The Best Source of Nattokinase: Supplements vs. Traditional Natto

November 17, 2025 •

3 min read

According to the World Health Organization, cardiovascular disease remains the leading cause of death worldwide, prompting a search for natural remedies and preventative measures. The best source of nattokinase, a potent enzyme derived from fermented soybeans, is often debated between traditional food and modern supplements. This guide explores the pros and cons of each, helping you determine the most effective and practical option for your health needs.

Quick Summary

This article analyzes whether traditional natto or modern supplements are the most effective source of the enzyme nattokinase. It compares the two options based on dosage accuracy, absorption, and convenience, providing a clear breakdown to inform your choice.

Key Points

Natto vs. Supplements: While traditional natto is the original source, supplements offer more consistent and controllable dosing of nattokinase.
Dosing Accuracy: Reputable supplements are standardized by fibrinolytic units (FU), providing a reliable dose, unlike the variable enzyme content in fermented natto batches.
Vitamin K2 Concern: For those on blood thinners, a Vitamin K2-free supplement is the safest option, as the high K2 content in natto can interfere with anticoagulant medication.
Absorption: Enteric-coated capsules protect the nattokinase enzyme from stomach acid, potentially improving absorption compared to consuming the whole food.
Allergen Potential: Nattokinase is derived from soy, so individuals with soy allergies should avoid both natto and supplements derived from it.
Consult a Doctor: It is essential to consult a healthcare provider before taking nattokinase, especially if on blood thinners, pregnant, or anticipating surgery.

Natto: The Traditional Source of Nattokinase

For over a thousand years, the Japanese have consumed natto, a dish of fermented soybeans, as a staple of their diet. This traditional food is where the enzyme nattokinase was first discovered in 1987 by Japanese researcher Hiroyuki Sumi. The fermentation process, using the bacterium Bacillus subtilis var. natto, is responsible for producing the sticky, stringy substance rich in nattokinase. Many believe that the high consumption of natto in certain regions of Japan contributes to the country's famously long lifespan.

Benefits and Drawbacks of Natto

Consuming natto provides nattokinase in its most natural, whole-food form, along with other beneficial nutrients like protein, vitamins, and probiotics. However, there are significant drawbacks. For many Westerners, the pungent smell and slimy texture of natto are unappealing, making it difficult to incorporate into a regular diet. Another major consideration is the presence of Vitamin K2 in natto, which plays a role in blood clotting. This can be a concern for individuals on blood-thinning medication like warfarin, as Vitamin K2 can counteract its effects. The enzyme concentration can also vary widely between batches, making consistent dosing impossible.

Nattokinase Supplements: The Modern Alternative

For those who cannot tolerate the taste of natto or require a precise dose, nattokinase supplements offer a practical alternative. The enzyme is extracted, purified, and encapsulated, allowing for easy consumption without the strong flavor and odor of the fermented food. Quality supplements are typically standardized to measure enzyme activity in fibrinolytic units (FU), ensuring a consistent and accurate dosage.

Advantages and Considerations of Supplements

One of the main advantages of a high-quality nattokinase supplement is the removal of Vitamin K2 during the purification process, making it a safer option for those on certain medications. The enzyme can be delivered in enteric-coated capsules, which protect it from stomach acid and ensure it reaches the intestines for optimal absorption. However, the supplement market is unregulated, and quality can vary drastically. Choosing a reputable brand that provides third-party testing for stated FU activity is crucial to ensure efficacy.

Comparison of Nattokinase Sources: Natto vs. Supplements


Feature	Traditional Natto	Nattokinase Supplements
Dosage Control	Inconsistent and varies by batch.	Precise and standardized, measured in FU.
Taste & Odor	Strong, pungent, and often unappealing.	Tasteless and odorless, easily consumed.
Convenience	Can be challenging to find and prepare regularly.	Convenient for daily intake, available globally.
Vitamin K2 Content	High content, which can interfere with some medications.	Typically Vitamin K2-free, suitable for more people.
Bioavailability	Potentially lower due to enzyme degradation in stomach acid.	Optimized for absorption with enteric-coated capsules.
Synergistic Nutrients	Contains other beneficial compounds from whole food.	Often contains only the isolated enzyme.

Choosing the Right Source for You

For most people seeking the cardiovascular benefits of nattokinase, particularly blood-thinning and plaque reduction, a high-quality supplement is the most reliable and consistent source. It offers precise dosing and avoids the challenges of taste and the Vitamin K2 content found in traditional natto. Supplements from reputable brands often undergo rigorous testing to ensure potency and purity.

However, if you are an adventurous eater who enjoys the distinct flavor of traditional Japanese foods, incorporating natto into your diet can provide the enzyme along with other synergistic nutrients and probiotics. This can be a more holistic approach, but it is not suitable for those on anticoagulant therapy without consulting a doctor due to the Vitamin K2 content.

Ultimately, the best source of nattokinase depends on individual preference, health goals, and tolerance. Consulting a healthcare professional before starting any new supplement is advisable, especially for those with pre-existing conditions or those on medication.

Conclusion

When considering the best source of nattokinase, the choice is ultimately between the traditional, whole-food approach of natto and the modern, standardized supplement. While natto provides a holistic nutritional package, its strong taste and variable enzyme content make it less practical for consistent, controlled intake. For therapeutic purposes and consistent dosing, a high-quality nattokinase supplement is the superior option, especially for those sensitive to natto's flavor or needing to avoid Vitamin K2. Whichever route you choose, understanding the benefits and limitations of each source is key to harnessing the power of this promising enzyme for cardiovascular wellness.

Here is an authoritative source on the topic:

Frequently Asked Questions

Not necessarily. While natto offers a holistic nutrient profile, its nattokinase content is variable. A high-quality supplement with standardized FU is a more reliable and consistent way to ensure a specific, therapeutic dose.

Natto contains a high amount of Vitamin K2, which plays a critical role in the blood clotting process. Warfarin is an anticoagulant that works by blocking Vitamin K. Consuming natto can counteract the effects of warfarin and be dangerous for those on this medication.

Nattokinase is produced by the bacterium Bacillus subtilis during the fermentation of soybeans. For supplements, the enzyme is isolated and purified from the fermented soybeans, and the Vitamin K2 is typically removed.

FU stands for Fibrinolytic Units, a standard measure of the enzyme's activity. When choosing a supplement, it is crucial to check the FU count rather than just the milligrams, as this indicates the enzyme's potency. High-quality products typically offer at least 1,000 FU per dose.

Nattokinase is generally well-tolerated. However, due to its effect on blood thinning, the main risk is increased bleeding, especially for those on other blood-thinning medications. Mild gastrointestinal discomfort has also been reported.

Pregnant or breastfeeding women, children, and those with bleeding disorders should not take nattokinase. Additionally, anyone on blood-thinning medications or anticipating surgery should consult a doctor first.

Yes, research suggests that nattokinase has potent fibrinolytic activity, meaning it can help break down the protein fibrin, which is the main component of blood clots.

Some studies indicate that nattokinase may help lower blood pressure. In one randomized, controlled trial, participants who took nattokinase saw a reduction in both systolic and diastolic blood pressure.