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Dietary supplement

Nattokinase 2,000 FUs Ingredients & Drug Interactions

by Doctor's Best

Nattokinase 2,000 FUs label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Nattokinase 2,000 FUs 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 2,000 FUs is a dietary supplement by Doctor's Best 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 2,000 FUs by Doctor's Best

Ask about any prescription or over-the-counter medication and we check it for interactions with Nattokinase 2,000 FUs by Doctor's Best — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Nattokinase 2,000 FUs by Doctor's Best

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 Aug 27, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 1 active ingredient.

This product contains one active ingredient: nattokinase, a 2,000 FU (fibrinolytic units) enzyme derived from natto—a fermented soybean food. Nattokinase has blood-thinning and clot-dissolving effects in the body.

The capsule itself is filled with inactive ingredients (maltodextrin, hypromellose, and magnesium stearate), which are binders and fillers.

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 and circulatory health support.
  • We looked for evidence on: Atherosclerosis, Cardiovascular disease (CVD), Hypertension, Hyperlipidemia, Peripheral arterial disease (PAD), Venous insufficiency — and 4 related terms.
  • The closest evidence on file: Nattokinase is rated "Insufficient Reliable Evidence To Rate" for Atherosclerosis (Natural Medicines).
  • Also on file: Nattokinase is rated "Insufficient Reliable Evidence To Rate" for Cardiovascular disease (CVD), Hyperlipidemia, Hypertension, Peripheral arterial disease (PAD), and more.

We hold effectiveness data for nattokinase across several cardiovascular conditions—angina, atherosclerosis, and cardiovascular disease—but the evidence for all of them is insufficient to make a reliable rating. Its effectiveness for cancer and chronic fatigue syndrome is similarly unproven in the data we hold.

If you're considering nattokinase for any specific health goal, talk with your doctor about what the current science actually supports for your situation.

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 you need to be careful if you have any bleeding risk or take medications that thin your blood. Rarely, it has been linked to bleeding complications, including a serious case of brain hemorrhage when combined with aspirin.

There isn't enough safety data for pregnancy, so the evidence advises against use during pregnancy. Safety while breastfeeding is unknown, so it's best avoided then too.

Additionally, if you're allergic or sensitive to natto (fermented soybeans), nattokinase can trigger hypersensitivity reactions, ranging from throat or mouth swelling to, rarely, anaphylaxis—symptoms usually appear within two hours of taking it.

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.

Before you take this, double-check with your doctor or pharmacist if you're on a blood thinner or antiplatelet drug (like aspirin, warfarin, or clopidogrel)—nattokinase can increase bleeding risk. Also flag any blood-pressure medication you take, because nattokinase may lower blood pressure further.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

Nattokinase is a blood-thinning enzyme that may help support cardiovascular health, but the evidence for its specific uses isn't yet solid. If you take a blood thinner, antiplatelet drug, or blood-pressure medication, you'll need to check with your doctor or pharmacist before starting it—the interaction risk is real.

If you're pregnant, breastfeeding, or allergic to natto, skip this one. Talk with your doctor about whether it fits your needs and medications.

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 Feb 22, 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 2,000 FUs, straight from the product label.

Brand Doctor's Best
Barcode (UPC) 753950002531
Net contents 270 Veggie Cap(s)
Market status On market
Date entered into DSLD Feb 22, 2024
DSLD ID 302693
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), Women (not pregnant or lactating), Dairy 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 2,000 FUs by Doctor's Best, 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 Veggie Capsule(s)
Maximum serving Sizes:
1 Veggie Capsule(s)
Servings per container
270
UPC/BARCODE
753950002531
IngredientAmount% DV
Nattokinase0 NP--

Other ingredients: Maltodextrin, Hypromellose, Magnesium Stearate

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.
Formula

Nattokinase is an enzyme derived from "natto," a traditional fermented soy food popular in Japan. During the natto production process, non-GMO soybeans are boiled and fermented with friendly Bacillus subtilis bacteria producing nattokinase. Doctor's Best Nattokinase contains nattokinase enzyme with vitamin K2 removed. Nattokinase has been shown to support a healthy circulatory system by helping to maintain normal fibrinogen levels in blood.

