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Dietary supplement

NSK-SD Nattokinase 36 mg Ingredients & Drug Interactions

by Source Naturals

NSK-SD Nattokinase 36 mg label
See full label image
Softgel 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 NSK-SD Nattokinase 36 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

NSK-SD Nattokinase 36 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 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 NSK-SD Nattokinase 36 mg by Source Naturals

Ask about any prescription or over-the-counter medication and we check it for interactions with NSK-SD Nattokinase 36 mg by Source Naturals — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of NSK-SD Nattokinase 36 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 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 36 mg of nattokinase, a protein enzyme derived from fermented soybeans (natto). Nattokinase is included for its potential effects on blood flow and clotting.

The softgel also contains inactive ingredients: soybean oil, gelatin, glycerin, beeswax, glycerin fatty acid ester, and soybean lecithin. These are fillers and capsule materials that help deliver the active ingredient.

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: 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.

The evidence for nattokinase in our data is not established. We hold ratings for angina, atherosclerosis, cancer, cardiovascular disease, and chronic fatigue syndrome—all of them insufficient reliable evidence to rate.

That means the research so far doesn't give us a clear picture of whether it works for these conditions. If you're considering nattokinase for a specific health concern, talk with your pharmacist or doctor about what the broader research shows.

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 tolerated in the short term, but its blood-thinning effect means you need to be cautious if you have any bleeding risk. Rare cases of bleeding, including serious brain hemorrhage, have been reported—particularly when combined with aspirin or other blood thinners.

Nattokinase can cause allergic reactions in people sensitive to natto or its components. Symptoms typically appear within 2 hours and can range from throat and mouth tingling to anaphylaxis.

Safety data during pregnancy and breastfeeding are not adequate, so both are best avoided until you know more.

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 start nattokinase, double-check if you're taking any blood thinners or antiplatelet drugs (such as warfarin, dabigatran, apixaban, aspirin, or clopidogrel)—the bleeding risk is Moderate. Also flag any blood pressure medications (antihypertensives) with your pharmacist, since nattokinase may lower your pressure further.

Altogether, these interactions span 287 individual medications.

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 supplement is for people interested in blood flow support who aren't taking blood thinners, antiplatelet drugs, or blood pressure medications. If you take any of those, or if you have a bleeding disorder, check with your pharmacist first.

Pregnant or breastfeeding? Skip it for now.

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 Jan 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 NSK-SD Nattokinase 36 mg, straight from the product label.

Brand Source Naturals
Barcode (UPC) 021078017257
Net contents 90 Softgel(s)
Market status On market
Date entered into DSLD Jan 23, 2023
DSLD ID 273339
Product type Non-nutrient/non-botanical
Supplement form Softgel 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 NSK-SD Nattokinase 36 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 Softgel(s)
Maximum serving Sizes:
2 Softgel(s)
Servings per container
45
UPC/BARCODE
021078017257
IngredientAmount% DV
Nattokinase72 mg--

Other ingredients: Soybean Oil, Gelatin, Glycerin, Beeswax, Glycerin Fatty Acid Ester, Soybean Lecithin

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

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

Suggested/Recommended/Usage/Directions

Suggested Use: 1 to 2 softgels three times daily on an empty stomach with 8 ounces of water.

Storage

Store in a cool, dry place.

Precautions

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

Keep out of the reach of children.

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.

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.

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

NSK-SD Nattokinase 36 mg by Source Naturals label

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

NSK-SD Nattokinase 36 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 NSK-SD Nattokinase 36 mg by Source Naturals

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

Serving size1 Softgel(s) Dosage formSoftgel Capsule Servings per container45 Amounts shown are per serving.

Nattokinase

Interacts with
289 drugs
72 mg 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: Soybean Oil, Gelatin, Glycerin, Beeswax, Glycerin Fatty Acid Ester, Soybean Lecithin. These complete the product’s ingredient list but are not active constituents.

Interaction report

NSK-SD Nattokinase 36 mg by Source Naturals Drug Interactions

Want to check YOUR meds against NSK-SD Nattokinase 36 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 NSK-SD Nattokinase 36 mg interact with 289 drugs. Click any drug to see the details.

1 of the 1 ingredient in NSK-SD Nattokinase 36 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 NSK-SD Nattokinase 36 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 NSK-SD Nattokinase 36 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

NSK-SD Nattokinase 36 mg by Source Naturals: Common Questions

Does NSK-SD Nattokinase 36 mg by Source Naturals interact with any medications?
Yes. Based on its ingredients, NSK-SD Nattokinase 36 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?
NSK-SD Nattokinase 36 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?
No, not without talking to your pharmacist first. There's a documented case of serious brain bleeding when nattokinase was added to low-dose aspirin. Your pharmacist needs to assess your individual situation.
What's nattokinase, and where does it come from?
It's an enzyme from fermented soybeans (natto). Your body can't make it, and it's not found in foods other than fermented soy. This supplement delivers a concentrated dose.
Is nattokinase proven to work?
Not yet—at least not in the data we hold. The evidence for it in angina, heart disease, atherosclerosis, and other conditions is insufficient to say whether it works. More research is needed.
Can I take nattokinase while pregnant or breastfeeding?
No. There isn't enough safety data in pregnancy or while breastfeeding, so it's best to avoid it until you know more. Talk with your doctor if you're curious.
What if I'm allergic to soy?
Be very careful. Nattokinase comes from fermented soybeans, and allergic reactions—including severe ones—have been reported in people sensitive to natto. Speak with your pharmacist before trying it.

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

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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.

NSK-SD Nattokinase 36 mg label
Go deeper

The Full Monographs Behind NSK-SD Nattokinase 36 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

NSK-SD Nattokinase 36 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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