Nattokinase enzyme supplement, benefit, side effects, safety, dosage, clinical uses
Information on nattokinase supplement and its interactions with blood thinners such as Coumadin, Plavix, and aspirin
August 17 2019 by Ray Sahelian, M.D.

Nattokinase is an enzyme isolated from the vegetable cheese Natto; a typical and popular soybean food in the Japanese diet. Nattokinase has been found to have blood clot dissolving abilities and prevents the aggregation of red blood cells. Another enzyme becoming more popular, this one from the silk worm, is serrapeptase. Both nattokinase and serrapeptase should only be used under the guidance of a health care provider. Combining nattokinase and an anticoagulant, such as aspirin, may lead to internal bleeding in some patients.

Discuss with your health care professional before nattokinase use, especially if you are taking anti-coagulants, aspirin, Coumadin or other medicines or herbs that thin the blood.

Purchase Nattokinase enzyme, Serrapeptase enzyme or to see a list of hundreds of high quality supplements
Suggested Use: As a dietary supplement, take 1 nattokinase capsule as directed by a healthcare practitioner. It may be taken with or without food. Use under medical supervision. Nattokinase is contraindicated in any condition associated with bleeding or combined with blood thinning agents such as warfarin (Coumadin), aspirin, or other blood thinners.

Nattokinase side effects, safety and risks and danger
No significant nattokinase side effects have yet been reported in the medical literature when used without other anticoagulants. However, this does not mean that nattokinase is side effect free, it just means that we don't have enough human trials to know all the benefits and risks with nattokinase enzyme treatment. One action of this natural substance is as a blood thinner, hence those on Coumadin, aspirin, or other anticoagulants need to be careful and discuss with their doctor the use of this supplement. Using nattokinase with warfarin or aspirin could enhance bleeding risk.

Cerebellar hemorrhage provoked by combined use of nattokinase and aspirin in a patient with cerebral microbleeds.
Intern Med. 2008.
We report a patient, having used aspirin for secondary stroke prevention, who had an acute cerebellar hemorrhage after taking nattokinase 400 mg daily for 7 consecutive days. In addition to the hemorrhagic lesion multiple microbleeds were demonstrated on brain MR images. We suggest that this blood thinner may increase risk of intracerebral hemorrhage in patients who have bleeding-prone cerebral microangiopathy and are receiving other antithrombotic agents at the same time.

Food Chem Toxicol. 2015. Toxicological Assessment of Nattokinase Derived from Bacillus subtilis var. natto. Nattokinase is a fibrinolytic enzyme produced by the bacterial strain Bacillus subtilis var. natto, which plays a central role in the fermentation of soybeans into the popular Japanese food natto. Recent studies have reported on the potential anticoagulatory and antihypertensive effects of nattokinase administration in humans, with no indication of adverse effects. To evaluate the safety of nattokinase in a more comprehensive manner, several GLP-compliant studies in rodents and human volunteers have been conducted with the enzyme product, NSK-SD (Japan Bio Science Laboratory Co., Ltd., Japan). Nattokinase was non-mutagenic and non-clastogenic in vitro, and no adverse effects were observed in 28-day and 90-day subchronic toxicity studies conducted in Sprague-Dawley rats at doses up to 167 mg/kg-day and 1000 mg/kg-day, respectively. Mice inoculated with 7.55 x 108 CFU of the enzyme-producing bacterial strain showed no signs of toxicity or residual tissue concentrations of viable bacteria. Additionally consumption of 10 mg/kg-day nattokinase for 4 weeks was well tolerated in healthy human volunteers.

Does nattokinase pass through the blood - brain barrier?
    I suspect it does since hemorrhage has been reported in the brain with the use of this blood thinner in combination with aspirin.

I am a provider in an internal medicine office. We had a patient with Factor V Leiden who developed a large pulmonary embolism. He was started on Coumadin during hospitalization. He then went home and saw his herbalist who started him on nattokinase. Three weeks after starting the natural blood thinner and stopping his Coumadin on his own, he arrived as a call in to the office with chest pain and shortness of breath. Within 10 minutes of arrival he was dead from a large sadal pulmonary embolism. In my opinion, it is reckless to suggest patient with factor V Leiden, factor S, Factor C or any other clotting disorder would be able to use nattokinase as a blood thinner. Kinase (Streptokinase) as implied may help break up a clot but would not thin the blood. Patients who are placed on TPA, Streptokinase are still placed on Heparin in the hospital.

I take 3 blood pressure meds and recently tried nattokinase after recommendation from family members. I was fine but one day I developed a large hematoma on my arm. Not life threatening. then a few days later had some other unusual bruising. I felt it was too much blood thinner for me and stopped taking it.

Commonly prescribed blood thinners include:
Rivaroxaban (Xarelto), Dabigatran (Pradaxa), Apixaban (Eliquis), Heparin (various brands), and Warfarin (Coumadin). Also aspirin and Plavix (clopidrogel).

