Best 10 Nattokinase Supplements In 2025

Nattokinase supplements contain a fermented soybean-derived natto compound, which is associated with some cardiovascular benefits. The natto content in these formulations may help dissolve blood clots, improve blood circulation, and decrease elevated blood pressure.

The nattokinase supplements are available in various strengths, which are measured in fibrinolytic units (FU). Multiple brands provide nattokinase supplements, but not all are created equal. Some brands may provide high natto potency and clean ingredients, while others may fall short on quality or testing.

In this article, we have curated a list of the 10 best nattokinase supplements available. We ranked these nattokinase formulations after a careful evaluation of factors like their brand reputation, pricing, and refund policies. The article also discusses some potential side effects associated with Nattokinase supplementation.

10 Best Nattokinase Supplements

1. Pure Encapsulations – NSK-SD

   

   Pure Encapsulations NSK-SD may support cardiovascular health and healthy blood circulation. As per the official site, one capsule provides 100 mg of NSK-SD® nattokinase, featuring 2,000 fibrinolytic units of nattokinase from soy.

   NSK-SD is a patented form of nattokinase that may support your body’s natural fibrinolytic system. It could gently break down excess fibrin in your blood to help minimize the risk of unwanted blood clots, which may otherwise cause poor blood circulation.

   The makers suggest taking one Pure Encapsulations NSK-SD capsule twice daily, preferably 12 hours apart, and either with or between meals. Pure Encapsulations also claims that its NSK-SD formulation is free from unnecessary allergens, such as GMOs, tree nuts, gluten, dairy, eggs, etc.
   

   Pros

   • Could help lower blood pressure by reducing cardiac strain.
   • May enhance blood circulation in peripheral arteries.
   • Comes with options to purchase bottles with 60 and 120 capsules.
   • Offers a non-GMO and vegan-friendly formula.

   Cons

   • May trigger allergic reactions, particularly in cases of soy sensitivity.
   • Could lead to dizziness or headaches.

2. Luma Nutrition – Nattokinase Vascular Cleanser

   

   According to the official site, Luma Nutrition’s Nattokinase Vascular Cleanser may help support circulatory and vascular health. One serving (two capsules) offers 200 mg of nattokinase, equivalent to 4000 FU. The makers state that Nattokinase Vascular Cleanser could help lower elevated blood pressure and minimize the risk of blood clot formation.

   Nattokinase may help improve blood lipid levels by influencing vital pathways involved in fat metabolism and circulation. It may help support notable reductions in total cholesterol, LDL (bad) cholesterol, and triglyceride levels. Such effects might help lower the risk of heart disease and cardiovascular issues.

   Luma Nutrition claims that its Nattokinase Vascular Cleanser formulation is made in GMP-certified and FDA-compliant facilities, which also undergo third-party testing by independent labs. Such certifications may indicate that the formulation undergoes regular checks for purity, safety, and quality.
   

   Pros

   • Could help support gut microbiome balance and digestion.
   • Might reduce inflammatory markers in the brain, thereby supporting cognitive health.
   • Could help shrink nasal polyps and thin mucus, aiding sinus health.
   • Offers a 90-day money-back guarantee on purchases.

   Cons

   • May dislodge blood clots, potentially increasing the risk of a stroke.
   • Not safe for use during pregnancy or lactation.

3. Xymogen – Nattokinase Capsules

   

   According to the official site, one Xymogen Nattokinase capsule features 100 mg (2,000 FU) of nattokinase. The formulation also comes in two different serving sizes, with 60 and 120 capsules per bottle.

   Nattokinase may help break down angiotensin-converting enzyme (ACE), which helps produce angiotensin II, a compound that causes blood vessels to tighten. It could help suppress ACE activity, which can make it easier for blood to flow and decrease pressure inside the vessels.

   The makers suggest taking 1–2 Xymogen Nattokinase capsule(s) daily, preferably taken at least 30 minutes before or two hours after a meal. However, Xymogen Nattokinase must be avoided if you have bleeding issues or are consuming blood thinners (such as warfarin or heparin).
   

   Pros

   • May help reduce arterial plaque buildup, providing an anti-atherosclerotic effect.
   • Could help lower LDL (bad) cholesterol and triglycerides, thereby supporting heart health.
   • Is free from common allergens, such as yeast, dairy, sesame, gluten, and egg.

   Cons

   • May interact with antihypertensive drugs, triggering dizziness or hypotension.
   • Could trigger side effects like bloating, stomach cramps, or diarrhea.

