• Fermented soybeans, Flite Tabs, natto, natto extract, nattokinase, NK, NSK II, NSK-SD, subtilisin NAT.

• Natto is a traditional Japanese food, prepared by fermenting boiled soybeans with the bacterium Bacillus subtilis. Nattokinase is an enzyme, which breaks down protein, and is purified from the cheese-like natto. Nattokinase was discovered in 1980 by a researcher who was trying to identify a natural agent that could successfully dissolve clots.
• People throughout Asia have consumed soybeans in a variety of traditional foods (including natto) for over 1,000 years. Due to their possible contribution to the observed low rates of heart disease in Asian countries, soy products such as natto have recently attracted attention in the West. As a result, nattokinase is a popular health food supplement.
• Nattokinase has been reported to have blood-thinning effects. Recently, research has indicated that nattokinase may have potential in the treatment of vein clots, or deep venous thrombosis (DVT), and high blood pressure, when used in combination with the standard therapies for these conditions.

• Angina (chest pain), atherosclerosis (clogged arteries), bone loss, cholesterol (lowering), chronic fatigue syndrome, endometriosis, eye disorders (pharmacologic vitreolysis, posterior vitreous detachment (PVD)), fibromyalgia, hemorrhoids, infertility, inflammation (chronic), muscle spasm, pain, peripheral vascular disease, rheumatism (soft tissue), stroke (noncardiac origin), tissue oxygenation, uterine fibroids, varicose veins, vision problems, wound healing.

Adults (18 years and older)

• Manufacturers recommend that nattokinase be given by mouth at a dose of 100 milligrams three times daily. Other recommended doses range from 2,000 to 6,000 fibrinolytic units (FU). A fibrinolytic unit is a measure of the ability to break down the protein fibrin, a component of blood clots.
• For high blood pressure, the following has been taken: one capsule of NSK-II (Japan Bio Sciences Laboratories Company Ltd., Japan; containing 2,000 FU/capsule) by mouth daily for eight weeks; two capsules of NSK-II by mouth daily for four weeks; a freeze-dried extract (80% ethanol; equivalent to 200 grams of natto and 6,400 FU) by mouth daily for four consecutive days.
• For vein clots (deep venous thrombosis (DVT)), two capsules of Flite Tabs (Aidan, Tempe, AZ; containing 150 milligrams of pinokinase (Pycnogenol® and nattokinase)) has been taken by mouth with 250 milliliters of water, two hours before a flight and six hours later.

Children (under 18 years old)

• There is no proven safe or effective dose for nattokinase in children.

Allergies

• Avoid with known allergy or hypersensitivity to natto, nattokinase, soybean (Glycine max), or soy-based products.

Side Effects and Warnings

• Natto has been consumed in regions of Japan for over 1,000 years, suggesting that it and nattokinase are likely safe when consumed in food amounts.
• Nattokinase may increase the risk of bleeding. Caution is advised in patients with bleeding disorders, such as cerebral microangiopathy, or in those taking drugs, herbs, or supplements that may increase the risk of bleeding. Dosing adjustments may be necessary.
• A single case of brain hemorrhage has been reported. Although not well studied in humans, hemorrhage in the retina of the eye has been reported in experimental studies.
• Some nattokinase supplements contain vitamin K, which may work against the effects of blood thinners like warfarin (Coumadin®).
• Nattokinase may cause easy bruising and changes in the retina.
• Nattokinase may cause low blood pressure. Caution is advised in patients taking drugs, herbs or supplements that lower blood pressure.
• Avoid in pregnant or breastfeeding women due to a lack of available scientific evidence.
• Avoid with known allergy or hypersensitivity to natto, nattokinase, soybean (Glycine max), or soy-based products.

Pregnancy and Breastfeeding

• Avoid in pregnant or breastfeeding women due to a lack of available scientific evidence.

Interactions with Drugs

• Nattokinase may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®). Some natto and nattokinase supplements contain vitamin K, which may work against the effects of anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin.
• Nattokinase may cause low blood pressure. Caution is advised in patients taking drugs that lower blood pressure.

Interactions with Herbs and Dietary Supplements

• Nattokinase may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases. Some natto and nattokinase supplements contain vitamin K, which may work against the effects of some agents that increase the risk of bleeding.
• Nattokinase may cause low blood pressure. Caution is advised in patients taking herbs or supplements that lower blood pressure.

• This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

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