Can nattokinase clean arteries?

The most rigorous human trial ever run on nattokinase and artery plaque tracked 265 adults for three years — and the supplement performed no better than a placebo.

That result reframes a popular question. "Cleaning" an artery means clearing cholesterol-based plaque, which is a different process from the blood-clot breakdown nattokinase is actually known for. Here is what the evidence shows — and what genuinely clears arteries.

Table of Contents

• What "Cleaning Arteries" Really Means
• What Nattokinase Actually Does in the Body
• Can Nattokinase Clean Arteries? What the Strongest Study Found
• The Higher-Dose Studies: Promising but Preliminary
• What Nattokinase Can Realistically Support
• What Actually Clears and Stabilizes Arteries
• Choosing a Nattokinase Supplement: The BioAbsorb Approach
• Frequently Asked Questions
• Conclusion
• Research References

What "Cleaning Arteries" Really Means

When people ask whether something can "clean" their arteries, they are almost always describing atherosclerosis — the slow buildup of cholesterol-rich plaque inside artery walls that Harvard Health describes as the accumulation of cholesterol-laden plaque and the root cause of most heart attacks and strokes. This plaque is a stubborn, fibrofatty deposit that develops over decades, not a loose bit of debris that a pill can rinse away.

That distinction matters, because "reducing plaque" is a high bar. Cleveland Clinic cardiologists note that even the medications proven to lower cholesterol work mainly by limiting new buildup and stabilizing existing plaque so it is less likely to rupture. Meaningful regression of plaque is possible, but it typically requires driving LDL cholesterol to very low levels over months to years. And because a sudden rupture of plaque is what triggers most heart attacks, stabilizing that plaque matters as much as shrinking it.

A blood clot is a different thing entirely. Clots are meshes of a protein called fibrin that form quickly in response to injury or sluggish flow, and they can be broken down by the body's own enzymes within hours. Keep that fibrin-versus-plaque split in mind, because it is the key to understanding what nattokinase can and cannot do.

What Nattokinase Actually Does in the Body

Nattokinase is an enzyme extracted from natto, a fermented soybean food. It was discovered in 1987 by researcher Hiroyuki Sumi, who found this 275-amino-acid protein could dissolve artificial fibrin in a laboratory dish.

Its documented mechanism is fibrinolytic — it works on clots. Nattokinase directly breaks down fibrin, degrades plasminogen activator inhibitor-1 (PAI-1), and boosts tissue plasminogen activator (t-PA), the body's own clot-clearing signal. In short, it helps the body dissolve fibrin faster.

Here is the critical point for the "clean arteries" question: nattokinase acts on fibrin, not on cholesterol plaque, and it does not even block the formation of new fibrin. No high-quality human study has shown it strips cholesterol deposits from artery walls. Mechanistically, "cleaning arteries" in the plaque sense sits outside what this enzyme is established to do.

A simple analogy helps. Think of a blood clot as a fresh tangle of netting that can drift into a pipe and block it — nattokinase is good at cutting up that netting. Atherosclerotic plaque is more like mineral scale bonded to the inside of the pipe over years; clearing it takes a different, slower process aimed at the cholesterol that builds it. Nattokinase is a netting-cutter, not a scale remover.

Can Nattokinase Clean Arteries? What the Strongest Study Found

The best evidence on this exact question comes from the Nattokinase Atherothrombotic Prevention Study (NAPS), a double-blind randomized trial of 265 adults (median age 65.3) run by researchers at USC's Keck School of Medicine. Participants took either 2,000 FU of nattokinase daily or a matching placebo for a median of 3 years, with carotid ultrasound every 6 months.

The result was a clean null. After 3 years, the rate of change in carotid intima-media thickness and artery stiffness — the gold-standard measures of subclinical atherosclerosis — did not differ between nattokinase and placebo. There was also no effect on blood pressure or any laboratory marker.

This is the largest, longest, and highest-quality trial available, which makes its answer hard to argue with: at the 2,000 FU dose found in typical supplements, nattokinase did not slow plaque, let alone remove it. None of the coagulation or fibrinolysis markers measured shifted meaningfully either. One honest limitation is that participants were healthy and at low cardiovascular risk, so the trial tested prevention of progression rather than clearing of established disease — but even that modest goal was not met.

The Higher-Dose Studies: Promising but Preliminary

Some studies do report plaque changes — but they used much higher doses and weaker designs. A small 2017 trial of 82 patients with carotid atherosclerosis found that 6,000 FU per day for 26 weeks reduced carotid plaque area by 36.6% and wall thickness by about 10.6%. In that trial the plaque reduction actually outpaced the roughly 11.5% change seen with simvastatin, though the statin lowered cholesterol more. Still, it was a single, small, Chinese-language study.

