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Dietary supplement

Nattokinase 100 mg Ingredients & Drug Interactions

by NOW

Nattokinase 100 mg label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Nattokinase 100 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Nattokinase 100 mg is a dietary supplement by NOW with 1 active ingredient. Its ingredients are commonly taken for heart and circulatory health, blood clot prevention, high blood pressure.Based on those ingredients, 289 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Nattokinase. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Nattokinase 100 mg by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with Nattokinase 100 mg by NOW — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Nattokinase 100 mg by NOW

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: nattokinase, an enzyme derived from fermented soybeans. It's designed to support cardiovascular and circulatory health through its blood-thinning and fibrin-breaking (thrombolytic) effects.

The capsule also contains inactive ingredients — microcrystalline cellulose, hypromellose, stearic acid, and silicon dioxide — which are fillers and binders that help form and preserve the capsule.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Nattokinase's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: cardiovascular health and normal blood flow.
  • We looked for evidence on: Angina, Atherosclerosis, Cardiovascular disease (CVD), Hyperlipidemia, Hypertension, Peripheral arterial disease (PAD) — and 4 related terms.
  • The closest evidence on file: Nattokinase is rated "Insufficient Reliable Evidence To Rate" for Angina (Natural Medicines).
  • Also on file: Nattokinase is rated "Insufficient Reliable Evidence To Rate" for Atherosclerosis, Cardiovascular disease (CVD), Hyperlipidemia, Hypertension, and more.

The evidence for nattokinase's effectiveness isn't established in our data. The facts we hold don't rate it as proven for angina, atherosclerosis, cancer, cardiovascular disease, or chronic fatigue syndrome — all show insufficient reliable evidence.

That doesn't mean it doesn't work; it means the clinical research we have access to hasn't confirmed it yet.

The evidence, ingredient by ingredient Nattokinase

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Nattokinase is generally well tolerated in the short term, but its blood-thinning effect means caution if you have any bleeding risk — including a history of hemorrhage or a bleeding disorder. Rare cases of serious bleeding, including intracranial hemorrhage, have been reported.

Additionally, nattokinase may trigger hypersensitivity reactions in people sensitive to natto (fermented soybeans), with symptoms like throat swelling or anaphylaxis occurring within 2 hours of ingestion. The safety data advises against using nattokinase during pregnancy and while breastfeeding.

Side effects, ingredient by ingredient Nattokinase

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Nattokinase.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 289 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Check your exact medications if you take blood thinners or antiplatelet drugs (like aspirin, warfarin, apixaban, clopidogrel) — there's a Moderate risk of increased bleeding, including rare serious hemorrhage. Also double-check blood pressure medications, as nattokinase may lower blood pressure further.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Nattokinase may appeal to people looking to support heart and circulation health naturally, but it's not for you if you take blood thinners, antiplatelet drugs, or blood pressure medications without checking first — the bleeding and blood pressure risks are real. Steer clear during pregnancy and while nursing.

Talk to your pharmacist before starting, especially if you have a bleeding disorder or a family history of stroke.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated May 23, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Nattokinase 100 mg, straight from the product label.

Brand NOW
Barcode (UPC) 733739031419
Net contents 120 Veg Capsule(s)
Market status On market
Date entered into DSLD May 23, 2024
DSLD ID 313867
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Kosher, Women (not pregnant or lactating), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Nattokinase 100 mg by NOW, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Veg Capsule(s)
Maximum serving Sizes:
1 Veg Capsule(s)
Servings per container
120
UPC/BARCODE
733739031419
IngredientAmount% DV
Nattokinase100 mg--

Other ingredients: Microcrystalline Cellulose, Hypromellose, Stearic Acid, Silicon Dioxide

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Suggested Usage: Take 1 capsule 1 to 2 times daily on an empty stomach.

Formula

Nattokinase is an enzyme isolated from Natto, a traditional Japanese fermented soy food. Natto has been consumed for thousands of years for its numerous health promoting properties. More recently, both clinical and non-clinical studies have demonstrated that Nattokinase can help to promote heart and circulatory health by supporting normal blood clotting functions. NOW Nattokinase is derived from non-GMO soy and has 2,000 FUs (Fibrinolytic Units) per 100 mg serving.

Nattokinase 2,000 FUs of Activity

Triangle K (Kosher)

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Precautions

Caution: For adults only. Keep out of reach of children.

Do not use if pregnant or nursing, taking "blood thinning" medications (anticoagulants) (such as aspirin, warfarin, heparin), of if you have any ongoing bleeding/coagulation problems (including but not limited to: active ulcer, recent surgery/trauma, hemophilia).

Consult physician if you have a medical condition (including uncontrolled high blood pressure [equal to or higher than 200 mmHg/110 mmHg]).

Contains soy.

Not manufactured with wheat, gluten, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

Formulation

Cardiovascular Health Helps maintain normal blood flow

Vegetarian/Vegan

Made and quality tested in the USA with globally sourced ingredients.

Not manufactured with wheat, gluten, milk, egg, fish, shellfish or tree nut ingredients.

Contains no Vitamin K.

Natural color variation may occur in this product.

FDA Statement of Identity

A Dietary Supplement

Seals/Symbols

Triangle K (Kosher)

GMP Quality Assured

General Statements

General Health Family owned since 1968.

Storage

Store in a cool, dry place after opening.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Nattokinase 100 mg by NOW label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Nattokinase 100 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Nattokinase 100 mg by NOW

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Veg Capsule(s) Dosage formCapsule Servings per container120 Amounts shown are per serving.

