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Nattokinase Supplement

$ 19.95

An enzyme derived from fermented soybeans, studied for its specific role in supporting healthy circulation and blood flow.* 4,000 FU per serving. Every batch tested. Third-party tests by ISO/IEC 17025 accredited labs. COAs published openly.
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Description

Nattokinase is a serine protease enzyme isolated from natto, a traditional Japanese fermented soybean food, first identified by Dr. Hiroyuki Sumi in 1980. Nattokinase is an enzyme studied for its role in supporting healthy circulation and cardiovascular wellness.* FU, fibrin units, measures enzyme activity.

This product provides 4,000 FU per serving, verified by third-party testing. Double Wood's formula delivers 4,000 FU (fibrin units) per 2-capsule serving, within the 2,000 to 10,800 FU range studied in published human research, with enzymatic activity verified every batch by an ISO/IEC 17025-accredited laboratory using a fibrin plate assay against reference standards.

For a more complete cardiovascular wellness routine, Nattokinase pairs well with D3K2.* One important timing note: take Nattokinase away from meals and D3K2 with a fat-containing meal, to respect how each ingredient is best absorbed.

Vegan, gluten-free, non-GMO.

Benefits
  • 4,000 FU per serving, within the 2,000 to 10,800 FU range studied in published human research, enzyme activity verified by ISO-accredited lab every batch
  • Supports healthy circulation and blood flow as part of a daily cardiovascular wellness routine*
  • Studied for its interaction with pathways involved in circulation support*
  • 120 capsules, a full two-month supply at the standard daily serving of 2 capsules
  • Vegan, Gluten-Free, Non-GMO, manufactured in a cGMP-certified U.S. facility from globally sourced ingredients

Directions & Dosage

Take 2 capsules (200mg, 4,000 FU) daily on an empty stomach, either 30 minutes before a meal or 2 hours after eating. Do not exceed the labeled dose. Discontinue use two weeks before any planned surgical procedure. If you take prescription anticoagulants, antiplatelet medications, or have a bleeding disorder, consult your healthcare provider before use.

The Science Behind Nattokinase (as Subtilisin NAT)

A distinct approach to circulation support. Rather than working through antioxidant pathways or vessel dilation like many cardiovascular supplements, nattokinase is studied for its role in supporting healthy circulation. This is why nattokinase has attracted research interest in the cardiovascular wellness category.*

Clinical research on cardiovascular markers. Clinical research has evaluated nattokinase in relation to cardiovascular markers over multi-week use. A randomized, double-blind, placebo-controlled trial by Kim et al. (2008) published in the Journal of Alternative and Complementary Medicine evaluated nattokinase supplementation in 92 participants over 8 weeks. A 2015 study by Jensen et al. published in Scientific Reports evaluated 2,000 FU daily over 26 weeks. Both studies used dose ranges consistent with Double Wood's 4,000 FU serving.*

Verified enzymatic activity matters. Most cardiovascular enzyme supplements list milligrams, not activity units. Milligram weight alone tells you nothing about how active or potent the enzyme actually is. FU (fibrin units) is the only meaningful measure of nattokinase potency. Double Wood verifies FU activity by fibrin plate assay against reference standards at an ISO/IEC 17025-accredited lab every batch, the same verification standard used in peer-reviewed research.

View Latest Test Results

Third-party tested for quality and purity

This production lot was tested for nattokinase activity, capsule quality, heavy metals, and microbial quality

Test Claim or Limit Result
Potency
Nattokinase NLT 3,600 FU 3,853.96 FU
Physical Testing
Capsule Weight 223-247 mg 235 mg
Disintegration Time NMT 30 minutes Passed
Heavy Metals
Arsenic (As) ICP <10 µg/serving 0.085 µg/serving
Cadmium (Cd) ICP <4.1 µg/serving 0.005 µg/serving
Lead (Pb) ICP <0.5 µg/serving 0.118 µg/serving
Mercury (Hg) ICP <0.3 µg/serving 0.000 µg/serving
Microbial Testing
Total Plate Count <10,000 CFU/g <190 CFU/g
Total Yeast & Mold Count <1,000 CFU/g <19 CFU/g
E. Coli Absent Absent
Salmonella spp. Absent Absent
Staphylococcus aureus Absent Absent

Lot: 2604805Manufactured: 04/2026

Lab: Brand Nutraceuticals, Inc.

View Certificate of Analysis (PDF)

See the original Certificate of Analysis for complete testing details, methods, and laboratory documentation.
View Certificate of Analysis View Third Party Test Results
Identity, potency, and contaminants verified per batch Identity, potency, and contaminants verified per batch
Manufactured in an FDA-registered cGMP facility Manufactured in an FDA-registered cGMP facility
Manufactured in the USA from Globally Sourced Materials Manufactured in the USA from Globally Sourced Materials

Benefits

  • CARDIOVASCULAR HEALTH - Nattokinase may help support a healthy circulatory system by lowering plasma levels of certain proteins that effect circulation
  • CIRCULATORY SUPPORT - Research suggests Nattokinase may help support cardiovascular health by promoting a healthy circulatory system
  • DERIVED FROM SOY (Japanese Natto) - Since Nattokinase is derived from fermented soybeans (Japanese Natto) there may be trace amounts of Soy in the product. Do not take if you are allergic to soy
  • TWO MONTH SUPPLY- Our Nattokinase supplement contains 60 servings of 200mg (4,000FU) which equals 120 Capsules (100mg 2,000 FU per capsule)
Benefits

Nattokinase (as Subtilisin NAT)

Nattokinase is a serine protease enzyme extracted from Bacillus subtilis natto, the bacterial culture responsible for fermenting soybeans into natto. It is an enzyme studied for its role in supporting healthy circulation.* Potency is measured in fibrin units (FU), the industry-standard measure of enzymatic activity. Double Wood's formula provides 2,000 FU per capsule and 4,000 FU per 2-capsule serving, verified by fibrin plate assay against reference enzyme standards in an ISO/IEC 17025-accredited laboratory every batch.

