THE PROMISE
Maximum strength nattokinase. Patented, proven, vitamin K-free.
Nattokinase NSK-SD® is the world's most extensively studied nattokinase extract — with over million in safety and efficacy research behind it. Our formula delivers more than 20,000 FU per gram, with all Vitamin K removed for a safe, clean profile. Practitioner-trusted since 1999.
Heart Health
Nattokinase supports healthy blood clotting activity and cardiovascular function — helping the heart work efficiently every day.*
Blood Flow
Supports breakdown of fibrin in the bloodstream, promoting smooth, fluid circulation throughout the entire body.*
Blood Pressure
Research suggests nattokinase may support healthy blood pressure already within the normal range — without harsh stimulants.*
Vitamin K-Free
NSK-SD® is extracted using a patented process that removes all Vitamin K — providing fibrinolytic benefits with a clean, verified safety profile.
WHY IT WORKS
Cardiovascular Support
Fibrinolytic Activity
Nattokinase assists in the breakdown of fibrin — a protein involved in blood clot formation — helping maintain healthy, fluid circulation. NSK-SD® delivers over 20,000 FU per gram, far exceeding most competing nattokinase products.
Cardiovascular Support
By supporting healthy blood clotting activity, nattokinase contributes to overall cardiovascular function and helps maintain healthy blood viscosity and vascular tone for long-term heart wellness.*
Blood Pressure Balance
Research suggests nattokinase may help maintain healthy blood pressure already within the normal range — a natural complement to any cardiovascular wellness protocol.*
Vitamin K-Free Safety
NSK-SD® is processed using a patented extraction method that removes all traces of Vitamin K — providing fibrinolytic benefits while maintaining a cleaner safety profile for those with medication sensitivities.
Customer Reviews
Tried, tested,
truly loved.
Your Protocol
When to take it,
and why it matters
Nattokinase works cumulatively and is best taken with food. For maximum benefit, research recommends one serving at night before bed — when the body's natural cardiovascular maintenance occurs.
Morning
Take 1 capsule with your morning meal. Starting your day with nattokinase allows the enzyme to begin supporting fibrinolytic activity during your most active hours.
Why it works
NSK-SD® nattokinase begins supporting healthy circulation and blood flow from the first dose of the day.
Afternoon
A second capsule at lunch maintains steady enzyme levels throughout the day. Cardiovascular health is built through consistency — not single doses.
Why it works
Sustained fibrinolytic activity supports healthy blood flow and viscosity across your busiest hours.
Evening
For best results, take one serving at night before bed. The body performs much of its cardiovascular maintenance overnight — making this the most supported time to dose.
Why it works
Nattokinase supports the body's natural overnight fibrinolytic processes for cardiovascular recovery.
Suggested Use
Simple capsules. Clinically dosed.
Vegetarian HPMC capsules. Take with or without food as directed by your healthcare professional.
What's Inside
What's inside,
and why it matters.
Nattokinase NSK-SD®
NSK-SD® is a patented, vitamin K-free nattokinase derived from authentic fermented natto. It delivers over 20,000 fibrin units per gram — more than 200% the enzymatic activity of most nattokinase products on the market. Backed by over million in safety and efficacy research. Produced from Bacillus subtilis natto, the same bacterial fermentation process used in traditional Japanese natto for centuries.
Patented NSK-SD® strain · Vitamin K removed · >20,000 FU/g · Bacillus subtilis natto · Third-party tested · Non-GMO.
Japan · NSK-SD® Patented Extract
Vegetarian Capsule (HPMC)
Hydroxypropyl methylcellulose (HPMC) — a plant-derived capsule that is free from gelatin, gluten, soy proteins, and common allergens. Chosen for maximum purity and tolerability. The capsule protects the active enzyme and disintegrates predictably for reliable delivery to the small intestine.
HPMC vegetarian capsule · Gluten-free · Dairy-free · No gelatin · No artificial coatings or fillers.
Vegetarian HPMC Capsule · Allergen-Free
Dr. Devin Ryerson
Founder & Chief Curator · Est. 1999Why It Matters
Built by someone with
personal stakes in it.
Devin started Pure Prescriptions in 1999 after battling Hodgkin's Lymphoma and losing his father to leukemia. That experience made him the most stubborn kind of formulator — one who refuses to ship anything he wouldn't take himself.
Every ingredient here earned its place through clinical evidence, third-party testing, and that same personal lens — the five collagen types, the organic fruiting-body mushrooms, the co-factors. Nothing is decorative.
"Pure Prescriptions has always been more personal than corporate. Built by family. Still independent."
Our StoryYour Journey
What to expect
Nattokinase works cumulatively. Here’s what customers experience over time.
Week 1–2
Circulation & Warmth
Many users notice improved warmth in extremities and a sense of better circulation within the first two weeks of consistent use.
Fibrinolytic Activity Begins
Week 4
Energy & Clarity
Improved oxygen-carrying efficiency in the blood translates to better energy levels and mental clarity throughout the day.