Q. I am taking one baby aspirin, nattokinase and one serrapeptase per day. Is this dangerous?
   A. A doctor would need to know much more than this limited medical information before making a recommendation. Generally, when more than one blood thinner is combined, the risk for bleeding increases significantly.

Mechanisms of action
Nattokinase inactivates plasminogen activator inhibitor type 1 and potentiates fibrinolytic activity. In other words, it could dissolve fibrin. Fibrin is a protein involved in the clotting of blood that is polymerised to form a "mesh" that forms a hemostatic plug or clot (in conjunction with platelets). Fibrin is made from fibrinogen, a soluble plasma glycoprotein synthesized by the liver. Nattokinase prevents aggregation of red blood cells.

Lab Anim Res. Dec 2013. Nattokinase improves blood flow by inhibiting platelet aggregation and thrombus formation. The effects of nattokinase on the in vitro platelet aggregation and in vivo thrombosis were investigated in comparison with aspirin. Rabbit platelet-rich plasma was incubated with nattokinase and aggregation inducers collagen and thrombin, and the platelet aggregation rate was analyzed. Nattokinase significantly inhibited both the collagen- and thrombin-induced platelet aggregations. Nattokinase also reduced thromboxane B2 formation from collagen-activated platelets in a concentration-dependent manner. Rats were orally administered with nattokinase for 1 week, and their carotid arteries were exposed. Arterial thrombosis was induced by applying 35% FeCl3-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Nattokinase delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 160 mg/kg. In addition, a high dose (500 mg/kg) of nattokinase fully prevented the occlusion, as achieved with aspirin (30 mg/kg). The results indicate that nattokinase extracted from fermented soybean inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is suggested that nattokinase could be a good candidate without adverse effects for the improvement of blood flow.

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Coumadin ( warfarin ) interaction and caution
We have been asked many times regarding the interaction of nattokinase supplement use and warfarin. Can they be taken together or can one substitute for the other? Here is a typical question.

I am a stroke survivor and since i had my stroke I have been extremely wary about taking ant kind of vitamin supplement. Recently my doctor has given me the green light to take some CO-Q10 as well as a multiple vitamin. i was looking at your information about the supplement nattokinase, and its benefits and side effects. I have been thinking about taking this product after first having my dr. review the info. i have been on Coumadin since my stroke in 2005. Currently I have been getting some blood clots in my legs. My dr. advised me that he wants to keep my INR level thinner then normal to help keep from having another one. He wants the INR level to be at least 3.0 to 3.5. I am wondering if I started to take nattokinase and other herbal supplements like hawthorn will it keep my blood thin enough to accomplish this task and my dependency on Coumadin could be eliminated.
    Each person is different on how they respond to nattokinase and other supplements. It is impossible to predict your response. Your doctor may wish to read this article and then decide if he or she wants to add this supplement to your existing regimen while perhaps decreasing the dose of the Coumadin. Unfortunately, we have not seen any clinical studies regarding the combination of low dose nattokinase and low dose Coumadin to determine how they interact and whet the appropriate combination dosages would be. Therefore, close monitoring is required if the Coumadin dose is being reduced while the nattokinase dose started. The best option is to do the transition is tiny dose changes, even if it involves initially taking part of a nattokinase capsule.

My father, an 83 year old, was recently put on Coumadin as a blood thinner. They found a problem with his heart rhythm and also found a blocked artery. From the time he was put on the drug, he has become "not himself". I think that it’s the drug that they put him on personally, and I would like to get it out of him as soon as possible. I got an email about this nattokinase supplement and was curious about it. My problem is, how do I talk to his health care provider about switching to a nattokinase supplement instead of the tried and true pharmaceuticals? I don't pretend to be an expert, but I do want to do what is best for my Dad. How would YOU like to be approached on this?
    You may wish to show this page to his doctor who can then decide on an appropriate action.

I would like to know if there is any research on the safety of using nattokinase instead of coumadin for persons with the St. Joseph's mechanical valve.
    I am not aware of such research.

For the record, for the past month I have been taking 2 capsules of nattokinase per day, each capsule rated at 2,000 FU, in place of 10mg warfarin per day as prescribed by my cardiologist. I found my reactions to warfarin lurched erratically from an INR value of 1.2 up to 8.5 on this dose, and caused bleeding eyeballs and bruising. I just had an INR done and it was down to 1 on the nattokinase, with a prothrombin time of 9.7 seconds (both considered within the normal range). I do not know if warfarin and nattokinase have any correlation in terms of what clotting factors can be measured, as far as I can find out there have been no studies done on this. My cardiologist thinks I am at risk of a stroke due to atrial fibrillation if I take nattokinase (which she had not heard of) instead of the prescription blood thinner.

I've been on coumadin / warfarin for almost 30 years, and my doctor believes this might have led to the osteoporosis I was diagnosed with 2 years ago. So we want to reduce my intake if possible. He suggested using nattokinase, but the anticoagulation clinic told me that the effect won't show up on the pro-time (INR) meter because it works on factors that the meter can't measure. I'm told I need to keep my prothrombin time within the therapeutic zone, but if I can't measure the effect of the nattokinase we won't know where I am.