4. Designs for Health – Natto-Serrazime

   

   Natto-Serrazime by Designs for Health pairs Nattozimes® (derived from Aspergillus oryzae) and Serrazimes® (derived from Aspergillus melleus), two potent proteolytic enzymes that aim to support circulatory health. As per the official site, one capsule provides 129 mg of Nattozimes® (4,516 FU) and 33 mg of Serrazimes® (20,000 units of enzymatic activity).

   Serrazimes® could modulate inflammatory pathways, helping to lower tissue swelling and improve microcirculation, especially in capillaries and smaller blood vessels. Nattozimes® could improve blood fluidity and minimize fibrin build-up in blood vessels, which might help the heart pump blood more efficiently and support healthy blood pressure levels.

   These proteolytic enzymes could also help your body break down cellular debris, damaged proteins, and unwanted tissue byproducts. Such effects may support healthy blood circulation, joint comfort, and a balanced inflammatory response.
   

   Pros

   • Could help support joint health and reduce vascular inflammation.
   • Requires a convenient daily dose of one capsule.
   • Provides 120 capsules per bottle, potentially lasting a 4-month supply.

   Cons

   • May trigger potential allergic reactions like hives, itching, or swelling in the throat.
   • Variations in results and effectiveness.

5. Doctors Best – Nattokinase Veggie Caps

   

   According to the official site, one capsule of Doctor’s Best Nattokinase features 2,000 FU of nattokinase. The makers state that Doctor’s Best Nattokinase contains nattokinase with no vitamin K2 content, making the formulation potentially compatible for use alongside blood-thinning medications.

   Nattokinase may support the breakdown of fibrin, a protein involved in blood clot formation. It could also help support a healthy blood flow, reduce the risk of abnormal clotting, and support vascular integrity. As per the official site, one bottle of Doctor’s Best Nattokinase formulation costs $14.99 as part of a one-time purchase.
   

   Pros

   • Could help support healthy fibrinogen levels in blood.
   • Removes vitamin K2 content to help minimize the risk of interactions with blood thinners.
   • Offers a 60-day refund policy on purchases.

   Cons

   • Not compatible for users who have soy sensitivity or allergies.
   • May trigger side effects like dyspnea or chest pain.

6. Enzyme Science – Nattokinase Pro™

   

   As per the official site, Nattokinase Pro by Enzyme Science is formulated with 4,000 FU of nattokinase (featuring the patented NSK-SD®) per capsule. NSK-SD® may help reduce blood viscosity by promoting the breakdown of circulating proteins and lowering the risk of unnecessary clot formation. Such effects may improve circulation and reduce strain on the heart.

   Nattokinase Pro also comprises a mix of digestive support enzymes (Thera-blend®), including protease, amylase, cellulase, glucoamylase, and lipase. These enzymes may further support fibrin breakdown, digestive function, and systemic health.

   The Enzyme Science Nattokinase Pro formulation also contains ingredients like bromelain, calcium, and magnesium. Bromelain may support cardiovascular health by reducing inflammation in the blood vessels, which might lower the risk of atherosclerosis (plaque buildup).

   Calcium is essential for blood vessel contraction and relaxation. It could also help support a healthy heart rhythm and promote muscle function. Research suggests that magnesium supports the heart’s electrical activity, which may help stabilize heart rhythm and lower the likelihood of arrhythmias.
   

   Pros

   • Contains the patented NSK-SD®, which may offer better potency and standardization than standard nattokinase.
   • Opting for a subscription saves an extra 10% on the retail price.
   • Provides a Kosher and gluten-free formula, aligning with multiple dietary restrictions.

   Cons

   • The three-capsules-per-day dose may be inconvenient for some users.
   • Lacks long-term safety data for chronic use.

7. DaVinci Laboratories – Nattokinase Plus

   

   DaVinci Labs’ Nattokinase Plus could help support healthy blood circulation and vascular function. According to the official site, one serving (two capsules) contains 150 mg (20,000 Fu/g) of Natto NSP-2™, 150 mg of serratiopeptidase, and 200 mg of rutin.

   Serratiopeptidase in DaVinci Labs’ Nattokinase Plus is a proteolytic enzyme that may help break down non-living tissue, including scar tissue, dead cells, and inflammatory proteins. These effects might help reduce vascular inflammation and improve arterial elasticity, alongside promoting healthy blood circulation.

