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5 Benefits and Side Effects of Nattokinase (Be Careful With 6 Contraindications) [Updated Jan/2023]

Nattokinase is one of the most active functional components in natto. The most unique is that as a single compound, it has potential effects such as anti-thrombosis, anti-hypertension, anti-coagulation, anti-atherosclerosis, neuroprotection, etc.

Natto has long been used in folk medicine to treat cardiovascular diseases; nattokinase is believed to possess the same properties. While generally considered safe and tolerable, nattokinase may cause side effects and interact with certain medications.

In empirical medicine, is the use of nattokinase really effective? Whether there are side effects or contraindications, please refer to the text analysis for details.

What is Nattokinase?

Nattokinase is a serine protease purified and extracted from natto. Natto is a traditional Japanese food. It is made by inoculating Bacillus subtilis with boiled soybeans and then fermenting it.

In the study, it was found that nattokinase not only has fibrinolysis activity, but also can activate other fibrinolytic enzymes, such as pro-urokinase and tissue plasminogen activator.

Compared with other fibrinolytic drugs (urokinase, t-PA enzyme, streptokinase), it has the advantages of low side effects, low cost, long half-life, etc., and has the potential to be used as cardiovascular disease drugs and functional food additives.

How to use nattokinase? (dose)

Nattokinase activity is measured by the value of Fibrinolysis Units (FU). However, there is not enough evidence to confirm the optimal dose of oral nattokinase.

But research on humans tends to use about 2000 FU to 5000 FU (fibrinolytic units) per day

What are the benefits of Nattokinase?

1. Nattokinase can reduce thrombosis

Coagulation is formed by a series of chemical reactions between special blood cells (platelets) and proteins (coagulation factors) in the blood, and is an important defense mechanism of the human body.

Sometimes this process is abnormal, and abnormal blood clots (also called thrombus) appear in arteries or veins, which hinder blood flow to surrounding tissues.

Acute arterial thrombosis is the proximal cause of most myocardial infarctions (heart attacks) and about 80% of strokes.

An open-label clinical trial (targeted 45 adults) was divided into 3 groups, namely the healthy group, the cardiovascular group, and the dialysis group. All subjects took 2 nattokinase capsules (a single dosage of 2000 FU) for 2 months. Note 1

The results found that the coagulation factors related to cardiovascular diseases, such as fibrinogen, coagulation factor VII, and coagulation factor VIII, all continued to decline, and the decline in each group was similar.

Another double-blind, placebo-controlled trial (subject to 12 healthy young men) pointed out that the concentration of D-dimer and blood fibrin/fibrinogen degradation products in subjects who took nattokinase were increased, which was related to the activation of tissue-type plasminogen. Compared with the half-life of urokinase (t-PA) and urokinase in human blood, which is 4-20 minutes, its duration of action is longer (about 8 hours or more) . Note 2

*Conclusion: Oral nattokinase may be positively helpful in inhibiting thrombosis, but limited by the number of samples, more large trials are still needed to confirm its clinical benefits

2. Nattokinase prevents atherosclerosis

Atherosclerosis is a chronic disease in which arteries harden through the formation of plaque. The main risk factors include dyslipidemia, diabetes, smoking, high blood pressure and genetic abnormalities.

A randomized controlled trial (26-week period and 82 hyperlipidemia patients) was divided into two groups. One group was given a lipid-lowering drug: simvastatin (20 mg), and the other group was given nattokinase (daily dosage is 6000 FU). Note 3

After the test, it was found that both the medial common carotid artery intima thickness (CCA-IMT) and carotid plaque size decreased in both groups, but the magnitude was more significant in the nattokinase group.

In addition, blood lipid indexes such as TG, TC and LDL-C in the two groups all decreased, but the magnitude was more significant in the simvastatin group, while nattokinase could increase HDL-C.

*Conclusion: Oral nattokinase may be helpful in preventing atherosclerosis, but limited by the number of samples, more large-scale trials are still needed to confirm its clinical benefits.

3. Nattokinase benefits regulate blood pressure

Hypertension is a basic public health problem. In addition to coronary heart disease and stroke, its complications also include heart failure, peripheral vascular disease, renal impairment, retinal hemorrhage and visual impairment.

The number of deaths from hypertension in the world is about 7.5 million each year, accounting for 12.8% of the total deaths. It is estimated that by 2025, patients with hypertension will increase to 1.56 billion.