A larger 2022 study of 1,062 older adults reported that 10,800 FU per day for 12 months reduced carotid plaque and thickness and improved lipids — while a lower dose of 3,600 FU per day was ineffective. Crucially, that study was observational rather than randomized, so it cannot prove nattokinase caused the changes, and some participants also took vitamin K2 or aspirin. Reported improvement rates also ranged widely, from 66.5% to 95.4%, which underscores how variable and hard to interpret the observational data were.

The honest synthesis: the encouraging signals appear only at 3 to 5 times the standard supplement dose, and only in lower-quality studies. When a rigorous randomized trial tested the everyday 2,000 FU dose, the plaque benefit disappeared.

What Nattokinase Can Realistically Support

Nattokinase is not useless — it simply works in a different lane. A 2023 meta-analysis of 6 randomized trials and 546 participants found nattokinase modestly lowered systolic blood pressure by 3.45 mmHg and diastolic by 2.32 mmHg, positioning it as a possible adjunct for hypertension.

Its most consistent role is fibrinolytic support — helping the body break down fibrin and supporting healthy blood flow, which is the mechanism documented across animal and human research, where a single oral dose can measurably raise the blood's clot-dissolving activity for several hours after intake. This clot-and-circulation lane, not plaque removal, is where the evidence is strongest.

Two honest caveats keep expectations realistic. First, that same 2023 meta-analysis found no reliable cholesterol-lowering effect at typical doses, so nattokinase is not a substitute for a proven lipid-lowering plan. Second, the blood-pressure benefit was absent in the NAPS trial's healthy, low-risk group, suggesting any effect may be limited to people who actually have elevated readings.

What Actually Clears and Stabilizes Arteries

If the goal is genuinely to reduce or stabilize plaque, the proven tools are well established. Statins lower LDL cholesterol and stabilize plaque, making arteries measurably safer even when the plaque itself does not shrink dramatically.

More intensive lipid lowering can go further. In the Cleveland Clinic-led GLAGOV trial, adding a PCSK9-inhibitor injection to statins pushed LDL to an average of 36.6 mg/dL — a record low in a major trial — and produced measurable regression of coronary plaque. Lifestyle change matters too: Harvard Health notes that intensive dietary and exercise programs can partially reverse coronary artery disease.

Against that backdrop, nattokinase is best viewed as a possible complement for the clot-and-circulation side of cardiovascular health, under medical guidance — never a replacement for proven therapy. If you are on prescribed treatment, the evidence is clear that you should not stop it in favor of a supplement.

Choosing a Nattokinase Supplement: The BioAbsorb Approach

If you and your doctor decide nattokinase fits your plan for the fibrinolytic and circulatory support the evidence does back, consistency and quality matter more than marketing claims. The BioAbsorb Nattokinase Enzyme delivers 100 mg (2,000 FU of activity) per capsule, and every batch is third-party tested to confirm at least 2,000 FU alongside screening for heavy metals, gluten, and microbial contaminants.

Rather than a phthalate-coated enteric capsule, it uses a DRcaps delayed-release veggie capsule that carries the enzyme intact past stomach acid to the small intestine, taken as a single capsule daily on an empty stomach. It is manufactured in a Canadian GMP-certified facility, is 100% vegetarian, and is free of gluten, nuts, eggs, dairy, fish, and shellfish. The formula is deliberately vitamin K2-free, which some people prefer if they already supplement K2 separately.

One honest note on positioning: 2,000 FU is the standard supplemental dose — the same dose the definitive NAPS trial found did not affect plaque. BioAbsorb offers it for general fibrinolytic and circulatory support at roughly $0.28 per day in the 180-count size, not as a plaque-removal product. Anyone taking blood thinners or managing a cardiovascular condition should speak with a physician before starting.

Frequently Asked Questions

Can nattokinase remove existing plaque from my arteries?

There is no reliable evidence that nattokinase removes plaque at standard doses. The strongest trial, NAPS, found no effect on carotid plaque after 3 years at 2,000 FU. A few higher-dose studies are encouraging but preliminary, so plaque removal remains unproven.

Is nattokinase the same as a blood thinner?

Not exactly. Nattokinase has mild fibrinolytic, clot-dissolving activity, but it is not a substitute for prescribed anticoagulants. The clinical literature includes a case of valve thrombosis in a patient who replaced warfarin with nattokinase after mechanical valve surgery. Its clot-dissolving effect is real but not standardized or monitored the way prescription anticoagulation is.

What dose of nattokinase is used in studies?

Most supplements provide 2,000 FU, the dose tested in the null NAPS trial. The studies that reported plaque changes used far more — 6,000 to 10,800 FU per day — and even those found 3,600 FU ineffective.

Can I take nattokinase with warfarin or aspirin?