   Rutin is a natural flavonoid present in the DaVinci Labs’ Nattokinase Plus formula that has potent antioxidant and anti-inflammatory effects. It may help strengthen the structural integrity of your blood capillaries and veins, thereby minimizing the risk of bruising, spider veins, and varicose veins.

   The makers suggest taking 2 Nattokinase Plus capsules daily, preferably between meals to support vascular health. One jar of DaVinci Labs Nattokinase Plus contains 60 capsules and is available for $45.22 as part of a one-time purchase.
   

   Pros

   • Delivers high enzyme activity with 20,000 fibrin units (FU) per gram of Nattokinase.
   • The inclusion of rutin may help combat free radicals and support capillary strength.
   • Offers flexibility in subscriptions by offering delivery intervals of 30, 45, 60, and 90 days.

   Cons

   • Some consumers share concerns over inconsistent capsule filling.
   • Might potentially cause a sudden drop in blood pressure levels.

8. Double Wood Supplements – Nattokinase

   

   Double Wood Supplements Nattokinase provides 120 capsules per jar, which typically last a two-month supply when taken in the recommended dose of 2 capsules per day. As per the official site, each two-capsule serving offers 200 mg of nattokinase (4,000 fibrinolytic units).

   Nattokinase has fibrinolytic properties that may help lower plasma levels of proteins that cause blood clotting and poor circulation, such as fibrin, fibrinogen, and plasminogen activator inhibitor-1. Such effects might help improve circulation and decrease the risk of clot-related issues.
   

   Pros

   • Comes in double and triple packs to support consistent use.
   • Made in GMP-certified labs and undergoes third-party testing to check for quality and safety.
   • It is free from banned substances, animal byproducts, and unnecessary fillers.

   Cons

   • Might cause an increased risk of bleeding, especially when paired with anticoagulants.
   • Could trigger side effects like lightheadedness, stomach upset, or gas.

9. Deal Supplement – Nattokinase

   

   As per the official site, Nattokinase by Deal Supplement aims to support heart health, blood circulation, and digestive function. Each 2-capsule serving provides 200 mg of nattokinase (4,000 FU), 50 mg of bromelain (2,400 GDU), 2.5 mg of black pepper extract, and 50 mg of turmeric root extract.

   Bromelain in Nattokinase by Deal Supplement may help reduce platelet aggregation and break down fibrin, a protein involved in blood clot formation. Chronic inflammation may trigger vascular stiffness and plaque buildup in arteries. The inclusion of curcumin may help reduce markers of vascular inflammation like CRP (C-reactive protein) and decrease oxidative stress, all of which may support vascular health and overall circulation.
   

   Pros

   • Contains 240 veggie capsules per bottle, providing a long-lasting supply.
   • Includes curcumin extract for added antioxidant and anti-inflammatory benefits.
   • May help support heart health and digestive function.

   Cons

   • Even minor injuries may result in bruising due to nattokinase’s blood-thinning effects.
   • Could trigger mild to severe allergic reactions, including anaphylaxis.

10. NatureBell – Nattokinase 8000 FU

    

    According to the official site, every 3-capsule serving of Naturebell’s Nattokinase formula features 400 mg of nattokinase (equivalent to 8,000 FU). The high nattokinase concentration may help support healthy blood flow, reduce excess fibrin buildup, and contribute to circulatory health.

    Each bottle of Naturebell Nattokinase supplement contains 240 vegetarian capsules, providing around 80 servings at the recommended three-capsule daily dose. The makers state that Naturebell Nattokinase offers a non-GMO formula, which remains free of common allergens like wheat, eggs, preservatives, fish, and gluten.
    

    Pros

    • Could help maintain blood vessel structure through its fibrinolytic effects.
    • Rigorously third-party lab tested and provides Certificate of Analysis (COAs) upon request.
    • Comes in a UV-protected, double-sealed amber bottle to preserve freshness.

    Cons

    • Some consumers did not observe any noticeable benefits despite consistent use.
    • May trigger side effects like nausea, stomachache, or vomiting.

What Are Nattokinase Supplements?

Nattokinase supplements contain concentrated forms of natto, which is a traditional Japanese food made by fermenting soybeans with a specific bacterium called Bacillus subtilis. During fermentation, the bacteria produce the enzyme nattokinase, which is then extracted and used in supplement forms such as capsules, tablets, or powders.

Nattokinase may help break down fibrin, which is a protein involved in blood clotting. Such a mechanism might help improve blood circulation and lower the possibility of developing a blood clot.