Fish oil interaction
Q. I have been doing my research on Natto because I have very high fibrinogen in my blood that will be prone to clotting. I would love to take something that would dissolve the fibrin and hopefully loosen up the platelets to avoid a clot. Is taking Fish Oil with Natto the same as taking Aspirin? I don't take any medication except for Thyroid and Carlson's liquid Fish Oil
   A. Fish oils do thin the blood and hence one should be cautious with dosages and take these natural medicines with medical supervision. It is difficult to compare the potency of fish oil and aspirin.

Do you know of any research that compares nattokinase with plavix following stent placement? I am having mental confusion with Plavix and have stopped taking it but would like to try nattokinase as a substitute but my cardiologist says he has no knowledge of the product. However he is open to read any research I can find on the issue.
    It's difficult to say since the benefits of Plavix versus its side effects have not been fully evaluated. It is also not fully clear whether Plavix offers benefits that are superior to a cheap medication such as aspirin. I have not seen head to head comparisons between Plavix and nattokinase so I can't say whether nattokinase can replace the use of Plavix. It is possible that it could in some people.

Blood clotting
Effects of nattokinase, a pro-fibrinolytic enzyme, on red blood cell aggregation and whole blood viscosity.
Clin Hemorheol Microcirc. 2006. Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
A fibrinolytic enzyme, termed nattokinase, can be extracted from natto; the enzyme is a subtilisin-like serine protease composed of 275 amino acid residues and has a molecular weight of 27.7 kDa. In vitro and in vivo studies have consistently demonstrated the potent pro-fibrinolytic effect of the enzyme. Blood samples were incubated with nattokinase for 30 minutes at 37 degrees C. Our in vitro results showed a significant, dose-dependent decrease of RBC aggregation and low-shear viscosity, with these beneficial effects evident at concentrations similar to those achieved in previous in vivo animal trials. Our preliminary data thus indicate positive in vitro hemorheological effects of nattokinase, and suggest its potential value as a therapeutic agent and the need for additional studies and clinical trials.

Dietary supplementation of fermented soybean, natto, suppresses intimal thickening and modulates the lysis of mural thrombi after endothelial injury in rat femoral artery.
Life Sci. 2003. Department of Pharmacology, Hamamatsu University School of Medicine, Handayama, Hamamatsu City, Shizuoka, Japan.
We have previously demonstrated that natto extracts containing nattokinase inactivate plasminogen activator inhibitor type 1 and then potentiates fibrinolytic activity. In the present study, we investigated the effects of dietary supplementation with natto extracts on neointima formation and on thrombolysis at the site of endothelial injury. Endothelial damage in the rat femoral artery was induced by intravenous injection of rose bengal followed by focal irradiation by transluminal green light. Dietary natto extracts supplementation containing nattokinase of 50 or 100 CU/body was started 3 weeks before endothelial injury and then continued for another 3 weeks. Intimal thickening in animals given supplementation was significantly suppressed compared with controls, In conclusion, dietary natto-extracts supplementation suppressed intimal thickening produced by endothelial injury in rat femoral artery.

Blood pressure and hypertension
Is it true that nattokinase enzyme is not a safe supplement for people with high blood pressure?
    One study shows nattokinase enzyme can reduce blood pressure.

Effects of nattokinase on blood pressure: a randomized, controlled trial.
Hypertension Res. 2008: Yonsei University Research Institute of Science for Aging, Department of Food and Nutrition, Yonsei University, and Department of Family Medicine, Mizmedi Hospital, Seoul, Korea.
In a randomized, double-blind, placebo-controlled trial, 86 participants ranging from 20 to 80 years of age with an initial untreated systolic blood pressure of 130 to 159 mmHg received nattokinase (2,000 FU/capsule) or a placebo capsule for 8 weeks. Seventy-three subjects completed the protocol. Compared with the control group, the net changes in systolic blood pressure and diastolic blood pressure were -5 mmHg and -3 mmHg, respectively, after the 8-week intervention. The corresponding net change in renin activity was -1.1 ng/mL/h for the nattokinase group compared with the control group. In conclusion, nattokinase supplementation resulted in a reduction in systolic blood pressure and diastolic blood pressure. These findings suggest that increased intake of nattokinase may play an important role in preventing and treating hypertension.

I am interested in this product. I have read that it is very good for improving blood circulation and lowering blood pressure. I need to improve blood circulation but I already have low blood pressure. Does this product have the potential to regulate blood pressure or rather will it most likely lower blood pressure?
    I am not sure how this product will influence blood pressure in those who are normal range or have low blood pressure. It does seem to be helpful in those who have hypertension.

Hello, I've been taking nattokinase for about 2 months now and it has dropped my hypertension to almost normal levels.

I have read that nattokinase holds great promise for senile dementia. Is this true?
   I am not aware of such studies.

