolytic activity in the food, leading to the development of the fibrinolytic enzyme now recognized as nattokinase.

The longevity enjoyed by Japanese populations as a whole has long been a source of intrigue and rigorous study, and some researchers have determined that the consumption of natto is at least partially responsible. This popular soybean food, also called vegetable cheese natto, is far more than a savory dish to be enjoyed; the effect of nattokinase on blood pressure, blood viscosity, and overall cardiovascular health is substantial and without adverse effects, which can explain some of the robust health enjoyed by many Japanese populations, whose doses of nattokinase have flown under the radar as simple health foods. 

Now that we have established that nattokinase is an enzyme produced after boiled soybeans have been fermented with bacillus subtilis, it is important to identify the different actions nattokinase is capable of producing. Nattokinase is an enzyme that functions as a tissue plasminogen activator, or an enzyme that prevents blood clotting and possesses fibrinolytic effects. In human studies, this means that the activity in plasma is positively affected by the activity of nattokinase, leading to the more efficient delivery of blood throughout the body. Even a single dose of nattokinase can deliver these powerhouse effects of nattokinase and lead to improved blood pressure and a reduction in blood clot size. Regular doses of nattokinase can be used to return blood pressure levels to a normal range, and nattokinase intervention has been implicated as a contributor to neuroprotective effects and favorable health effects concerning virtually all aspects of cardiovascular and circulatory health. 

healthy blood pressure with nattokinase fine usa

How does it work as a blood thinner?

Oral nattokinase functions well as a blood thinner because it contains the enzyme nattokinase (also called NK), which has thrombolytic (or blood thinning) effects. Natto extract prevents thrombus formation and intimal thickening by ensuring that blood is thin and able to travel freely throughout the blood vessels, positively impacting both diastolic and systolic blood pressure, and preventing blood cell aggregation in blood vessels. Nattokinase has been used as an oral supplement for serious blood-related conditions, including deep vein thrombosis, cardiovascular disease, and diseases of the blood vessels.  

Recent research has determined that the molecular weight of nattokinase does indicate the presence of fibrinolytic activity, leading to antihypertensive, anti-atherosclerotic, lipid-lowering, antiplatelet, and even neuroprotective effects. In short, the levels of fibrinogen in this particular type of dietary supplementation far exceeds prescription blood thinners in the beneficial effects being provided, and effects in patients extend far beyond simple cardiovascular health and the prevention of thrombus formation. Reduced side effects compared to similar pharmaceutical interventions render this type of fibrinolytic therapy an invaluable tool in the arsenal of cardiovascular professionals. As an anticoagulant agent and fibrinolytic agent, the thrombolytic activities of NK can help maintain normal levels of vitamin K in the body and reduce the risks of disease and harm caused by high levels of vitamin K. 

The antiplatelet effects of  the pro-fibrinolytic enzyme nattokinase can make the difference between requiring a mechanical prosthesis following a blood clot or recovery, because nattokinase effectively breaks up the proteins and components that make up blood clots in the body, regardless of the precise origin. Human studies have determined that the activity of nattokinase functions both as a supportive intervention, not unlike the effects of aspirin, and an active treatment; in other words, NK's thrombolytic activities and antiplatelet effects can both prevent the onset of issues like blood clots in healthy subjects and treat existing conditions like an already-established blood clot, hypertension, and more. 

What Does Science Say About Nattokinase as a Blood Thinner?

A mounting body of evidence has suggested that natto extract, or nattokinase, is an effective blood thinner, a single dose on par with similar doses of blood thinning medications intended to function as either anticoagulant agents or fibrinolytic agents for the treatment and prevention of thrombosis. Using a daily dose of natto extract is not currently recommended across the board by medical professionals, but the increasing number of studies evaluating its effects on intimal thickening, systolic blood pressure, clot formation, and other cardiovascular and blood vessel related illnesses has increased its value as a potential treatment for human subjects in need of alternative, supplemental, or even replacement fibrinolytic therapy. Some of the scientific studies conducted on nattokinase include the following: 

Nattokinase was evaluated as a potential treatment on animals in a pilot study far before it was administered via a daily dose to people in order to prevent intimal thickening and other vascular concerns, and those initial studies yielded incredible results. One, in particular, determined that bacillus subtilis natto possessed potent fibrinolytic activity for both dogs and rat models. When it was administered to dogs as a thrombosis model, nattokinase dissolved the clot within five hours and restored normal blood flow. In rat studies, thrombolytic activity was the most effective preventative for intimal thickening and blockages in the carotid and femoral artery, making bacillus natto an ideal intervention for several blood conditions as demonstrated by the injury model in rat studies. 

Multiple studies have determined that NK has potent fibrinolytic and antithrombotic activity, and serves as an effective antiplatelet/anticoagulant for the prevention of thrombosis, heart disease, and ischemic stroke. This makes it a potentially valuable intervention for a host of health concerns without the many potentially negative side effects in patients so often attached to standard pharmaceutical intervention. Whether a patient has a mechanical valve, has had an aortic valve replacement, or is simply at risk for thrombosis, NK may be able to positively impact cardiovascular and general vascular health, improving blood circulation and dramatically reducing the risk of blood clotting. While studies with human volunteers are certainly not enough to counteract long-standing medical advice, as increasing studies support the value of NK as a cardiovascular health intervention, more and more medical professionals are encouraging its use. 

In perhaps one of its most substantial sources of value, this study determined that nattokinase does not merely prevent blood clotting and destroy existing blood clots, nor does it simply act as a regulator of systolic and diastolic blood pressure. Instead, nattokinase has a plethora of positive effects on human volunteers, extending beyond cardiovascular health, without significant side effects. Why is this such an exciting feature of nattokinase? Most medications that have been developed to function as a tissue plasminogen activator, to treat endothelial injury, or support cardiovascular health following damage to blood vessels such as the femoral artery, or major heart attacks come with a slew of potential side effects, some of which require additional types of medication to manage those side effects. The effects of nattokinase supplementation include aid for endothelial injury, cardiovascular support following significant surgeries like aortic valve replacements, prevention of ischemic stroke or reductions to the risk of stroke, and the reduction of elevated blood pressure without deleterious side effects.  


Nattokinase is a powerful antithrombotic agent that can have profound beneficial effects on cardiovascular diseases and overall blood flow, without the hazards and side effects that often accompany prescription blood thinners. A form of dietary supplementation, subtilis bacillus natto can be taken as a whole food addition to your diet, or in the form of powder or pills. The effects of nattokinase supplementation include the potential to reduce the risks of stroke-ischaemic stroke and more--in human studies and in rat models. Nattokinase intervention is able to prevent stroke in patients with existing heart conditions and risk factors by increasing blood flow, pare down blood viscosity to help return blood pressure levels to a normal range, and maintain a steady flow of blood to maintain a healthy level of circulation throughout the body. With favorable health effects and reduced side effects when compared to its pharmacological counterparts, nattokinase has been shown in laboratory studies to offer a powerful intervention with benefits for thrombosis, stroke prevention, cardiovascular health, blood circulation, and even healthy coagulation. 

Systemic enzyme supplements like nattokinase often rely on anecdotal evidence to support their use, but NK has enjoyed a strong enough surge of popularity in recent years to warrant a host of studies evaluating its value as a heart health intervention. With direct evidence in lab studies to support benefits for thrombosis, CVD, the risk of stroke, and more, without the carcinogenic effects often found in other medications, NK may be counted among the most valuable discoveries to be applied to heart and blood vessel health to support general health, reduce the risk of stroke in patients, and return CVD complications to a healthy baseline.

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