Quick answer: Nattokinase is an enzyme made during the fermentation of soybeans into natto. It is most often used as a supplement for general circulation and cardiovascular wellness, but it is not a medicine, it should not replace prescribed treatment, and people taking blood-thinning medicines or preparing for surgery should speak with a qualified health professional before using it.
At Healthy, we see nattokinase questions from New Zealanders who want a clear, practical way to compare products without overclaiming what a supplement can do. This guide explains what nattokinase is, why people use it, how to read a label, and what safety checks matter before you buy.
What is nattokinase?
Nattokinase is a proteolytic enzyme produced when Bacillus subtilis ferments soybeans into natto, a traditional Japanese food. Supplement brands usually supply it in capsules or tablets, with strength listed in fibrinolytic units, commonly written as FU.
Nattokinase is different from natto. Natto is the fermented food and may naturally contain vitamin K2. Nattokinase supplements are usually made to provide the enzyme in a measured amount, and some are formulated to be low in vitamin K2. Always check the label because formulas vary by brand.
Why people search for nattokinase
Most people look at nattokinase because they are interested in circulation, healthy blood flow, or broader heart health habits. The most balanced way to think about it is as one possible supplement within a wider plan that includes food choices, movement, sleep, stress support, and regular medical care when needed.
In the first step, we recommend comparing products by enzyme activity, ingredient quality, allergens, and suitability for your situation. You can browse existing nattokinase supplements or view our broader heart health collection while using the checklist below.
Evidence at a glance
Nattokinase has been studied for its effect on fibrin pathways, blood pressure markers, and related cardiovascular risk factors. Some small human studies and reviews suggest possible benefits for blood pressure or haemostatic markers, but the evidence is still not strong enough to treat nattokinase like a medicine or a replacement for prescribed care.
That matters because many online claims go too far. Nattokinase should not be described as a cure, an artery cleaner, a clot treatment, or a substitute for anticoagulant, antiplatelet, blood pressure, cholesterol, diabetes, or cardiovascular medicines. We recommend using cautious language and asking a health professional where medicines or diagnosed conditions are involved.
Who nattokinase may suit
Nattokinase may suit adults who are already focused on everyday cardiovascular wellness and want to compare a specific enzyme supplement. It may also appeal to people who prefer measured capsules over eating natto, especially if they want to know the listed FU amount per serve.
It is less suitable when the goal is urgent treatment, fast results, or managing a diagnosed cardiovascular condition without medical support. Any chest pain, shortness of breath, stroke symptoms, sudden swelling, unusual bleeding, or severe headache needs urgent medical advice rather than a supplement decision.
Who should avoid nattokinase or ask first?
Ask a doctor, pharmacist, or qualified clinician before using nattokinase if you take blood-thinning medicines, antiplatelet medicines, blood pressure medicines, or medicines for a heart, circulation, stroke, clotting, liver, kidney, or bleeding condition. Also ask first if you are pregnant, breastfeeding, trying to conceive, due for surgery or dental work, or have a history of easy bruising or bleeding.
Stop and seek advice if you notice unusual bruising, nosebleeds, bleeding gums, black stools, blood in urine, severe headache, dizziness, allergic symptoms, or anything that feels out of pattern for you. In New Zealand, suspected adverse reactions can also be reported through Medsafe pathways.
How to choose a nattokinase product in New Zealand
A good nattokinase comparison starts with the label, not the marketing claim. Look for the stated enzyme activity in FU, the amount per capsule or tablet, the suggested serving, the full ingredient list, allergen statements, and whether the product mentions soy, dairy, gluten, gelatin, or vitamin K2 content.
Quality markers to check
- FU activity: Look for a clear enzyme activity amount, not only milligrams.
- Serving directions: Follow the product label unless your health professional advises otherwise.
- Allergen suitability: Nattokinase is commonly linked with soy fermentation, so soy-sensitive people should check carefully.
- Capsule type: Vegetarians and vegans should check whether the capsule is plant based or gelatin based.
- Extra ingredients: Check whether the formula includes vitamin K2, serrapeptase, herbs, minerals, or other actives that may affect suitability.
- Brand transparency: Prefer clear labelling, batch information, and responsible claims over vague promises.