Blood levels
Altern Ther Health Med. 2013. A pilot study on the serum pharmacokinetics of nattokinase in humans following a single, oral, daily dose. Nattokinase is a serine protease and is derived from natto, a traditional Japanese, fermented, soybean food meal. Multiple authors have described the significant fibrinolytic, antithrombotic, and antihypertensive effects of natto. It has been growing in popularity for use as a dietary supplement for the benefit of cardiovascular health. Little is known regarding the pharmacokinetic and pharmacodynamic properties of this enzyme, and the bioavailability is currently unknown. Subjects were instructed to orally ingest a single capsule containing a known concentration of nattokinase immediately following a baseline blood draw. Subsequent blood draws occurred over a 24-h period. Administration of nattokinase occurred orally with the ingestion of a single daily dose (2000 FU) of nattokinase. Capsules, each containing approximately 100 mg of nattokinase, in softgel form (NSK-SD, Japan Bio Science Laboratory, Osaka, Japan), were used in the study. Peak serum levels of nattokinase were observed at approximately 13.3 h ± 2.5 h postdose.

Natto consumption and blood thinning
Prev Nutr Food Sci. 2012. The antithrombotic and fibrinolytic effect of natto in hypercholesterolemia rats. Antithrombotic and fibrinolytic activity of natto was evaluated on platelet aggregation in vitro and in vivo. Natto showed inhibitory effects on platelet aggregation induced by adenosine 5'diphosphate (ADP) and collagen. Orally administered natto also showed fibrinolytic activity in hypercholesterolemia rats. Normal levels of natto, when administered for four weeks, shortened euglobulin clot lysis time (ECLT) and prolonged partial thromboplastin time (PATT) significantly compared to non-treated group. In addition, the natto treatment decreased total cholesterol in serum. These results showed that intake of normal levels of natto can elicit antithrombotic and fibrinolytic effects, suggesting its consumption may improve blood circulation.

Q. I just read online that it is ok to take Natto if you are on a low dose aspirin, you say different. I just started taking a little bit less than a teaspoon of the fermented soybeans with my aspirin yesterday ( I spread it out.) How would I know if I have internal bleeding?
   A. I have not seen enough studies with natto itself to know how much of it can effect blood thinning. It does thin the blood but I am not sure the amount it takes to have a significant effect. I think small amounts would not be significant but I am not certain.

Nattokinase research studies
Dietary supplementation with fermented soybeans suppresses intimal thickening.
Nutrition. 2003.
Although soy foods have been consumed for more than 1000 years, it is only in the past 20 y that they have made inroads into Western diets. We investigated the effect of dietary supplementation with natto extracts produced from fermented soybeans on intimal thickening of arteries after vessel endothelial denudation. Natto extracts include nattokinase, a potent fibrinolytic enzyme having four times greater fibrinolytic activity than plasmin. Intimal thickening was induced in the femoral arteries by intravenous infusion of rose bengal followed by focal irradiation with a transluminal green light. Nattokinase extract supplementation was started 3 wk before endothelial injury and continued for another 3 wk after. Nattokinase supplementation suppressed intimal thickening compared with the control group. Nattokinase shortened euglobulin clot lysis time, suggesting that their thrombolytic activities were enhanced. These findings suggest that nattokinase, because of its thrombolytic activity, suppress intimal thickening after vascular injury as a result of the inhibition of mural thrombi formation.

Thrombolytic effect of nattokinase on a chemically induced thrombosis model in rat.
Biol Pharm Bull. 1995.
Nattokinase is a new fibrinolytic enzyme which cleaves directly cross-linked fibrin in vitro. In this study, we investigated the thrombolytic effect of nattokinase on a thrombus in the common carotid artery of rat in which the endothelial cells of the vessel wall were injured by acetic acid. When a section of occluded vessel was stained for CD61 antigen by immunofluorescence utilizing a monoclonal antibody, the antigen was localized around the surface of the occluded blood vessels. This result suggests that the occlusive thrombosis was caused by platelet aggregation. In addition, thrombolysis with urokinase (UK; 50000 IU/kg, i.v.) or tissue plasminogen activator (tPA; 13300 IU/kg, i.v.) in our model was observed to restore the blood flow over a 60 min monitoring period. The results indicate that our chemically induced model is useful for screening and evaluating a thrombolytic agent. We evaluated the thrombolytic activity of nattokinase using this model and compared it with fibrino(geno)lytic enzyme, plasmin or elastase. On a molar basis, the recovery of the arterial blood flow with nattokinase, plasmin and elastase were 62%, 15% and 0%, respectively. The results indicate that the thrombolytic activity of nattokinase is stronger than that of plasmin or elastase in vivo.