Nattokinase (as Subtilisin NAT)

What Customers Are Saying

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"Reputation of product and overall delivery and ordering experience has always been a good experience."

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"Always fast shipping and great selection no matter what you’re looking for."

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"Double Wood is always my go-to for supplements. Great, effective, clean products and always at a reasonable price."

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Supplement Facts

Pairs well with

Powerful alone, stronger together. Nattokinase Supplement delivers targeted support on its own, but combining it with complementary ingredients can help create a more holistic and balanced approach to wellness.

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    Liquid Vitamin B Complex: energize your daily routine with essential B vitamins for optimal well-being and vitality.

Frequently Asked Questions

What exactly is nattokinase and how does it work differently from other cardiovascular supplements?

Most cardiovascular supplements work upstream, through antioxidant activity, vessel relaxation, or lipid support. Nattokinase is studied for its role in supporting healthy circulation and cardiovascular wellness through a different pathway.* This is a targeted, mechanistically specific enzyme, which is why it has attracted consistent clinical research interest.

What does 4,000 FU mean and why does it matter more than milligrams?

Double Wood's formula delivers 4,000 FU per serving, verified by fibrin plate assay against reference enzyme standards every batch, falling within the 2,000 to 10,800 FU range studied in published human clinical research.

When is the best time to take nattokinase and why does it need to be on an empty stomach?

Take nattokinase on an empty stomach, either 30 minutes before a meal or 2 hours after eating. The reason is practical: digestive enzymes and food in the stomach can interfere with nattokinase's activity. Most people take it first thing in the morning for consistency.

What supplements pair well with Nattokinase?

D3K2 is a well-suited complementary addition for those building a cardiovascular wellness routine.* D3 and K2 support calcium metabolism for bone and vascular wellness, addressing a different dimension of cardiovascular health than nattokinase's circulation support. One important timing note: take Nattokinase on an empty stomach and D3K2 with a fat-containing meal. Keeping them separate by timing respects how each ingredient is best absorbed and gives you a cleaner, more intentional routine.

Is nattokinase safe to take if I'm on blood thinners or other medications?

This is the most important safety consideration for nattokinase, alongside its soy content. Because of its fibrinolytic properties, nattokinase should not be taken alongside prescription anticoagulants (warfarin, apixaban, rivaroxaban, dabigatran, edoxaban) or antiplatelet medications (clopidogrel, regular aspirin therapy) without consulting your healthcare provider first. The combination may have an additive effect on the fibrinolytic system. Those with bleeding disorders or scheduled for surgery within two weeks should also consult their provider before use. Contains soy; do not take if allergic.

Is Double Wood Nattokinase tested and what does the COA verify?

Every batch is independently tested by an ISO/IEC 17025-accredited laboratory. Testing covers enzymatic activity in FU by fibrin plate assay against reference standards, identity, four heavy metals by ICP-MS (arsenic, cadmium, lead, mercury, all verified below USP limits), and a full microbial panel including E. coli, Salmonella, and Staphylococcus aureus. The COA is publicly available on this page and includes the lot number so you can verify your specific bottle.

How long does it take to notice results and how should I approach consistent use?

Nattokinase builds with consistent daily use rather than producing an immediate noticeable effect. Published research has observed cardiovascular marker changes over 8 to 26-week periods of daily supplementation. The most honest positioning for nattokinase is circulatory maintenance — supporting the fibrinolytic system the body already has, consistently over time.* Daily use on an empty stomach at the same time each day is the most reliable approach.

Overall rating: 4.8055553 / 5 from 36 reviews.

AI Generated Review Summary

Summary topics

Review topics: [feeling, quality, price, order].

Review highlights

Reviews

"Just started with these… we’ll see how it goes. But i realky lije doublewood."

— Edwin (4/5)

Good quality, fingers crossed

"After researching what Natto is and why it's good for you, I chose to take this brand, due to their results by third party testing. Only time will tell if it has a positive affect on my cardio system."

— Jill B. (4/5)

"Came fast and so far going good. Will update rrview after a mint if i remember too"

— Suzannah (5/5)

"Working as expected"

— john (5/5)

Natto

"Good stuff"

— David P. (5/5)

Recommended for good health for

"Recommended for good health for the heart."

— Bernard K. (5/5)

Nattokinase

"Great product"

— Fred M. (5/5)

My doctor was amazed!

"I got the nattokinase, 4000FU I just wish it came in a larger dose as per the Chinese study ***pmc.ncbi.nlm.nih.***/articles/PMC9441630/ I upped my subscription to 3 bottles because I don't want to run out. I believe it's saving my life."

— Raymond W. (5/5)

My Cardiologist recommended this for

"My Cardiologist recommended this for my sticky blood."

— Mary C. (5/5)

Q&A

I don&#x27;t have high BP..it runs normal but I do have high chlorestal. My concern is the lowering of my bp...how much does this lower??
Thank you for reaching out with your question! For faster assistance with product-related inquiries, we recommend contacting our customer service team directly at hello@doublewoodsupplements.com. Our team will be happy to provide the information or support you need.

Nattokinase Supplement

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$ 19.95

Primary Benefit

Heart & Vessels

Other Benefits

Product Form

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