In a randomized, double‑blind, placebo‑controlled trial, 86 adults with pre‑hypertension or stage‑1 hypertension took 2,000 FU of nattokinase daily for 8 weeks. They observed average drops of 5.55 mmHg in systolic and 2.84 mmHg in diastolic blood pressure. These findings may suggest that nattokinase may help support healthy blood pressure levels.

Side Effects of Nattokinase Supplements

1. Excess Bleeding

   Nattokinase supplements cause the fibrin breakdown that is responsible for blood clotting. In some situations, this action may disrupt your body’s natural ability to stop bleeding, causing excessive blood thinning. It may raise your risk of internal bleeding, prolonged bruising, or even hemorrhagic events.

   Excess bleeding risk may become more pronounced if you take nattokinase formulations alongside blood thinners, such as warfarin, aspirin, or NSAIDs (e.g., ibuprofen). As nattokinase supplements directly interfere with blood clot formation by degrading the fibrin matrix, even minor injuries might lead to significant blood loss.

2. Shortness of Breath

   Shortness of breath can be a serious adverse effect of nattokinase formulations, especially when taken without medical supervision. Unlike prescription anticoagulants, nattokinase supplements have inconsistent potency, lack standardized dosing, and are not monitored through reputable lab tests. These factors could make their blood-thinning effects unpredictable, increasing the risk of either too much or too little clot breakdown.

   When clot formation isn’t properly managed, you may face the risk of a thromboembolic event. Sometimes, a blood clot may travel to the lungs, causing a pulmonary embolism. It is a condition marked by symptoms like sudden shortness of breath, sharp chest pain, rapid heartbeat, or lightheadedness.

3. Potential For Allergic Reactions

   Nattokinase supplements may trigger concerning allergic reactions, especially if you’re allergic to natto (the fermented soy compound in nattokinase). Taking nattokinase formulations in such cases may trigger allergic reactions, like hives, swelling of the throat, low blood pressure, nausea, and vomiting.

   Your immune system could mistakenly identify nattokinase as a harmful substance and react by releasing large amounts of histamine and other chemicals. Such effects may cause blood vessels to dilate, tissues to swell, and airways to tighten, leading to the above-mentioned allergic symptoms. What’s more concerning is that even if you’re not allergic to soy or poly-γ-glutamic acid (another compound in natto), nattokinase alone may still trigger a severe reaction.

How Did We Evaluate The Best Nattokinase Supplements?

1. Price And Value

   To evaluate the overall value for money, we closely examined the cost per capsule with the quantity provided for these nattokinase formulations.

   Deal Supplement’s Nattokinase offers a strong value, as it provides one bottle (240 vegetarian capsules) for $30.95. It is followed closely by Naturebell Nattokinase Supplement, which offers one bottle (240 count) for $31.95.

   Meanwhile, one bottle of Doctor’s Best – Nattokinase Veggie Caps provides 90 capsules per container for a total cost of $14.99. Similarly, Double Wood Supplements – Nattokinase offers a balance between price and affordability by offering one jar (120 capsules) for $19.95.

   In the mid-range category, Luma Nutrition’s Nattokinase Vascular Cleanser provides one jar (60 capsule count) for $29.99, equating to a cost of $0.50 per capsule. It is followed by Designs For Health – Natto-Serrazime™, which offers one jar (120 capsule count) for $66.25, equating to a cost of around $0.55 per capsule. These options may provide a balance between affordability and branding.

   Slightly higher on the pricing scale was DaVinci Laboratories – Nattokinase Plus, which provides one bottle (60 capsules) for a price of $45.22. One bottle of Enzyme Science – Nattokinase Pro™ offers 60 capsules and is priced at $46.99. While not the most economical, these brands are recognized for their clinical-grade formulations and may be helpful if you are seeking therapeutic-grade enzyme support.

   Xymogen’s Nattokinase Capsules offer a premium price by providing one bottle (60 capsules) for $48.99. However, Pure Encapsulations – NSK-SD is the most expensive nattokinase formulation on the list. It offers one bottle (60 capsules) for a price of $78.60.

2. Brand Credibility

   When assessing brand credibility, we considered each brand’s ratings/presence on third-party review platforms like the Better Business Bureau (BBB) and Trustpilot.

   Double Wood Supplements maintains an “A+” rating on the Better Business Bureau (BBB) website. It also holds a 3.5 out of 5 rating on Trustpilot based on 155+ reviews. Meanwhile, Xymogen is not a BBB Accredited Business but holds an “A+” rating on the BBB platform. However, Xymogen has an unclaimed Trustpilot profile.