Nattokinase

Interacts with
289 drugs
100 mg per serving Form: Natto Extract

Nattokinase is an enzyme from the fermented soybean food natto that may have mild blood-thinning and blood-flow effects. Some small studies hint at be...

Nattokinase monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Hypromellose, Stearic Acid, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Nattokinase 100 mg by NOW Drug Interactions

Want to check YOUR meds against Nattokinase 100 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
289Drugs
289 Moderate

Ingredients driving the most interactions

Nattokinase 289

Individual Drug Interactions

The ingredients in Nattokinase 100 mg interact with 289 drugs. Click any drug to see the details.

1 of the 1 ingredient in Nattokinase 100 mg interact with drugs. Each result below shows which ingredient is responsible. Nattokinase

Each ingredient & the kinds of drugs it affects

For each ingredient in Nattokinase 100 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Nattokinase2 drug types · 289 drugs

Anticoagulant/Antiplatelet Drugs

Nattokinase might increase the risk of bleeding when used with anticoagulant/antiplatelet drugs.
Nattokinase has thrombolytic and anticoagulant effects. There is a case report of intracranial hemorrhage in a patient who added nattokinase to aspirin therapy.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, nattokinase might increase the risk of hypotension when used with antihypertensive drugs.
Some clinical research suggests that nattokinase may reduce systolic and diastolic blood pressure.

Likelihood Possible Evidence D
Nattokinase full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Nattokinase 100 mg, from the product label.

NOW

See all NOW products
Name
NOW FOODS
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
nowfoods.com
Pharmacist Counseling Corner

Nattokinase 100 mg by NOW: Common Questions

Does Nattokinase 100 mg by NOW interact with any medications?
Yes. Based on its ingredients, Nattokinase 100 mg has a known interaction with 289 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Nattokinase 100 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take nattokinase if I'm on aspirin?
Not without talking to your pharmacist first. Nattokinase has blood-thinning effects, and combining it with aspirin raises the risk of bleeding. A case report documents intracranial hemorrhage in someone who did exactly that. Your pharmacist can help weigh the risks for your situation.
Is nattokinase safe during pregnancy?
No. The safety data advises against it during pregnancy. If you're pregnant or planning to become pregnant, avoid this product and talk with your doctor about safer options.
Can I take nattokinase while breastfeeding?
No. Safety is unknown while breastfeeding, so it's best avoided. If you're nursing and interested in nattokinase, discuss safer alternatives with your pharmacist.
What is nattokinase and where does it come from?
Nattokinase is an enzyme extracted from natto, a traditional Japanese food made from fermented soybeans. It works by thinning the blood and breaking down fibrin, a protein involved in blood clots.
Could nattokinase cause an allergic reaction?
Yes — rare but serious hypersensitivity reactions are possible, especially in people sensitive to natto. Symptoms like throat swelling or difficulty breathing can appear within 2 hours. If you have a known soy allergy, avoid this product.
Does nattokinase actually work for heart health?
We don't have reliable evidence proving it works for angina, atherosclerosis, cardiovascular disease, or other heart conditions. More research is needed before we can say whether it delivers on those claims.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Nattokinase 100 mg is safe with your meds?

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Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Nattokinase 100 mg label
Go deeper

The Full Monographs Behind Nattokinase 100 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Nattokinase

Interacts with 289 drugs

Nattokinase is an enzyme from the fermented soybean food natto that may have mild blood-thinning and blood-flow effects. Some small studies hint at benefits for blood pressure and circulatio...

Read the full Nattokinase monograph →
Sources

Sources & How We Checked

Nattokinase 100 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 9 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Nattokinase 9 references
  1. Suzuki Y, Kondo K, Matsumoto Y, et al. 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;73:1289-98.. PubMed
  2. Sumi H, Hamada H, Nakanishi K, Hiratani H. Enchancement of fibrinolytic activity in plasma by oral administration of nattokinase. Acta Haematol 1990;84:139-43.
  3. Chang, Y. Y., Liu, J. S., Lai, S. L., Wu, H. S., and Lan, M. Y. Cerebellar hemorrhage provoked by combined use of nattokinase and aspirin in a patient with cerebral microbleeds. Intern Med 2008;47(5):467-469. PubMed
  4. Kim, J. Y., Gum, S. N., Paik, J. K., Lim, H. H., Kim, K. C., Ogasawara, K., Inoue, K., Park, S., Jang, Y., and Lee, J. H. Effects of nattokinase on blood pressure: a randomized, controlled trial. Hypertens.Res 2008;31(8):1583-1588. PubMed
  5. <p>Maruyama M, Sumi H (eds): Effect of natto diet on blood pressure, in Basic and Clinical Aspects of Japanese Traditional Food Natto II. Japan Technology Transfer Association (JTTAS), 1998, pp 1–3.</p>
  6. Kurosawa Y, Nirengi S, Homma T, et al. A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles. Sci Rep 2015;5:11601. PubMed
  7. Ramachandran L, Aqeel A, Jafri A, Sidhu Y, Mohamed Djirdeh T. Nattokinase-associated hemoperitoneum in an elderly woman. Cureus 2021;13(12):e20074. PubMed
  8. Awatani-Yoshidome K, Hashimoto T, Satoh T. Anaphylaxis from nattokinase in a patient with fermented soybean (natto) allergy. Allergol Int 2022;71(1):153-4. PubMed
  9. Suzuki K, Nakamura M, Sato N, Futamura K, Matsunaga K, Yagami A. Nattokinase, a subtilisin family serine protease, is a novel allergen contained in the traditional Japanese fermented food natto. Allergol Int 2022.

See these in context on the Nattokinase monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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