Transport of nattokinase across the rat intestinal tract.
Biol Pharm Bull. 1995.
Intraduodenal administration of nattokinase at a dose of 80 mg/kg, resulted in the degradation of fibrinogen in plasma suggesting transport of nattokinase across the intestinal tract in normal rats. The action of nattokinase on the cleavage of fibrinogen in the plasma from blood samples drawn at intervals after intraduodenal administration of the enzyme was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting analysis with an anti-fibrinogen gamma chain antibody. The 270 kDa fragment carrying antigenic sites for the binding of the anti-fibrinogen gamma chain antibody appeared within 0.5 h and was then degraded gradually to a 105 kDa fragment via a 200 kDa fragment. This suggests that fibrinogen was degraded to a 105 kDa fragment via several intermediates (270 and 200 kDa). In parallel with the degradation process, plasma recalcification times were remarkably prolonged NK was also detected in the plasma from blood samples drawn 3 and 5 h after administration of the enzyme by SDS-PAGE and Western blotting analysis with an anti-nattokinase antibody. The results indicate that nattokinase is absorbed from the rat intestinal tract and that nattokinase cleaves fibrinogen in plasma after intraduodenal administration of the enzyme.

Purification and characterization of a strong fibrinolytic enzyme nattokinase in the vegetable cheese natto, a popular soybean fermented food in Japan.
Biochem Biophys Res Commun. 1993.
A strong fibrinolytic enzyme nattokinase was purified from the vegetable cheese natto. Nattokinase was extracted from natto with saline and isolated by sequential use of hydrophobic chromatography. The isolated protein gave a single sharp band on SDS-PAGE either before or after reduction. The sequence consisted of a total 275 amino acid residues (M.W = 27,728) and exhibited a high homology with the subtilisins. The purified nattokinase digested not only fibrin but also several synthetic substrates. The results indicate that nattokinase is a subtilisin-like serine protease.

Enhancement of the fibrinolytic activity in plasma by oral administration of nattokinase.
Acta Haematol. 1990.
It was confirmed that oral administration of nattokinase (or natto) produced a mild and frequent enhancement of the fibrinolytic activity in the plasma, as indicated by the fibrinolytic parameters, and the production of tissue plasminogen activator. Nattokinase capsules were also administered orally to dogs with experimentally induced thrombosis, and lysis of the thrombi was observed by angiography. The results obtained suggest that nattokinase represents a possible substance for use not only in the treatment of embolism but also in the prevention of the disease, since nattokinase has a proven safety and can be mass produced.

Secretory expression of a heterologous nattokinase in Lactococcus lactis.
Appl Microbiol Biotechnol. 2007. Center for Metabolic Engineering of Microorganisms, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China.
Nattokinase has been reported as an oral health product for the prevention of atherosclerosis. We developed a novel strategy to express a nattokinase from Bacillus subtilis in a live delivery vehicle, Lactococcus lactis. Promoter P( nisZ) and signal peptide SP(Usp) were used for inducible and secretory expression of nattokinase in L. lactis. Western blotting analysis demonstrated that nattokinase was successfully expressed, and about 94% of the enzyme was secreted to the culture. The recombinant nattokinase showed potent fibrinolytic activity, equivalent to 41.7 urokinase units per milliliter culture. Expression and delivery of such a fibrinolytic enzyme in the food-grade vehicle L. lactis would facilitate the widespread application of nattokinase in the control and prevention of thrombosis diseases.

If a person is allergic to soy, would nattokinase pose a problem? Some say that it is only proteins that cause allergies and since the natural blood thinner is an enzyme, it would not. Yet, many of the nattokinase preparations marketed are in a base of soy oil and soy lecithin…. which would be a whole other issue besides the nattokinase enzyme, itself.
   It's a good question, I really don't know the answer but I would think that nattokinase itself would not cause an allergy, but perhaps if it is in soy base, the product could.

Q.  Is it safe to use nattokinase while breastfeeding? The dose of nattokinase that I have on hand is 100mg per capsule.
   A. There's very little human research on this topic and we don't really know how well it goes through breast milk. To be on the safe side, it would be best not to use it during pregnancy.

Q. Is nattokinase enzyme helpful in fibroids?
   A. I don't know, I have not seen any studies relating its use in those with fibroids.

Q.  I know you stated that nattokinase is a blood clot remover. Could it break up or remove blocked arteries and veins?
   A. There is not enough human research on nattokinase and blood clots or blocked arteries for us to know this answer at this time, but the initial nattokinase research regarding blood clot dissolving potential looks promising.

Q.  I am a health food store owner, ordered mattokinase for a gentleman that was supposed to have by bypass surgery, He is also on a vegan diet, He has been taking the nattokinase medicine for a few months and when he went to the doctor last week, they told him he did not have to have bypass surgery. He is still on the plan but he wants to know how long does he have to take the nattokinase medicine.
   A. This is interesting. We really are not in a position to say how long a person should or should not take a nattokinase supplement. That is the decision of their doctor.

Q. Why is nattokinase enzyme sold separately from fermented soy? If I consume fermented soy supplements ( natto ), wouldn't I also be consuming the nattokinase enzyme found in it?
   A. Hi, sure you could get nattokinase from fermented soy, but it may not be found nearly enough. This is the same as vitamin C. Let's say you wish to have 1000 mg of vitamin C, that means you would have to ingest a dozen or more oranges. We are not sure how much nattokinase is in an ounce of fermented soy, a lot depends on how it is prepared.

