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Dietary supplement

Nattokinase 100 mg Ingredients & Drug Interactions

by Source Naturals

Nattokinase 100 mg label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 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 Source Naturals 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 NSK-SD. 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 Source Naturals

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

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HelloPharmacist Scorecard of Nattokinase 100 mg by Source Naturals

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

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 (NSK-SD), a protein enzyme extracted from natto, a fermented soy food. It's the sole component doing the work here.

The capsule also contains microcrystalline cellulose, gelatin, colloidal silicon dioxide, and magnesium stearate — these are inactive ingredients that help hold and deliver 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: systemic enzyme for healthy circulation.
  • We looked for evidence on: Angina, Atherosclerosis, Cardiovascular disease (CVD), Hyperlipidemia, Hypertension, Peripheral arterial disease (PAD) — and 3 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 we hold doesn't establish that nattokinase reliably works for any of the conditions commonly marketed for it — angina, atherosclerosis, cancer, cardiovascular disease, or chronic fatigue syndrome all carry a rating of insufficient reliable evidence. That doesn't mean it doesn't work; it means the research available to us hasn't proven 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 over the short term. The main safety concern is its blood-thinning effect — if you have a bleeding disorder or bleeding risk, you need to be cautious.

Rare reports link it to hemorrhage, including one case of brain bleeding in someone taking it with aspirin. The product should be avoided during pregnancy because there isn't enough safety data.

Safety while breastfeeding is also unknown, so it's best avoided then too. Some people can have a hypersensitivity reaction to nattokinase itself, with symptoms like throat or larynx swelling occurring within 2 hours of taking it — this is rare but can be serious.

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 with your doctor or pharmacist before using this if you take blood thinners or antiplatelet drugs (aspirin, warfarin, clopidogrel) — nattokinase can increase bleeding risk. Also flag it if you're on blood pressure medication, since 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.

This product is for someone interested in cardiovascular support who's aware the evidence isn't proven yet and has no bleeding risk or blood-pressure medications on board. If you take aspirin, any blood thinner like warfarin, or blood pressure pills, talk with your doctor or pharmacist before you start — the combination could be risky.

The same goes for anyone with a personal or family history of bleeding problems.

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, 2023.

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 Source Naturals
Barcode (UPC) 021078018858
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2023
DSLD ID 296100
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar 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 Source Naturals, 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:
1 Capsule(s)
Servings per container
60
UPC/BARCODE
021078018858
IngredientAmount% DV
NSK-SD100 mg--

Other ingredients: Microcrystalline Cellulose, Gelatin, Silicon Dioxide, Colloidal, 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

NSK-SD Whole-body systemic enzyme for healthy circulation

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.

FDA Statement of Identity

Dietary Supplement

Precautions

Contains soy.

Warning: Do not use if you have a blood coagulation or blood pressure disorder.

Consult your health care professional before taking this product if you are taking any drug that affects blood coagulation or blood pressure such as prescription vitamin K, heparin, warfarin (Coumadin), diuretics, ACE inhibitors, or beta blockers, or if you are pregnant, may become pregnant, or breastfeeding.

Do not use if either tamper-evident seal is broken or missing.

Keep out of the reach of children.

Suggested/Recommended/Usage/Directions

Suggested Use: 1 capsule three times daily on an empty stomach with 8 ounces of water.

Storage

Store in a cool, dry place.

Formulation

Contains no yeast, dairy, egg, gluten or wheat. Contains no sugar, salt, preservatives, or artificial color, flavor or fragrance.

Brand IP Statement(s)

NSK-SD is a trademark of Japan Bio Science Laboratories Co., Ltd.

Copyright SOURCE NATURALS, INC.

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.

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

See for yourself

Nattokinase 100 mg by Source Naturals 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 Source Naturals

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 container60 Amounts shown are per serving.

NSK-SD

Interacts with
289 drugs
100 mg per serving Form: Nattokinase

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...

NSK-SD monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Gelatin, Silicon Dioxide, Colloidal, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Nattokinase 100 mg by Source Naturals 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

NSK-SD 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. NSK-SD

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.

NSK-SD2 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
NSK-SD full monograph & interactions
The maker

Brand information

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

Source Naturals

Name
Source Naturals, Inc.
Street Address
P. O. Box 2118
City
Santa Cruz
State
CA
ZipCode
95062
Web Address
www.sourcenaturals.com
Pharmacist Counseling Corner

Nattokinase 100 mg by Source Naturals: Common Questions

Does Nattokinase 100 mg by Source Naturals 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 this with aspirin?
There's a documented case of someone who took nattokinase with low-dose aspirin and had a brain hemorrhage. Talk with your doctor or pharmacist before combining them — the bleeding risk is real.
Does nattokinase actually work?
We don't have reliable evidence that it works for the conditions it's marketed for — angina, heart disease, atherosclerosis, and the rest. Some research suggests it may lower blood pressure, but the evidence overall isn't established yet.
Is it safe if I have a bleeding disorder?
No. Nattokinase thins the blood, which makes it risky if you already have a bleeding tendency. Check with your doctor or pharmacist before taking it.
Can I take this while pregnant or breastfeeding?
No. There isn't enough safety data during pregnancy, so it's best avoided. Safety while breastfeeding is also unknown, so avoid it then too.
Are there side effects I should watch for?
Most people tolerate it well short-term. Rarely, people report bleeding or hemorrhage — watch for unusual bruising, bleeding gums, or nosebleeds. Some people can have an allergic reaction to natto, with throat or larynx swelling within 2 hours. Stop and seek help if that happens.

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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