Nattokinase: a traditional Japanese enzyme, now studied for cardiovascular and blood-flow research.

Nattokinase is a fibrinolytic enzyme isolated from natto - a traditional Japanese food made from fermented soybeans that's been part of the daily diet in parts of Japan for over a thousand years. The enzyme was first identified and characterised by Dr Hiroyuki Sumi at the University of Chicago in 1980, and since then it has been the subject of increasing scientific interest, particularly in the context of cardiovascular and circulatory research.

This Feel Supreme product delivers 4,000 FU (Fibrinolytic Units) of organic nattokinase per capsule - on the higher end of dosages used in published clinical studies - paired with 300mg of organic inulin from Jerusalem artichoke, which acts as a prebiotic fibre.

What the research is looking at

Nattokinase has been studied in human trials primarily for its effects on blood clotting and circulation. The mechanism is well characterised: nattokinase breaks down fibrin (a protein involved in blood clot formation) and influences several pathways involved in the body's natural clot-clearing system. A comprehensive review published in Biomarker Insights describes how nattokinase interacts with fibrin, plasminogen activators, and other components of the fibrinolytic cascade.

A 2022 clinical study published in Frontiers in Cardiovascular Medicine, involving 1,062 participants, examined nattokinase supplementation in adults and measured markers of arterial health and lipid profiles. It's one of the larger nattokinase studies published to date.

To be clear: nattokinase is a food supplement, not a medicine. We don't make claims that it treats, prevents, or cures any condition. The research above is published, peer-reviewed and citable - but it describes what scientists are investigating, not what this product does for any individual.

Why with inulin?

Inulin is a prebiotic fibre derived in this product from organic Jerusalem artichoke. Unlike most fibres, inulin passes through the upper digestive tract intact and is fermented by beneficial bacteria in the large intestine, producing short-chain fatty acids that the gut wall uses for fuel. It supports a healthy gut microbiome and improves the texture of digestive transit.

Pairing nattokinase with inulin in a single capsule means you're feeding the gut alongside the enzyme delivery. It's a small touch but a sensible one - particularly for anyone whose digestion benefits from extra prebiotic support.

How to take it

One capsule daily, with water. The 60-capsule bottle is a 2-month supply at the recommended dose. You can take it any time of day, with or without food. Consistency matters more than timing - the research base on nattokinase generally uses 4-12 weeks of daily supplementation.

Important safety information

Because nattokinase affects fibrin and blood-clotting pathways, it is essential to be aware of the following:

• If you are taking anticoagulant or antiplatelet medication (such as warfarin, apixaban, rivaroxaban, dabigatran, aspirin, clopidogrel) - do not take nattokinase without first speaking to your doctor. The combination may increase bleeding risk.
• If you have a bleeding disorder, are scheduled for surgery within the next two weeks, or have a history of haemorrhagic stroke - consult your GP before use.
• If you are pregnant or nursing - do not use.
• If you have a soy allergy - this product is derived from fermented soybeans and is not suitable.

This isn't standard supplement boilerplate - nattokinase has measurable biological activity on blood clotting, which is why the safety guidance is more specific than for most supplements. If you're on any prescription medication, particularly cardiovascular medication, please consult your doctor before starting.

Full ingredient breakdown

Suitable for vegans and vegetarians. Non-GMO. No fillers or artificial preservatives.

Why this nattokinase?

Feel Supreme's nattokinase is sourced from certified organic Brazilian soybeans and standardised to 4,000 FU per capsule - on the higher end of the dosages used in published clinical research, which typically range from 2,000 to 4,000 FU per day. The pairing with prebiotic inulin in a single capsule is unusual in the Irish market; most nattokinase supplements deliver the enzyme alone.