As to the nattokinase dosage for high blood pressure, a randomized, double-blind, placebo-controlled trial (subject to 86 patients with prehypertension or stage 1 hypertension) showed that oral nattokinase dosage of 2,000 FU for 8 weeks reduced blood pressure values ​​(systolic blood pressure -5.55 mmHg and diastolic pressure -2.84 mmHg) . Note 4

*Conclusion: Oral nattokinase may have a positive effect on blood pressure control, but due to the small number of samples, more large trials are still needed to confirm whether it has clinical benefits

4. Nattokinase benefits hyperlipidemia

Dyslipidemia, manifested as elevated low-density lipoprotein cholesterol (LDL-C), is the core of the development and progression of atherosclerosis. Atherosclerosis can be silent before triggering the first major cardiovascular event ten years.

In guidelines around the world, low-density lipoprotein cholesterol (LDL-C) is designated as the main treatment target for patients with dyslipidemia.

A randomized, double-blind, placebo-controlled, parallel-controlled study (for 6 months, with 47 patients with hyperlipidemia), divided into 3 groups, namely: nattokinase group, nattokinase combined with red yeast rice extract , Placebo. Note 5

It was found that the effect of single prescription (nattokinase) on blood lipids did not appear until the 6th month, while the compound prescription (nattokinase combined with red yeast rice extract) improved all blood lipid measurement indexes from the first month.

In addition, the blood lipid reduction rate of the compound formula is also better than that of the single formula. Related indicators include triglyceride (TG) 15%, total cholesterol (TC) 25%, low-density lipoprotein cholesterol (LDL-C) 41%, high-density lipoprotein cholesterol (HDL-C) 7.5%.

*Conclusion: Compared with the single prescription (Nattokinase), if the red yeast rice extract can be combined, it can bring better hyperlipidemia improvement effect

5. Nattokinase benefits nasal polyps

Nasal polyps is an inflammatory hyperplasia of the sinus tissues. Although it can be observed under a variety of clinical conditions, including: allergies, asthma, infections, fungi, cystic fibrosis, and aspirin sensitivity, it is accompanied by chronic sinusitis. Polyps are the most common.

According to the location and size of the polyps, the main symptoms of nasal polyps are nasal obstruction, runny nose and nasal discharge, loss or decrease of smell, taste changes, facial pain, etc.

An in vitro study indicated that nattokinase solution reduced the size of nasal polyp tissue through its fibrin-degrading properties and also reduced the viscosity of mucus and sputum compared to saline . Note 6

*Conclusion: In vitro studies have found that nattokinase can degrade nasal polyp tissue, but there is a lack of human trials and its effectiveness has yet to be confirmed


What are the nattokinase side effects?

Is nattokinase safe? Are there any nattokinase side effect? Nattokinase is a natural ingredient derived from natto. It has been a traditional Japanese diet for hundreds of years. It is extremely safe to consume from natto.

In the case of nattokinase supplements, short-term use (up to 6 months) at an appropriate dosage is usually safe,

Safety precautions (6 points of use taboo)

Even though there is not many side effects of nattokinase, we still need to be careful when using it.

  1. Do not use for pregnant, lactating women and underage children (because the relevant safety is unknown)
  2. Do not use for poor blood coagulation
  3. Do not use for two weeks before surgery (may increase the chance of excessive bleeding during or after surgery)
  4. Patients who are taking anticoagulants should not use it (may increase the risk of bleeding). The names of related drugs are: aspirin, clopidogrel, diclofenac, ibuprofen, naproxen, dalteparin, enoxaparin, heparin, warfarin
  5. Do not use blood pressure lowering drugs or patients with hypotension (because nattokinase has a blood pressure lowering effect)
  6. Do not use for poor liver and kidney function (because the relevant safety is unknown)

Where can I buy the highest quality Nattokinase that is recommended by most people?

Doctor's Best, Nattokinase, 2,000 FUs, 90 Veggie Caps

(Direct shipping from the United States / Worldwide delivery)

Product Tips

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Product Features:

Doctors Best is a well-known health care brand in the United States, known for its high quality, and ranks in the top three sales lists in all major pharmacy channels


Non-GM certification


Each capsule is available in doses up to 2,000 FU


Gluten Free


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