Nattokinase has quietly become one of the most researched natural enzymes in cardiovascular supplement circles, yet many people have never heard of it outside of Japan, where natto has been a dietary staple for centuries. If you are trying to understand the real nattokinase benefits before adding it to your routine, this guide covers what the enzyme actually does, what the clinical research shows and how to take it properly.
What Is Nattokinase?
Nattokinase is an enzyme extracted from natto, a fermented soybean dish made using the bacterium Bacillus subtilis. During fermentation, the bacteria produce nattokinase as a byproduct, and it is this enzyme, rather than the soybean itself, that has attracted the attention of cardiovascular researchers over the past two decades.
A review published on the National Institutes of Health's PMC database describes nattokinase as possessing a variety of favourable cardiovascular effects, noting that regular consumption of natto has been linked to reduced cardiovascular disease mortality in population studies, and that nattokinase itself demonstrates fibrinolytic, antihypertensive, anti-atherosclerotic and antiplatelet properties1. That is a broad list of potential benefits for a single dietary enzyme, which is why nattokinase has moved from a Japanese dietary curiosity into a mainstream heart health supplement.
Nattokinase Benefits: What the Research Shows
1. Supporting Healthy Blood Flow
Nattokinase's most studied property is its fibrinolytic activity, meaning its ability to help break down fibrin, a protein involved in blood clot formation. Early animal research found nattokinase to be several times more potent than plasmin, the body's own clot-dissolving enzyme, at breaking down artificially induced clots. This is the foundation for most of the ongoing human research into nattokinase for circulation support.
2. Cardiovascular Health Support
A systematic review and meta-analysis of randomised controlled trials involving 546 participants found that nattokinase supplementation had measurable effects on several cardiovascular risk markers, with no significant adverse events reported across the included studies. While researchers note that dosage and standardisation still vary between products, the overall safety profile recorded in these trials is one of the more reassuring aspects of nattokinase as a supplement.
3. Healthy Blood Pressure Levels
One multicentre, randomised, double-blind, placebo-controlled clinical trial found that consumption of nattokinase was associated with reduced blood pressure and reduced levels of von Willebrand factor, a recognised cardiovascular risk marker. This antihypertensive effect is thought to be linked to nattokinase's impact on blood vessel function alongside its clot-dissolving activity.
4. Gut and Digestive Support
Because nattokinase originates from a fermented food, some formulations are paired with prebiotic fibres such as inulin to support gut health alongside cardiovascular benefits. This combination reflects the traditional way natto has always been consumed, as part of a fermented, fibre-rich diet rather than as an isolated enzyme.
How to Take Nattokinase
Nattokinase is typically measured in fibrinolytic units (FU), with most studied doses falling between 2,000 and 4,000 FU per day, usually taken on an empty stomach to maximise absorption. It is generally taken once daily as part of an ongoing routine rather than as a short-term intervention, since its cardiovascular benefits are linked to consistent, cumulative use.
Feel Supreme's Organic Nattokinase with Inulin delivers 4000 FU per capsule alongside inulin for added gut health and digestion support, and sits within the wider Heart & Blood Health collection at Feel Supreme. For those focused specifically on digestive wellbeing, it is also worth browsing the Gut Health & Digestion range.
Who Should Be Cautious With Nattokinase
Because nattokinase affects blood clotting mechanisms, it is not suitable for everyone. Anyone taking blood-thinning medication such as warfarin, aspirin or other anticoagulants should not take nattokinase without first speaking to a GP, since the combined effect on clotting could increase bleeding risk. It should also be avoided before surgery, and those with a soy allergy should check formulations carefully given its soybean origin. As with all supplements, nattokinase is not intended to diagnose, treat, cure or prevent any disease.
Frequently Asked Questions
What are the main nattokinase benefits for heart health?
The main nattokinase benefits for heart health relate to its fibrinolytic activity, meaning its capacity to support the breakdown of fibrin involved in blood clotting, along with research-supported effects on blood pressure and cardiovascular risk markers. These effects are best supported by consistent daily use rather than occasional supplementation, and nattokinase should complement rather than replace any medication prescribed for cardiovascular conditions.
Can nattokinase be taken alongside other supplements?
Nattokinase can generally be combined with most everyday supplements such as vitamins and minerals, though it should not be combined with other blood-thinning ingredients like high-dose fish oil or vitamin E without medical guidance, as the cumulative effect on clotting could be significant. Always check with a pharmacist or GP if you are taking multiple supplements alongside any prescribed medication.
Is nattokinase safe to take every day?
For most healthy adults not taking anticoagulant medication, nattokinase is considered safe for daily use at studied doses, and clinical trials have reported a favourable safety profile with few adverse events. However, anyone with an existing bleeding disorder, upcoming surgery, or blood-thinning prescription should avoid nattokinase unless specifically advised otherwise by a doctor.
How long does it take to notice the benefits of nattokinase?
Most clinical trials studying nattokinase run for several weeks to months, suggesting that its cardiovascular effects build gradually with consistent use rather than appearing immediately. As with most enzyme and circulation-focused supplements, nattokinase is best viewed as a long-term addition to a heart-healthy lifestyle rather than a quick fix.
The Bottom Line
Of all the enzyme-based supplements on the market, nattokinase has one of the stronger and more consistent bodies of clinical research behind it, particularly around blood flow and cardiovascular risk markers. If circulation and heart health are a priority for you, understanding the real nattokinase benefits, and taking a properly dosed, tested formulation daily, is a sensible way to explore what this fermented soy enzyme can offer. Take a look at the full Heart & Blood Health range at Feel Supreme to see how it fits into a broader routine.
Support your heart and gut health daily
Shop Organic Nattokinase with Inulin1 Source: Nattokinase: A Promising Alternative in Prevention and Treatment of Cardiovascular Diseases, PMC/NIH