Dose, FU activity and timing
Many nattokinase labels focus on FU because this reflects enzyme activity. Milligrams tell you the weight of material in a capsule, but FU is usually more useful for comparing the activity stated by the brand. Different products use different serves, so compare total FU per suggested daily serving rather than capsule size alone.
There is no single best dose for every person. The right approach depends on age, medicines, health history, diet, and why you are considering it. We recommend following the label, avoiding stacking multiple blood-flow supplements without advice, and checking with a pharmacist or clinician when medicines are involved.
Natto, nattokinase and vitamin K2
Natto, nattokinase, and vitamin K2 are related, but they are not the same. Natto is the fermented soybean food. Nattokinase is an enzyme produced during fermentation. Vitamin K2 is a vitamin that can also be found in natto and some supplements.
This distinction matters most for people taking warfarin or other medicines where vitamin K intake may need to be consistent. Some nattokinase products are designed with low or no vitamin K2, but you should never assume. Check the label and ask your health professional if you use warfarin or have been told to monitor vitamin K intake.
How long does nattokinase take to work?
Nattokinase is not a quick-fix supplement. Research studies often assess markers over weeks, and individual experiences vary. For everyday wellness use, we recommend setting realistic expectations, tracking how you feel, and reviewing whether the product still makes sense after a consistent period of use.
Do not use nattokinase to delay medical care. If you are trying it alongside lifestyle changes, keep your usual check-ups, blood pressure checks, blood tests, and medicines as advised by your clinician.
FAQs
What does nattokinase do for your body?
Nattokinase is an enzyme studied for its effect on fibrin pathways and some cardiovascular markers. People commonly use it for circulation and heart health support, but it is not a treatment for clots, stroke, heart disease, or blocked arteries.
What are the negative side effects of nattokinase?
Possible concerns include bruising, bleeding, digestive upset, headache, dizziness, allergic reactions, and interactions with medicines that affect clotting or blood pressure. Stop using it and seek advice if you notice unusual bleeding or symptoms that worry you.
Are nattokinase and vitamin K2 the same thing?
No. Nattokinase is an enzyme produced during natto fermentation. Vitamin K2 is a vitamin that may also be present in natto. Some supplements contain one, the other, or both, so check the label carefully.
Can nattokinase clean arteries?
We would not describe nattokinase as cleaning arteries. Some research looks at cardiovascular markers, but nattokinase should not be used as a cure or substitute for medical care, prescribed medicine, cholesterol management, or blood pressure treatment.
Can nattokinase interact with medications or other supplements?
Yes. Nattokinase may not be suitable with anticoagulant medicines, antiplatelet medicines, blood pressure medicines, fibrinolytic medicines, or other supplements that may affect bleeding risk. Ask a doctor or pharmacist before combining products.
How long does it take for nattokinase to work?
There is no guaranteed timeline. Studies often look at changes over weeks, while personal responses vary. Use the product only as directed and review it with a health professional if you are taking medicines or monitoring a health condition.
How do you choose a good-quality nattokinase product in New Zealand?
Choose a product with clear FU activity, full ingredient disclosure, allergen information, sensible serving directions, and responsible claims. Avoid products that promise to cure disease, dissolve clots, or replace prescribed medicine.
What should you look for on a nattokinase label, including dose, form and additives?
Look for FU per capsule or daily serving, capsule type, soy or other allergen statements, vitamin K2 content, added enzymes or herbs, excipients, and directions for use. If you are unsure, ask a pharmacist to review the label.
Is nattokinase suitable for vegetarians, vegans or common allergies?
It depends on the product. Some nattokinase capsules may be plant based, while others may use gelatin. Because nattokinase is linked with fermented soy, people with soy allergy or sensitivity should check the label and seek advice.
What is nattokinase and what is it used for?
Nattokinase is an enzyme made during soybean fermentation into natto. It is used as a dietary supplement, most commonly by adults interested in circulation and cardiovascular wellness support.
What does nattokinase do for the body?
Nattokinase may influence fibrin-related pathways and has been studied for cardiovascular markers. The evidence is still developing, so we recommend treating it as a wellness supplement rather than a medical treatment.
Next steps
- Compare nattokinase supplements
- View nattokinase 2,000 FU 100 mg
- View Natto Serra
- Browse heart health support
- Compare vitamin K products