Q. 2 years ago I had a central retinal vein occlusion, thank God my vision has been restored almost completely, except for a tiny area in my right eye. Would it be advisable to take nattokinase enzyme to dissolve the clot?
   A. We have not seen any studies regarding nattokinase enzyme use and central retinal vein occlusion, hence we can't advise.

I read a comment on your nattokinase page that someone had a central retinal artery occlusion and had regained their sight. Could you put me in touch with that person or send them my email address so that they may contact me? I have had the same problem (CRAO) and would appreciate any information regarding how my sight may be regained if at all possible.
   Sorry but we do not keep email addresses, we get dozens of emails a day and once read they are deleted.

Q. is it true that nattokinase is not safe for people with high blood pressure and/or who are taking medication for it? if so, why?
   A. We have not seen any research that indicate nattokinase should or should not be used by those on blood pressure medication or those who have hypertension.

Q. My mom had a recent TIA as a result of her pulmonary valve stenosis. She was released from the hospital yesterday. I would like to have my Mom use nattokinase instead of Coumadin for obvious reasons. However I am concerned about your warnings and my doctor says nattokinase research is inconclusive, so he can’t advise. Mom has atrial fibrillation due to a mitral valve stenosis (one doctor calls it atrial valve stenosis). The result is that blood pools in the lung and there is danger of throwing clots from the pooled blood. Of course, the other problem with the pooled blood is that it goes out into the lung cavity in the form of fluid, which must be drawn off using a diuretic, Lasix. Mom is also on Lopressor to control the heart rate, and in the process it lowers blood pressure. Ma was on a drug similar to Coumadin while in the hospital, but when she was discharged, the doctor put her on aspirin, while waiting for a decision from the family as to whether to switch to Coumadin or nattokinaise. Obviously, it would be one or the other, NOT both! The doctor warns that on aspirin alone, the danger of having another stroke is 80% over the next 2 months, so we need to find a suitable substitute. The reason that aspirin is ineffective is that it is a blood thinner, in the sense that it prevents platelets from sticking together. However, the source of her clots is not sticky platelets, but because the blood is pooling in the lungs, forming clots. She requires a substance that will prevent such clots from forming and will dissolve clots already formed. Please provide whatever information you can on nattokinaise and its viability in this sort of case.
   A. There has not been enough human research with nattokinase and heart valve stenosis and subsequent clot formation to determine whether nattokinase is effective in these conditions or whether it is a substitute for Coumadin or other drugs. This is a complicated situation and we cannot get involved in diagnosis or treatment suggestions. Her doctor may wish to read this nattokinase page and make a decision.

Q. I read that nattokinase can reverse or reduce plaque buildup and fatty deposits in the arteries. Do you know if that is that true? If so, can you tell me now much nattokinase needs to be taken daily for this to be effective? Is nattokinase NSK-SD better? And how long does it normally take before there is significant reduction of plaque buildup and fatty deposits?
   A. These are good questions but we still have not seen enough human studies with nattokinase to have a clear idea of the effectiveness of this enzyme in terms of atherosclerosis or blood thinning. There is no research comparing different brands, hence we can't say Nattokinase NSH-SD is better or worse than other brands. There's too little human research available with nattokinase to know the ideal dosage and length of use or its overall effectiveness.

Q. I have been taking nattokinase for years to lower fibrinogen, and I think it works. Today I had my blood drawn for a fibrinogen test, and the technician asked me if I was taking a blood thinner and mentioned two drugs. I said no, but asked why she was asking. She said be cause if I was she would have to prepare the sample differently for sending to the lab. I asked her if nattokinase would make a difference. She had never heard of it. I asked her to call the lab the check it out. She did and was told that they never heard of it. Later, I was picking up a prescription and asked the pharmacist, and she had never heard of it and had nothing in her database about it either. Seems to me that if you are not supposed to take blood thinners with it, and it must have blood thinning properties and might need to be handled at the lab the same as a blood thinner. What do you think? Could my results be off because it was not handled a certain way? Would it be higher or lower?
   A. There's a lot we still need to learn about nattokinase and how it influences various blood coagulation proteins and factors when taken as a supplement. But research is being done and within a few years we should have a more complete understanding. In the meantime, it does appear that nattokinase breaks down firbrinogen and prevent red blood cells from aggregating, and it does have blood thinning properties. How potent nattokinase is when compared to Coumadin? I don't know.

Q. What do you think of taking a nattokinase supplement before a long flight to prevent blood clotting?
   A. This is an interesting idea. However, whether it offers any advantages over aspirin is not clear to me.

Q. Could you please tell me if this product has been found to be safe for pregnant women and their developing baby?
   A. We are not aware of any research with nattokinase in women who are pregnant. It is preferable to be on the safe side and not take nattokinase during pregnancy. 

