Nattokinase vs. Serrapeptase: Comparing Fibrinolytic Enzymes

Nattokinase and serrapeptase are both proteolytic (protein-breaking) enzymes marketed for circulatory and inflammatory support, but they come from different sources, work through different mechanisms, and have different levels of clinical evidence. Nattokinase, derived from the Japanese food natto, has stronger research supporting its role in promoting healthy fibrin metabolism and circulation. Serrapeptase, originally isolated from silkworm bacteria, is used more for its anti-inflammatory properties. Understanding these differences helps you choose the right enzyme for your goals.

Quick Comparison Table

What Is Nattokinase?

Nattokinase is a fibrinolytic enzyme produced during the fermentation of soybeans into natto, a traditional Japanese food. It was first identified by Dr. Hiroyuki Sumi in 1987. Nattokinase works primarily by directly breaking down fibrin — the protein mesh that forms blood clots — and by enhancing the body's own fibrinolytic system. Clinical research published on PubMed has demonstrated that nattokinase supplementation supports healthy circulation and fibrin metabolism. It is measured in fibrinolytic units (FU), with typical supplemental doses ranging from 2,000 to 4,000 FU daily. Nattokinase is one of the most well-researched natural fibrinolytic enzymes available.

What Is Serrapeptase?

Serrapeptase (also known as serratiopeptidase) is a proteolytic enzyme originally isolated from Serratia marcescens bacteria found in the intestines of silkworms. The silkworm uses this enzyme to dissolve its cocoon. In supplement form, serrapeptase is used primarily for its ability to break down inflammatory proteins and support tissue recovery. It has been studied in clinical settings for post-surgical swelling and sinus comfort. Serrapeptase requires enteric coating to survive stomach acid and reach the small intestine intact. Its research base, while growing, is smaller and less consistent than that of nattokinase, with some studies showing clear benefits and others producing mixed results (NIH).

Key Differences

1. Primary Mechanism

Nattokinase is specifically fibrinolytic — it targets and breaks down fibrin, the structural protein of blood clots. This makes it relevant for circulatory support. Serrapeptase is more broadly proteolytic — it breaks down various proteins involved in inflammation, including bradykinin and other inflammatory mediators. Their targets overlap slightly but serve different primary health goals.

2. Clinical Evidence

Nattokinase has a stronger and more consistent body of clinical evidence, particularly for circulatory health markers. Multiple randomized controlled trials and human studies indexed on PubMed support its fibrinolytic activity and safety profile. Serrapeptase research is more mixed — some studies show meaningful benefits for post-surgical recovery and sinus comfort, while others have been criticized for methodological limitations.

3. Delivery and Stability

Serrapeptase is highly sensitive to stomach acid and must be delivered in enteric-coated capsules to remain effective. Without enteric coating, the enzyme is largely destroyed before reaching the intestines. Nattokinase is more stable in the digestive tract, though quality manufacturers still optimize delivery for maximum activity. This stability difference is a practical consideration when evaluating products.

4. Safety and Medication Interactions

Both enzymes can theoretically affect blood clotting parameters. Anyone taking anticoagulant or antiplatelet medications (such as warfarin, aspirin, or clopidogrel) should avoid these supplements unless specifically approved by their healthcare provider. Both should be discontinued before surgical procedures as a precaution. Nattokinase, in particular, has documented interactions with blood-thinning medications (PubMed).

Which Should You Choose?

Choose nattokinase if your primary interest is circulatory support and healthy fibrin metabolism — it has the stronger evidence base and more direct mechanism for these goals. Choose serrapeptase if you are specifically interested in supporting healthy inflammatory response and tissue recovery, though be aware the evidence is less robust. Some practitioners recommend combining both for comprehensive enzyme support. Regardless of which you choose, discuss proteolytic enzyme supplementation with your healthcare provider, especially if you take any medications.

Our Recommendation

Utzy Naturals Nattokinase provides a clinically relevant dose of nattokinase enzyme measured in fibrinolytic units (FU) to support healthy circulation and fibrin metabolism. Utzy Naturals selected nattokinase based on the strength of clinical evidence supporting its role in cardiovascular wellness and its well-characterized safety profile. As with all Utzy Naturals products, quality and purity are verified through rigorous testing.

Frequently Asked Questions

Can I take nattokinase and serrapeptase together?

Some people do take both enzymes together for combined fibrinolytic and anti-inflammatory support. However, because both can affect clotting parameters, combining them increases the importance of medical oversight. Consult your healthcare provider before stacking proteolytic enzymes.

Should I take nattokinase on an empty stomach?

Many practitioners recommend taking proteolytic enzymes on an empty stomach (at least 30 minutes before meals or 2 hours after) for systemic enzyme activity. When taken with food, the enzymes may act on food proteins rather than performing their intended systemic function.

Is nattokinase safe for people with soy allergies?

Nattokinase is derived from fermented soybeans, which raises concern for those with soy allergies. However, the fermentation process breaks down most soy proteins. Some manufacturers produce soy-free nattokinase. If you have a soy allergy, look for products specifically labeled soy-free and consult your allergist.

How long does it take to notice benefits from nattokinase?

Research suggests that nattokinase begins affecting fibrinolytic markers within hours of a single dose, but consistent supplementation over several weeks is recommended for sustained circulatory support benefits. Individual responses vary.

Why does serrapeptase need enteric coating?

Serrapeptase is destroyed by stomach acid. Enteric coating protects the enzyme capsule through the acidic stomach environment, allowing it to dissolve and release the active enzyme in the more alkaline small intestine where it can be absorbed.

Are there food sources of these enzymes?

Nattokinase is naturally present in natto, the traditional Japanese fermented soybean dish. There are no common food sources of serrapeptase — it is exclusively available as a supplement derived from bacterial fermentation.

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