   Similarly, Designs for Health also r eceived an “A+” rating on BBB, although it too has an unclaimed profile on Trustpilot. The Pure Encapsulations brand does not have a claimed Trustpilot profile but has an “A-” BBB rating, possibly due to complaints filed against it on BBB.

   Other brands such as Doctor’s Best, Enzyme Science, DaVinci Laboratories, Deal Supplement, Luma Nutrition, and Naturebell have a low brand reputation. All of these brands lack presence on the BBB platform and have either unclaimed or nonexistent profiles on Trustpilot. Such limited transparency is the reason why we ranked these brands lower in the evaluation.

3. Returns and Refund Policy

   In evaluating the best Nattokinase supplements, we assessed the flexibility and transparency of each brand’s returns and refund policy. A longer refund window often reflects confidence in product quality and enhances customer trust.

   Luma Nutrition offers a generous 90-day money-back guarantee, although it requires the return of all bottles (opened or unopened). Deal Supplement and Naturebell both offer a 60-day money-back guarantee specifically for issues related to quality or health concerns. However, both these brands do not exclude return shipping charges from refunds.

   Similarly, Doctor’s Best provides a 60-day return period, allowing you to request refunds directly via their support team. While their terms are relatively flexible, the absence of clear guidelines on opened or used items makes the policy slightly ambiguous.

   Enzyme Science offers a straightforward 45-day return window, although the brand reserves the right to request product returns at your expense. Double Wood Supplements offers a 30-day refund policy but only on the first bottle (unopened) from any order, including multipacks. DaVinci Laboratories also allows returns within 30 days but only for unopened products, and returns beyond that are subject to around 20% restocking fee.

   Designs For Health and Pure Encapsulations impose more restrictive return policies. Both brands accept returns within 30 days for unopened items but charge a processing or restocking fee, which is 20% for Designs For Health and 15% for Pure Encapsulations.

   However, Xymogen has the most stringent refund policy among all the brands. It disallows returns altogether except in rare cases, such as damaged or incorrect items, with a narrow 5-day window to file claims.

Frequently Asked Questions

1. Do Nattokinase Supplements Lose Potency Over Time?
   They can. Nattokinase is primarily composed of protein molecules, which means that exposure to moisture, heat, or light may reduce its enzymatic activity. Therefore, it is advisable to check for stability testing or expiration dates before selecting nattokinase supplements.
2. Is Taking Nattokinase Supplement Safe If I Have Clotting Disorders?
   No. Using nattokinase supplements in such cases may negatively interfere with blood clotting mechanisms, which may even worsen conditions like hemophilia or platelet dysfunction.
3. Can Nattokinase Formulations Manage Deep Vein Thrombosis (DVT)?
   No. Clinical guidelines recommend prescription anticoagulants as the primary treatment for deep vein thrombosis (DVT). Nattokinase formulations may help support vascular health and blood flow, but they are not intended to treat or manage conditions like deep vein thrombosis (DVT).
4. Are Higher-Dose Nattokinase Supplements More Effective?
   Not necessarily, as nattokinase formulations with higher fibrinolytic units (FU) are not always better, it may be because excessive fibrinolytic activity may raise bleeding risks, and studies typically support benefits within a 100–200 mg/day range of nattokinase.

Conclusion

Nattokinase supplements may support your cardiovascular and circulatory health. They may promote fibrinolysis, the natural breakdown of excess fibrin in the blood, which could help improve blood circulation and support vascular integrity.

It is important to consider some factors before opting got a nattokinase supplement brand to make an informed purchase decision.

These factors include checking the nattokinase enzyme potency (measured in fibrinolytic units or FU), the source strain (ideally Bacillus subtilis natto), and formulation quality (such as enteric capsule coating and additive-free formula).

However, the blood-thinning effects of nattokinase formulations may heighten bleeding risk, particularly if you take anticoagulants or are scheduled for surgery. Nattokinase supplements may also trigger potential side effects, such as bloating, dizziness, stomach upset, hypotension, diarrhea, or even severe allergic reactions. Therefore, as with any supplement that affects the circulatory system, medical supervision is advised when taking nattokinase supplements.

Moreover, nattokinase formulations may work best when integrated into a broader lifestyle approach. Engaging in regular exercise, practicing yoga or meditation, and getting at least 7-9 hours of daily sleep may be helpful. Following a heart-friendly diet rich in omega-3s, fiber, and antioxidants may also naturally support circulation and cardiovascular function.