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Dietary supplement

Best Nattokinase Ingredients & Drug Interactions

by Doctor's Best

Best Nattokinase 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 Best Nattokinase 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

Best Nattokinase 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 Best Nattokinase by Doctor's Best

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

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HelloPharmacist Scorecard of Best Nattokinase 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 Jul 16, 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.

Best Nattokinase is a single-ingredient supplement containing nattokinase, an enzyme derived from fermented soybeans (natto). The capsule also contains inactive ingredients: modified cellulose, maltodextrin, and magnesium stearate.

Does it work?

Couldn't assess
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 assessable

This is a single-ingredient Nattokinase product and its label doesn't state a use — see Nattokinase's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence for nattokinase isn't established yet. The data we hold shows insufficient reliable evidence to rate it for angina, atherosclerosis, cancer, cardiovascular disease, or chronic fatigue syndrome.

If you're considering it for any of these conditions, talk with your doctor about whether the current evidence supports its use.

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 effects mean it isn't right for people at risk of bleeding. Rare cases of bleeding — including serious brain hemorrhage — have been reported, especially when combined with aspirin or other blood thinners.

There's also a small risk of allergic reactions in people sensitive to natto or its components; symptoms can develop within 2 hours of taking it. The safety data advises against nattokinase during pregnancy and breastfeeding.

There isn't enough information to know whether it's safe while breastfeeding, so it's best avoided during that time.

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 taking Best Nattokinase, check with your doctor or pharmacist if you're on blood thinners or antiplatelet drugs (such as warfarin, aspirin, or clopidogrel) — nattokinase raises bleeding risk. Also double-check if you take blood pressure medications, since nattokinase may lower pressure further.

If you have any bleeding disorder or are undergoing surgery, clear it first.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Nattokinase may appeal to people interested in cardiovascular support, but the evidence for specific conditions isn't yet established. If you take blood thinners, antiplatelet drugs, or blood pressure medications, this product isn't suitable without your doctor's approval — the risk of bleeding or low blood pressure is real.

Talk with your doctor or pharmacist before starting it, especially if you're on any blood-related or heart 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 Aug 23, 2013.

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 Best Nattokinase, straight from the product label.

Brand Doctor's Best
Barcode (UPC) 753950001350
Net contents 30 Veggie Cap(s)
Market status On market
Date entered into DSLD Aug 23, 2013
DSLD ID 24619
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)
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 Best Nattokinase 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 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
30
UPC/BARCODE
753950001350
IngredientAmount% DV
Nattokinase2000 FU--

Other ingredients: Modified Cellulose, Maltodextrin, 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

Contains Soy

Best Nattokinase contains nattokinase enzyme with Vitamin K2 removed.

2,000 FUs PER VEGGIE CAP

Precautions

Contains Soy

Do not use this product if you are pregnant or nursing, are allergic to soy, or if you have a blood coagulation disorder. If you are taking an anticoagulant (bloodthinning medication) or vitamin K, consult a physician before taking this product.

Do not use this product if you are pregnant or nursing, are allergic to soy, or if you have a blood coagulation disorder.

General Statements

Nattokinase is an enzyme derived from "natto," a traditional fermented soy food popular in Japan. During the natto production process friendly Bacillus subtilis bacteria ferment boiled, non-GMO soybeans, producing nattokinase.

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CONTAINS NOTHING OTHER THAN LISTED INGREDIENTS

Formulation

Best Nattokinase contains nattokinase enzyme with Vitamin K2 removed.

General

R 06/13

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)

Science-Based Nutrition(TM)

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

Vegan(TM)

Suggested/Recommended/Usage/Directions

Suggested Adult Use: Take 1 - 2 capsules daily, between meals.

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

See for yourself

Best Nattokinase by Doctor's Best label

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

Best Nattokinase 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 Best Nattokinase by Doctor's Best

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.

Nattokinase

Interacts with
289 drugs
2000 FU per serving

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

Interaction report

Best Nattokinase by Doctor's Best Drug Interactions

Want to check YOUR meds against Best Nattokinase?

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 Best Nattokinase interact with 289 drugs. Click any drug to see the details.

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

Each ingredient & the kinds of drugs it affects

For each ingredient in Best Nattokinase 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 Best Nattokinase, from the product label.

Doctor's Best

See all Doctor's Best products
Name
Doctor's Best, Inc.
City
San Clemente
State
CA
ZipCode
92673
Phone Number
(800) 777-2474
Web Address
www.drbvitamins.com
Pharmacist Counseling Corner

Best Nattokinase by Doctor's Best: Common Questions

Does Best Nattokinase by Doctor's Best interact with any medications?
Yes. Based on its ingredients, Best Nattokinase 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?
Best Nattokinase 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.
Who should avoid this product?
Anyone on blood thinners, antiplatelet drugs like aspirin, or blood pressure medications should not take nattokinase without their doctor's approval. It's also best avoided during pregnancy and breastfeeding, and in people with a history of bleeding disorders or sensitivity to natto.
Can this cause an allergic reaction?
Yes. People sensitive to natto can have hypersensitivity reactions to nattokinase or related compounds in the product. Symptoms like throat or larynx swelling can start within 2 hours of taking it. If you have a known natto allergy, don't take this product.
What is nattokinase?
Nattokinase is an enzyme from fermented soybeans (natto), a traditional Japanese food. It has blood-thinning properties, which is why it interacts with certain medications and carries a bleeding risk.
Does this product actually work for cardiovascular health?
The evidence isn't established yet. We don't have reliable data to rate nattokinase for heart disease, atherosclerosis, angina, or other conditions it's sometimes marketed for. Talk with your doctor about whether it's right for you.
What's in the capsule besides nattokinase?
The capsule also contains modified cellulose, maltodextrin, and magnesium stearate — these are inactive ingredients that help form and stabilize the capsule.

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

Not sure if Best Nattokinase 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.

Best Nattokinase label
Go deeper

The Full Monographs Behind Best Nattokinase’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

Best Nattokinase'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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