Q. Could you tell me if there has been any new research or studies on nattokinase? It seems that all your posted questions are pretty much answered with the same answer; There’s not enough nattokinase research. I’m very interested in this product but am not convinced there is enough evidence that would sway my decision to use it. I have had 2 stents put in and have factor 5 liden blood protein abnormality. I would like to find a proven product that would prevent clots.
   A. We will update our site as more nattokinase studies are published. Until then we can't say too much. Sorry. We don't want to make false promises if studies do not support them.

Q. Are there any reliable studies regarding any possible adverse reaction when taking nattokinase in a person with a known or possible penicillin allergy.
   A. We have not seen such studies. A search on Medline with the keywords nattokinase and penicillin reveals no articles published on this topic.

Q. Must products with nattokinase be enteric-coated capsules?
   A. We have not seen any studies comparing nattokinase supplement that are enteric coated to those that are not.

Q. Since there are people taking nattokinase in an effort to reduce blood clotting, why isn't the standard prothrombin time test used to measure it's affect? This would seem to resolve any doubts, at no risk to the patients, and little expense. It works, or it doesn't, and with what variables.
   A. Sure, prothrombin time would be a good way to measure one's clotting status before use and during treatment.

Q. How is natto made?
   A. Natto is made by steaming or boiling soybeans and then fermenting this with a bacterium called Bacillus subtilis natto. Natto contains a high amount of vitamin K2.

Q. Does the use of nattokinase supplement lower blood pressure?
   A. I have not seen studies focusing on the use of nattokinase as a treatment for hypertension, but I have read articles by a few doctors who claim that the use of nattokinase had a mild effect in lowering blood pressure. However, caution is advised since nattokinase is also a blood thinner and problems may arise when used in combination with aspirin or other blood thinners.

I am a practicing chiropractor and mother of several boys. A family history of Factor V Leiden deficiency with a positive MTHFR and Factor II variance. My oldest does heparin injections and middle son is on Coumadin. My 8 year old has yet to be tested however the pediatric hematologist is certain he has at least one genetic variance. So our dilemma is the starting of full contact football and not proactively putting him on a thinner. So a pharmacist recommended nattokinase. Can children use this product?
    I have not seen studies with nattokinase in children so I don't know what kind of benefits or side effects would occur, what the appropriate nattokinase dose would be and what kind of bleeding problems may occur if engaging in contact sports while on nattokinase blood thinner. There are many unknowns so it is difficult to predict the outcome.

Do you think I could take nattokinase one dose per day with serrapeptase one dose per day? I have been diagnosed with blocked carotid arteries 50% on the left side 20% on the right. I discontinued using serrapeptase when I began the nattokinase. I was using the serrapeptase for my lower back pain and it was helping tremendously along with myofascial release. I think my back pain has gotten worse since I quit the serrapeptase. What is your opinion?
    Nattokinase enzyme and serrapeptase enzyme are potent supplements that should be used carefully with the knowledge or supervision of a health care provider. I am not aware of studies that have looked into using both supplements together, so I don't know what kind of potential benefits or side effects would occur. Each person is different in how they respond to these enzyme supplements, therefore it is not possible to predict your response to nattokinase or serrapeptase in combination.

I know that nattokinase is considered a substitute for baby aspirin taken to prevent heart attacks, but I was wondering if there is any interaction between the two. Would taking both “thin” the blood too much? I ask because I take Bufferin for back pain (it works best for me of all the non-narcotic pain relievers) and wondered if I can also start taking nattokinase.
    There is not enough research to know whether nattokinase works as well as a baby aspirin to prevent heart attacks. Even in the case of aspirin, which has been studies a great deal, there is no consensus on the ideal dosage for heart attack prevention. There is a possibility that the combination of nattokinase and aspirin could thin the blood too much but this has to be evaluated on a case by case basis.

I have just read your question and answer section concerning nattokinase pills, and from a personal standpoint here is what I have done that is working for me for almost 3 years. I was on Plavix, 80mg of Lipitor, and Lisinopril, so dizzy 90% of the time that I would have to lie down on the ground, putting my feet up against something to hold them to where I would get adequate blood flow, so I closed my business thinking that my cardiologist, being a highly trained individual should know what she was doing. Big Mistake, I finally told my RN wife, I had had enough, so I dropped the cardiologist, and all medications, I had a roto rooter job in 1994, and if I died that was fine with me, as I had throat cancer in 2000, been clear since, so death was not a threat to me, anyway I started taking 2000iu or what ever the deal is on Nattokinase, have not been dizzy, feel better that I have felt in 20 years, I take herbs, lots of vitamins, this is now going on 3 years, I had Hypertension in the range of 210/100 even on all the meds, then it may run early of a morning to 80/52 just constantly unable to regulate my BP, for the last 3 years the only time it is irregular is when I get excited by thinking about how much money I paid that lady to screw me over at one of the major heart hospitals in Dallas Tx, I do still take my metoprolol and have since 1994, but you now have my take on nattokinase and what it has done to make my life, a 1000% better than it was prior to starting it.

