Nattokinase vs Serrapeptase: Systemic Enzymes for…

Systemic proteolytic enzymes—taken on an empty stomach to act throughout the body rather than just in the gut—have attracted considerable interest for cardiovascular support, inflammation reduction, and fibrin (scar tissue) breakdown. Nattokinase and serrapeptase are the two most studied options, with meaningfully different evidence bases.

What Is Nattokinase?

Nattokinase is an enzyme extracted from natto, a traditional Japanese fermented soybean food. It has direct fibrinolytic activity—it breaks down fibrin, the protein that forms blood clots, and also inhibits clot formation. Natto's nattokinase content is responsible for the food's unusual blood-thinning reputation in traditional Japanese medicine.

Research supports nattokinase for reducing blood pressure (small but consistent reductions in both systolic and diastolic BP), improving blood viscosity, and reducing fibrinogen levels. A 2008 double-blind trial found that 2,000 FU of nattokinase daily for 8 weeks significantly reduced systolic and diastolic blood pressure in hypertensive patients. It may also reduce the risk of deep vein thrombosis, with some evidence from airline passenger studies.

What Is Serrapeptase?

Serrapeptase (serratiopeptidase) is a proteolytic enzyme originally isolated from the Serratia bacteria found in the digestive tract of silkworms. It breaks down protein-based matter including fibrin, mucus, and dead tissue. In Europe and Asia, it has been used clinically for pain, inflammation, and post-surgical swelling—though it is only available as a supplement in the United States.

Serrapeptase evidence for systemic effects in humans is mixed. Some trials show reductions in swelling and pain after surgery or ENT conditions. The mechanism—dissolving fibrinous protein deposits and dead tissue—is biologically plausible, but large-scale RCTs for cardiovascular or anti-inflammatory applications are lacking.

Comparing the Evidence

Nattokinase has stronger and more consistent clinical evidence for its cardiovascular effects—specifically blood pressure reduction and fibrinolytic activity. The research on nattokinase is conducted in human subjects, uses relevant endpoints, and has been replicated.

Serrapeptase has a more heterogeneous evidence base. Some studies show benefits for localized inflammatory conditions (sinus congestion, post-surgical edema, carpal tunnel pain) while systemic anti-inflammatory effects remain less established. The enzyme is acid-labile and must be enteric-coated to survive stomach acid and reach the small intestine for absorption.

Blood Thinning Caution

Both nattokinase and serrapeptase can affect clotting and should be used with caution in people taking anticoagulants (warfarin, heparin) or antiplatelet drugs (aspirin, clopidogrel). The combination can increase bleeding risk. Always disclose supplement use to prescribing physicians.

Practical Dosing

Nattokinase is measured in FU (fibrinolytic units). Effective research doses are 2,000 FU per day, taken on an empty stomach. Serrapeptase is dosed at 10,000–60,000 SPU per day in enteric-coated form, again on an empty stomach—typically 30 minutes before a meal or 2 hours after.

Who Uses These Enzymes?

Nattokinase is used by people concerned about cardiovascular risk, blood pressure, and clot-related events. Serrapeptase is used for localized inflammatory conditions, chronic sinusitis, and post-surgical recovery. Some practitioners use both together for chronic systemic inflammation or cardiovascular-inflammatory conditions.

FAQ

Q: Can I get nattokinase from eating natto instead of supplementing? A: Yes, traditional natto is a rich source. About 100 grams of natto provides roughly 2,000 FU of nattokinase. However, natto has a strong flavor that many Western consumers find challenging, making supplementation practical.

Q: Do systemic enzymes actually reach the bloodstream intact? A: This has been debated. Research using radiolabeled enzymes and serum activity assays confirms that proteolytic enzymes including nattokinase and serrapeptase do reach systemic circulation in bioactive form when properly formulated. The enteric coating requirement for serrapeptase is important for this to occur.

Q: Are there any long-term safety concerns? A: Both enzymes have good safety profiles in clinical studies. The primary concern is drug interactions with anticoagulants. No serious long-term adverse effects have been established at standard doses.

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Nattokinase vs Serrapeptase: Systemic Enzymes for Cardiovascular and Inflammation Support