Only with a doctor's oversight. Combining nattokinase with anticoagulant or antiplatelet drugs can raise bleeding risk, and there are case reports of serious bleeding. Never add it to a blood-thinning regimen without medical advice.

Does nattokinase lower cholesterol?

Not reliably at typical doses. The 2023 meta-analysis of 6 trials found no dependable lipid-lowering effect from standard-dose nattokinase, so it should not replace a proven cholesterol plan.

So what actually cleans arteries?

The proven approach is lowering LDL cholesterol through statins or other lipid-lowering therapy, combined with diet, exercise, and not smoking. These measures stabilize and can partially regress plaque in a way no supplement has matched. Consistency over years, not a single "artery-cleaning" product, is what the evidence rewards.

Conclusion

Nattokinase is a legitimate fibrinolytic enzyme with modest blood-pressure support, but "cleaning arteries" overstates it — the strongest 3-year trial found no plaque effect at the standard 2,000 FU dose. If you want nattokinase for the circulatory support the evidence does back, choose a tested, consistent product and pair it with proven basics under a doctor's guidance. You can explore a third-party-tested option in the BioAbsorb Nattokinase Enzyme.

Research References

1. Nattokinase Atherothrombotic Prevention Study: A Randomized Controlled Trial. Clinical Hemorheology and Microcirculation, Vol. 78(4):339–353 (2021). A 3-year double-blind RCT of 265 adults found 2,000 FU/day nattokinase had a null effect on carotid intima-media thickness, arterial stiffness, and blood pressure versus placebo.
2. Nattokinase Supplementation and Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Reviews in Cardiovascular Medicine, Vol. 24(8):234 (2023). Pooling 6 RCTs (546 participants), nattokinase reduced systolic BP by 3.45 mmHg and diastolic by 2.32 mmHg but showed no reliable lipid-lowering effect.
3. Effective Management of Atherosclerosis Progress and Hyperlipidemia with Nattokinase: A Clinical Study with 1,062 Participants. Frontiers in Cardiovascular Medicine, Vol. 9:964977 (2022). An observational study reporting that 10,800 FU/day for 12 months reduced carotid plaque and thickness, while 3,600 FU/day was ineffective.
4. A Clinical Study on the Effect of Nattokinase on Carotid Artery Atherosclerosis and Hyperlipidaemia. National Medical Journal of China (Zhonghua Yi Xue Za Zhi), Vol. 97(26):2038–2042 (2017). A small randomized trial (82 patients) reporting a 36.6% reduction in carotid plaque area with 6,000 FU/day over 26 weeks.
5. Nattokinase: An Oral Antithrombotic Agent for the Prevention of Cardiovascular Disease. International Journal of Molecular Sciences, Vol. 18(3):523 (2017). A mechanism review describing how nattokinase hydrolyzes fibrin, degrades PAI-1, and raises t-PA to support fibrinolysis.
6. Nattokinase: A Promising Alternative in Prevention and Treatment of Cardiovascular Diseases. Biomarker Insights, Vol. 13 (2018). A narrative review of nattokinase's fibrinolytic, antihypertensive, and putative anti-atherosclerotic effects, noting limited human data.
7. Can Statins Actually Reverse Plaque Buildup? Cleveland Clinic (2025). Explains that statins lower LDL cholesterol and stabilize arterial plaque, reducing heart-attack and stroke risk.
8. Cleveland Clinic-Led Study Shows Reversal of Coronary Plaque Buildup With Injectable Cholesterol Drug (GLAGOV). Cleveland Clinic Newsroom (2016). Adding a PCSK9 inhibitor to statins lowered average LDL to 36.6 mg/dL and produced measurable regression of coronary plaque on intravascular ultrasound.
9. Ask the Doctor: Is It Possible to Reverse Coronary Artery Disease? Harvard Health Publishing. Describes how intensive lifestyle change and lipid-lowering can partially reverse atherosclerosis, largely by stabilizing plaque.
10. Nattokinase — Professional Monograph. Drugs.com. Summarizes bleeding-risk interactions with anticoagulant and antiplatelet drugs, including case reports of hemorrhage and of valve thrombosis after substituting nattokinase for warfarin.

About the Author

David Kimbell is a health writer, digital entrepreneur and former aerospace engineer, based in Ottawa, Canada. He loves translating complex science into clear, actionable guidance for consumers seeking evidence-based solutions.

---

Important Disclaimers

Medical Disclaimer: This article provides educational information only and is not intended as medical advice. Always consult with a qualified healthcare provider before starting any new supplement, especially if you have existing health conditions, take medications, or are pregnant or nursing.

FDA/Health Canada Statement: These statements have not been evaluated by the Food and Drug Administration or Health Canada. This product is not intended to diagnose, treat, cure, or prevent any disease.