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Dietary supplement

Nattokinase NSK-SD Ingredients & Drug Interactions

by Klaire Labs

Nattokinase NSK-SD 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 NSK-SD 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 NSK-SD is a dietary supplement by Klaire Labs 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 NSK-SD by Klaire Labs

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

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HelloPharmacist Scorecard of Nattokinase NSK-SD by Klaire Labs

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.

Nattokinase NSK-SD contains one active ingredient: nattokinase, an enzyme derived from natto (fermented soybeans). It's a proteolytic enzyme — meaning it breaks down proteins — and the form here is standardized as NSK-SD.

The capsule also contains vegetarian capsule material, L-leucine, cellulose, and silicon dioxide as inactive ingredients.

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: Heart and circulatory health support.
  • 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 we hold does not establish nattokinase's effectiveness for angina, atherosclerosis, cancer, cardiovascular disease, or chronic fatigue syndrome — all are rated as having insufficient reliable evidence to rate. If you're considering it for one of these conditions, talk with your doctor about what the current research supports.

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, but its blood-thinning action means it warrants caution in anyone at risk of bleeding. Rare cases of bleeding and hemorrhage have been reported, including one involving brain bleeding when combined with aspirin.

Some people may have hypersensitivity reactions (including severe ones like anaphylaxis) if sensitive to natto or its proteins — symptoms can appear within 2 hours. The safety data advises against nattokinase during pregnancy and while breastfeeding, so those are times to skip 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 taking this product, double-check with your doctor or pharmacist if you take blood thinners or antiplatelet drugs (aspirin, warfarin, clopidogrel, and others) — nattokinase increases bleeding risk and has a case report of serious brain bleeding in this context. Also confirm it if you take blood pressure medications, 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.

Nattokinase may appeal to someone interested in natural fibrinolytic support, but it's not for anyone on blood thinners or blood pressure medications without first clearing it with their doctor or pharmacist. If you're pregnant, breastfeeding, or have a known natto allergy, avoid it.

Talk over your full medication list and health history with your healthcare provider before starting.

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 19, 2022.

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 NSK-SD, straight from the product label.

Brand Klaire Labs
Barcode (UPC) 828054001060
Net contents 60 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD May 19, 2022
DSLD ID 264948
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Gluten Free, 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 NSK-SD by Klaire Labs, 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
828054001060
IngredientAmount% DV
Nattokinase100 mg--

Other ingredients: Vegetarian Capsule, L-Leucine, Cellulose, 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.
FDA Statement of Identity

Enzyme Supplement

Precautions

Contains: Soy.

Caution: If you are pregnant, nursing, have a medical condition, or taking prescription drugs, consult your physician before using this product.

Keep out of reach of children.

Do not use if shrinkwrap is broken or missing.

Formulation

Free of the following common allergens: Milk/casein, eggs, fish, shellfish, tree nuts, peanuts, wheat, gluten, and yeast. Contains no artificial colors, flavors, or preservatives.

Produced under a strict quality management system in compliance with Good Manufacturing Practices (GMPs) and third-party quality certifications.

Suggested/Recommended/Usage/Directions

Suggested Use: 1 capsule, 2 times daily, 12 hours apart, with or between meals. Use is contraindicated in persons with history of bleeding tendency.

Formula

Fibrinolytic units or fibrin degradation units (FU) is a measure of enzyme activity. Nattokinase NSK-SD is standardized to contain 2,000 FU per capsule.

Brand IP Statement(s)

NSK-SD is a registered trademark of Japan Bio Science Laboratory.

SFI

Storage

Store in a cool, dry place (59 degrees F - 85 degrees F) away from direct light.

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

See for yourself

Nattokinase NSK-SD by Klaire Labs label

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

Nattokinase NSK-SD 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 NSK-SD by Klaire Labs

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.

Nattokinase

Interacts with
289 drugs
100 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: Vegetarian Capsule, L-Leucine, Cellulose, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Nattokinase NSK-SD by Klaire Labs Drug Interactions

Want to check YOUR meds against Nattokinase NSK-SD?

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 NSK-SD interact with 289 drugs. Click any drug to see the details.

1 of the 1 ingredient in Nattokinase NSK-SD 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 NSK-SD 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 NSK-SD, from the product label.

Klaire Labs

See all Klaire Labs products
Name
SFI USA
City
Reno
State
NV
ZipCode
89521
Web Address
Klaire.com
Pharmacist Counseling Corner

Nattokinase NSK-SD by Klaire Labs: Common Questions

Does Nattokinase NSK-SD by Klaire Labs interact with any medications?
Yes. Based on its ingredients, Nattokinase NSK-SD 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 NSK-SD 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 — there's a documented case of brain bleeding in someone who combined nattokinase with low-dose aspirin. Talk with your doctor or pharmacist before adding this product to any blood thinner or antiplatelet drug.
Is nattokinase safe during pregnancy?
The safety data advises against it during pregnancy. There isn't enough information to know it's safe, so it's best avoided. Talk with your doctor or pharmacist for personalized advice if you're thinking about it while pregnant.
Can I take it while breastfeeding?
The safety data advises against it while breastfeeding as well. There isn't enough information to know it's safe during lactation, so skip it and speak with your doctor or pharmacist for guidance.
What is nattokinase and where does it come from?
Nattokinase is an enzyme extracted from natto, which is fermented soybeans. It's a protein-breaking enzyme — a protease — that's been used in traditional Japanese cuisine for centuries.
Can someone with a natto allergy take this?
No. People sensitive to natto can have allergic reactions to nattokinase, including severe ones like anaphylaxis, with symptoms appearing within 2 hours of taking it. If you have a natto allergy, avoid this product.
Does nattokinase work for heart disease or high blood pressure?
The evidence we hold on file does not establish that nattokinase works for cardiovascular disease — it's rated as insufficient reliable evidence to rate. If you're considering it for a heart or blood pressure condition, talk with your doctor about what research supports its use.

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

Not sure if Nattokinase NSK-SD 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 NSK-SD label
Go deeper

The Full Monographs Behind Nattokinase NSK-SD’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 NSK-SD'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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