Written by the BioBodyBoost Team · August 2026 · Our standards →
Quick answer: the clinically studied nattokinase dose is 2000 FU (fibrinolytic units) per day — usually 100mg of standardised extract — taken consistently for 8+ weeks. FU, not milligrams, is the number that matters, because it measures actual enzyme activity. Anyone on anticoagulants (warfarin, DOACs) or antiplatelet medication should not take nattokinase without speaking to their GP first.
What does 2000 FU actually mean?
Nattokinase is an enzyme, so its potency is measured by activity — fibrinolytic units — rather than weight. Two products can both say "100mg" while delivering very different enzyme activity. 2000 FU is the dose used in the key clinical trials, including the double-blind trial in Hypertension Research that found significant reductions in systolic and diastolic blood pressure over 8 weeks. If a label lists only milligrams with no FU value, you cannot verify the dose against the research.
How does nattokinase work?
Nattokinase dissolves fibrin — the protein mesh that forms blood clots — and activates plasminogen, your body's own clot-dissolving system. The practical result is improved blood fluidity and reduced fibrinogen, a cardiovascular risk marker. This is a genuinely different mechanism from blood-pressure supplements like beetroot, which work through vasodilation. We compare the two in full here: Nattokinase vs beetroot: which is better and can you take both?
When and how to take it
Take nattokinase once daily, ideally away from large meals — many people take it in the evening, reflecting the traditional pattern of eating natto at dinner in Japan. Effects on fibrinolytic markers build over 8–12 weeks of consistent use. It is a maintenance supplement, not an acute intervention.
Who should NOT take nattokinase without medical advice: anyone on warfarin or other anticoagulants, anyone on antiplatelet medication (including daily aspirin), anyone with a bleeding disorder, anyone scheduled for surgery within two weeks, and anyone who is pregnant or breastfeeding. Nattokinase has real fibrinolytic activity — the same mechanism that makes it useful can add to the effect of blood-thinning medication.
Is nattokinase halal?
Natto is fermented soybean, so nattokinase is plant-derived by origin — but capsule material and processing determine the final status. CardioVital delivers 2000 FU nattokinase (100mg standardised) with selenium in a plant-derived capsule — halal approved, vegan, UK made.
Frequently asked questions
Can I take nattokinase with beetroot?
Generally yes — they act through separate pathways and are commonly combined. The exception is if you take anticoagulants or prescribed blood pressure medication; speak to your GP first.
How long before surgery should I stop nattokinase?
Standard guidance for supplements with fibrinolytic or anticoagulant-adjacent activity is to stop at least two weeks before any scheduled surgery and tell your surgical team you were taking it.
Does nattokinase contain soy allergen?
It is derived from soy fermentation. Sensitivity varies by individual and by how the extract is purified — check the product page allergen statement before buying.
Explore the full Halal Vitamins UK collection.
Food supplements should not replace a varied diet or healthy lifestyle. This article does not constitute medical advice. If you take prescription medication — particularly anticoagulants or antihypertensives — consult your GP before starting nattokinase.