Formulation

Doctor's Best Nattokinase contains nattokinase enzyme with Vitamin K2 removed.

Helps support a healthy circulatory system

Helps support cardiovascular and circulatory health

Non-GMO/Vegan

Non-GMO/Vegan

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.

Brand IP Statement(s)

Doctor's Best Science-Based Nutrition

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

Vegan

Precautions

Contains soy

Warning: Do not use this product if you are pregnant or nursing, are allergic to soy, or if you are taking blood-thinning medication, consult a physician before taking this product.

Warning: Do not use this product if you are pregnant or nursing, are allergic to soy, or if you are taking blood-thinning medication, consult a physician before taking this product.

Suggested/Recommended/Usage/Directions

Suggested adult use: Take 1 capsule daily between meals, or as recommended by a nutritionally informed physician.

Storage

Store in a cool dry place.

General Statements

FU - enzyme activity in fibrinolytic units

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

See for yourself

Nattokinase 2,000 FUs by Doctor's Best label

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

Nattokinase 2,000 FUs 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 2,000 FUs by Doctor's Best

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

Serving size1 Veggie Capsule(s) Dosage formCapsule Servings per container270 Amounts shown are per serving.

Nattokinase

Interacts with
289 drugs
0 NP per serving Form: Fibrinase

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: Maltodextrin, Hypromellose, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Nattokinase 2,000 FUs by Doctor's Best Drug Interactions

Want to check YOUR meds against Nattokinase 2,000 FUs?

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 2,000 FUs interact with 289 drugs. Click any drug to see the details.

1 of the 1 ingredient in Nattokinase 2,000 FUs 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 2,000 FUs 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 2,000 FUs, from the product label.

Doctor's Best

See all Doctor's Best products
Name
Doctor's Best, Inc.
City
Tustin
State
California
ZipCode
92780
Phone Number
(800) 777-2474
Web Address
www.drbvitamins.com
Pharmacist Counseling Corner

Nattokinase 2,000 FUs by Doctor's Best: Common Questions

Does Nattokinase 2,000 FUs by Doctor's Best interact with any medications?
Yes. Based on its ingredients, Nattokinase 2,000 FUs 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 2,000 FUs 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 checking first. Nattokinase thins the blood, and combining it with aspirin—even low-dose aspirin—raises your bleeding risk. There's a documented case of serious brain hemorrhage in someone who took nattokinase with aspirin. Talk to your doctor or pharmacist before mixing them.
What is nattokinase, and where does it come from?
Nattokinase is an enzyme made from natto, a traditional Japanese fermented soybean food. It works as a blood thinner and clot-dissolver in the body.
Can I take nattokinase during pregnancy or while breastfeeding?
No. There isn't enough safety data during pregnancy, so it's best avoided then. Safety while breastfeeding is also unknown, so it should be avoided then too. Talk with your doctor about any blood-support needs while pregnant or nursing.
Does nattokinase actually work for heart disease or stroke prevention?
The evidence we have doesn't yet support a reliable rating for nattokinase in heart disease, atherosclerosis, angina, or stroke prevention. If heart health is your goal, ask your doctor what treatments have solid proof behind them.
What if I'm allergic to soy or natto—can I take this?
No. Nattokinase is made from natto soybeans, and people sensitive to natto can have allergic reactions ranging from throat swelling to anaphylaxis, usually within two hours. Avoid it if you know you're allergic to natto or soy.
What are the side effects of nattokinase?
Short-term use is generally well tolerated. The main concern is bleeding risk, especially if you also take blood thinners or aspirin. Rarely, serious bleeding (including brain hemorrhage) has been reported. Allergic reactions are uncommon but can include throat or mouth swelling and, very rarely, anaphylaxis.

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

Not sure if Nattokinase 2,000 FUs is safe with your meds?

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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 2,000 FUs label
Go deeper

The Full Monographs Behind Nattokinase 2,000 FUs’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 2,000 FUs'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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