Do you know that if taking natto supplement taking 2 capsule daily will cause any hiccup and bloating. i'm asking on behalf of my friend 60 yrs old and all the while don't have hiccup but since taking nattokinase supplement she used to have hiccup day and night. could you explain to me why is it so?
    I have not had reports of anyone else with these symptoms, so I don't know.

I take Nattokinase natural blood thinner. Have used it for two years. I require a pulse (pacemaker) shortly. Of course the medics want me to take Coumadin (warfarin) which I do not wish to take. My Cardio Doc. is "OK" with Nattokinase, except he says: The only thing he has against it is that it "may not be manufactured in the US" and therefore could possibly have things in it that wouldn't be in it if made say in China (He is Chinese! ! ) and says many "imports" have chemicals that aren't
allowed in US - that are not shown on the bottle - Do you know if the natural blood thinner you provide is made in the USA; or is it made in a foreign company. I buy mine from a mail order distributor (after studying about it for some time on the internet) but my distributor say's she doesn't know exactly where it is manufactured.
    We don't know where other products are made from other companies, but the one we provide is made in Japan.

Since nattokinse is made from soy, will taking it interfere with thyroid function if you have Hashimoto's thyroiditis? I've heard that people with this condition should avoid most forms of soy except for small (2 - 4 tsp.) amounts of fermented soy. Also, is a combination of natto and amla a good substitute for fish oil, co-q-10 products for cardio & vascular health? Any real studies done on these issues?
    One has to consume a great deal of soy for it to have any effect on thyroid function. There are many supplements that could be helpful for heart and vascular health and it is not easy to predict in any one individual which ones would be most helpful without knowing the full medical history, physical exam, and blood tests.

My 17 yr old son has inherited protein C deficiency, but has never had any clots or other symptoms. He plays football and wrestles. Of the men in our family with the disorder, symptoms usually start with a clotting event around age 20, followed by commencement of lifelong Coumadin therapy. Obviously our doctor does not want to start Coumadin until there is a clot because of the side effects. I have asked about using nattokinase as a prophylactic that may help avoid that 1st clot. Our Doctor says he would not be opposed. I am prepared that nattokinase may not be work, as long as it is not likely to cause harm. My question is whether if used alone it will increase his risk of bleeding, especially during contact sports? Doesn’t natto work in a way that on its own does not increase bleeding risk? What would be the lowest/ best effective dose?
   There are not enough long term studies with this substance to know for sure how well it would work in this condition and what the side effects would be in teenagers would are involved in contact sports. There just isn't enough good information on this enzyme to provide confident answers.

Q. I notice reading through the references that nattokinase has been measured in FU - fibrinolytic units and CU which I am not familiar with. Is there any conversion scale?
   A. According to one study, "A strong fibrinolytic activity was demonstrated in the vegetable cheese Natto, which is a typical soybean food eaten in Japan. The average activity was calculated at about 40 CU (plasma units)/g wet weight." I have come across one source that claims fibrinolytic activity of 40 CU is equal to 30 FU: fibrin degradation units but I can't yet be sure how reliable this is.

Q. I take nattokinase 3 x 100 mg per day due to atherosclerosis and one implanted has worked wonders for three years now... I take no pharmaceutical prescription medications.

I am a 57 year old male with Factor V and mthfr clotting disorders. I have had two DVTs and two superficial clots within the last four years. Otherwise, I am in good health and exercise regularly. My doctor put me on Coumadin after my 2nd DVT for the rest of my life and I am looking for an alternative. Do you have any experience using nattokinase with clotting disorders?
   At this time I do not.

Q. I am a cardiac surgeon. Nattokinase is a week PA-1 inhibitor, but a more potent form cultured in a low salinity medium (halotolerant B. Peptidase f) produces NKCP a secret patented form made in Northern Japan. We use it in a product called Vasculex. Warfarin (an aflatoxin) reduces the activity of prothrombin but can also promote vascular wall (arterial & venous) sclerosis, through vascular wall protein crosstalk disruption.

buy Nattokinase 2000 units fibrinolytic activity per pill
Nattokinase is a systemic enzyme isolated from the traditional Japanese soy food, natto. It has been shown to support healthy blood flow by assisting the circulatory clearing system of the body.

Supplement Facts
Serving Size: 1 capsule capsule
Serving Per Container: 90 servings
  Amount per serving % Daily Value
Nattokinase (Enzyme activity fibrinolytic units) 2,000 FU
†Daily Value not established.

Amount per serving
Nattokinase, providing 2,000 fibrin degradation units ( FU ) of activity per pill.

Q. Your site shows nattokinase 1 capsule per day. The directions on back of bottle of Drs Best says twice daily. Which is best one or two capsules for blood thinner.
   A. I prefer using low dosages but each person and each case is different, every person has different needs depending on diet, other medications, supplements and herbs used, and medical condition.