Cardiovascular Efficiency
Week 8
Heart Health Markers
Consistent users often report improved cardiovascular markers at checkups. Blood pressure tends to stabilize within the healthy range.
NSK-SD® Cumulative Effect
Week 12
Full Protocol Benefit
At 12 weeks the cumulative fibrinolytic benefits of daily nattokinase use are well-established. This is where the long-term cardiovascular investment pays off.
Full Cardiovascular Support
Results are best with daily use · Most customers see full benefits by week 12
Results vary from person to person.
The Science Behind NSK-SD®
Discovered from fermented natto.
Patented. Proven. Safe.
The most studied form available.
NSK-SD® is the world’s most extensively researched nattokinase extract — with over $1 million invested in safety and efficacy studies. It delivers over 20,000 fibrinolytic units per gram, with all Vitamin K removed through a patented extraction process.
- — Patented NSK-SD® extract — >20,000 FU/g enzymatic activity
- — Vitamin K removed — cleaner safety profile for medication-sensitive individuals
- — G.R.A.S. (Generally Recognized As Safe) designation
- — Vegetarian HPMC capsules — no gelatin, no fillers, no artificial coatings
For the strongest nattokinase available — endorsed by Dr. Hiroyuki Sumi himself — see Cardiokinase® with HTNK-J®.
Cardiovascular Wellness
Have Questions?
Everything you need to know.
Honest answers — no marketing spin. If your question isn’t here, our team responds within one business day.
Nattokinase is an enzyme extracted from natto — a traditional Japanese fermented soybean food. It was discovered by Dr. Hiroyuki Sumi in the 1980s while researching fibrinolytic (clot-dissolving) enzymes in fermented foods. NSK-SD® is derived from authentic Bacillus subtilis natto fermentation.
NSK-SD® is a patented nattokinase extract that has undergone more than $1 million in safety and efficacy research. It delivers over 20,000 fibrinolytic units per gram — far exceeding most competing products — and has had all Vitamin K removed through a specialized extraction process. It carries G.R.A.S. (Generally Recognized As Safe) status.
Vitamin K naturally occurs in natto and can interfere with anticoagulant medications such as warfarin (Coumadin®). NSK-SD® uses a patented process to remove all traces of Vitamin K, providing a cleaner safety profile for individuals who are medication-sensitive.
As a dietary supplement, take 1 to 3 vegetarian capsules daily, or as directed by your healthcare practitioner. May be taken with or without food. For best results, consider taking one serving at night before bed when the body performs natural cardiovascular maintenance.
If you are taking anticoagulant medications such as warfarin, clopidogrel, or aspirin, please consult your physician before taking nattokinase. Nattokinase has fibrinolytic properties that may interact with anticoagulant therapy.
Cardiokinase® uses HTNK-J® — a newer, more potent nattokinase strain developed by Dr. Hiroyuki Sumi in collaboration with Pure Prescriptions, delivering 2,500 FU per softgel with the exclusive personal endorsement of Dr. Sumi. Nattokinase NSK-SD® is the same patented, vitamin K-free nattokinase used in clinical studies and is an excellent choice for most users at a lower price point.
Many users begin noticing improved circulation and cardiovascular comfort within 2–4 weeks of consistent daily use. Nattokinase works cumulatively — consistent daily use over 30–90 days typically yields the most meaningful results.
Doctor’s Protocol
How I’d build your cardiovascular foundation.
“Nattokinase addresses the fibrinolytic side of cardiovascular health. Paired with Omega-3 for arterial flexibility, CoQ10 for cardiac energy, and if needed upgraded to Cardiokinase® — you have a complete, layered cardiovascular protocol.”
In Order of Priority
4 Products · 1 Protocol
Cardiovascular · Fibrinolytic · Blood Flow
Nattokinase NSK-SD
Start here. Clinical-grade NSK-SD® nattokinase — the world's most researched fibrinolytic enzyme, with all Vitamin K removed and over $1 million in safety and efficacy research behind it.
HTNK-J® · Endorsed by Dr. Sumi
Cardiokinase®
The strongest nattokinase available — HTNK-J® strain personally endorsed by Dr. Hiroyuki Sumi, the discoverer of nattokinase. Maximum fibrinolytic potency for those requiring aggressive cardiovascular support.
VESIsorb® Enhanced Absorption
Premium Omega-3 Plus
Omega-3 fatty acids and nattokinase support cardiovascular health from two distinct, complementary pathways — blood viscosity and arterial wall integrity — for comprehensive heart protection.
Cellular Energy · Heart Support
Bioactive Coenzyme Q10
CoQ10 fuels cardiac muscle mitochondria — the energy substrate the heart needs to pump efficiently. Pairs synergistically with nattokinase's fibrinolytic support for complete cardiovascular coverage.
Add the full protocol — earn $25 store credit on your next order.
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