Quick Summary

Nattokinase is an enzyme supplement classified under enzymes and digestive support. It is derived from natto, a traditional Japanese fermented soy product. Nattokinase is researched for potential effects on digestion and circulatory system health, particularly through its fibrinolytic activity. However, conclusive human clinical evidence remains limited and inconclusive.

What is it?

Nattokinase is a serine protease enzyme extracted from natto, a fermented soybean food common in Japan. As an enzyme supplement, nattokinase is primarily used for its enzymatic activity that may influence blood flow and fibrinolysis, the process of breaking down fibrin, a protein involved in blood clotting.

How it may work in the body

Summary: Nattokinase may support enzymatic activity related to digestion and blood fibrinolysis, potentially aiding circulatory health by breaking down fibrin.

  • Nattokinase exhibits fibrinolytic enzyme activity that may degrade fibrin, a key protein involved in blood clot formation.
  • Its protease activity could also influence digestive enzyme processes.

Limitations: Mechanistic data supporting these activities are mainly from in vitro (test tube) and animal studies. Human clinical evidence demonstrating these mechanisms and corresponding clinical benefits is limited and inconclusive at this time.

Common supplement forms

  • Capsules
  • Tablets
  • Powders

Typical dosage and how it is used

There is currently no established official recommended daily intake (RDI) or adequate intake (AI) for nattokinase from regulatory or health organizations.

Dosages vary widely depending on the product. Users should adhere to the manufacturer’s instructions and consult healthcare professionals before starting supplementation.

Natural sources

  • Natto (fermented soybean product)

Absorption and bioavailability

Specific data on the absorption and bioavailability of nattokinase in humans are limited. There is currently no evidence identifying differences in absorption between supplement forms or known factors that enhance or inhibit bioavailability.

Potential benefits: what does the evidence say?

Circulatory health and fibrinolysis

Nattokinase has been studied mainly for its potential fibrinolytic effects, which could theoretically support circulatory health by breaking down fibrin and possibly improving blood flow. However, the human clinical trial evidence is limited and not definitive. Many studies have small sample sizes, varying methods, and lack sufficient power to draw firm conclusions.

Digestive support

Classified as a digestive enzyme due to its proteolytic activity, nattokinase may support digestion. Yet, controlled human studies focusing on digestive outcomes are lacking and the clinical evidence to substantiate this claim is insufficient at present.

Summary: Current evidence for nattokinase’s benefits in circulatory health and digestion is insufficient to confirm effectiveness. More rigorous, well-designed human studies are needed.

Side effects and safety

No common side effects or contraindications have been consistently reported in available studies. However, safety data are incomplete. There is insufficient information on potential toxicity, overuse risks, or adverse effects in special populations.

Data on nattokinase safety during pregnancy and breastfeeding are insufficient, so caution is advised.

Drug and supplement interactions

Currently, there are no well-documented interactions between nattokinase and medications or other supplements. Given its fibrinolytic activity, theoretical interactions with blood-thinning drugs may be possible, so consultation with a healthcare provider is recommended before use, especially for individuals taking anticoagulants or antiplatelet agents.

Who should be careful?

  • Individuals with bleeding disorders or on blood-thinning medications should exercise caution due to potential effects on blood clotting.
  • People who are pregnant or breastfeeding should avoid use unless advised by a healthcare professional, as safety data are insufficient.
  • Those planning surgery should consult their healthcare provider before taking nattokinase to avoid potential bleeding complications.
  • Anyone with underlying health conditions or taking medications should seek medical advice prior to taking nattokinase supplements.

Pregnancy, breastfeeding and special populations

There is insufficient data regarding the safety of nattokinase supplementation during pregnancy and breastfeeding. Use in these populations is not currently recommended without professional medical guidance.

Quality, standardization and what to look for

Nattokinase supplements vary in enzyme activity levels, dosages, and formulations. Quality control and standardization are important considerations, but no universal industry standard exists.

Consumers should opt for products from reputable manufacturers that provide clear labeling on enzymatic activity (often measured in fibrinolytic units) and follow good manufacturing practices (GMP).

Frequently asked questions

Is nattokinase safe to take daily?

There is limited safety data for everyday long-term use. Consult a healthcare provider for personalized advice, especially if you take blood thinners or have medical conditions.

Can nattokinase replace medication for blood clotting issues?

Nattokinase is not a substitute for medical treatments. Evidence from human trials is insufficient to support its use as a treatment for blood clotting disorders.

Does nattokinase have EU-authorized health claims?

No official EU-authorized health claims for nattokinase are available based on the current evidence supplied.

Where can I find nattokinase naturally?

Nattokinase is naturally found in natto, a Japanese fermented soybean dish.

Are there different forms of nattokinase supplements?

Yes, nattokinase supplements are available as capsules, tablets, and powders. There is no evidence indicating that one form is superior in effectiveness or absorption.

Evidence limitations

  • Lack of well-powered, high-quality randomized controlled trials in humans limits the reliability of current findings.
  • Most supporting data arise from preclinical and mechanistic studies rather than robust clinical evidence.
  • No standardized dosage guidelines or formulations have been established.
  • Safety and interaction data are limited, requiring cautious use particularly in vulnerable groups.

References

Last reviewed

June 2024

Disclaimer: This page is for informational purposes only and does not provide medical advice. Always consult a healthcare professional before starting any new supplement, especially if you have underlying health conditions, are pregnant, breastfeeding, taking medications, or planning surgery.