Nattokinase is 1 of the very few supplements measured in activity rather than in weight, in units called FU. That is why 2 bottles listing the same milligrams can differ.
The number that matters is 2000 FU, and products on sale go as high as 10800 FU.
Quick Answer: How Much Nattokinase Should You Take?
The dose with the clearest trial behind it is 2000 FU, used in a double-blind crossover study in 12 healthy men. FU stands for fibrin units and measures enzyme activity, not weight, so 2000 FU is about 100 mg. Retail products reach 8000 and 10800 FU, and no trial supports those amounts. Our label is 2000 FU once daily.
Key Takeaways
- FU means fibrin units, 1 measure of activity rather than of weight.
- 2000 FU is the dose used in the single-dose crossover trial.
- 2000 FU corresponds to roughly 100 mg of the enzyme itself.
- Retail products reach 10800 FU, with 0 trials at that level.
- Our label is 1 capsule of 2000 FU, taken once a day.
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What FU Actually Means
Milligrams tell you how much material is in a capsule. Fibrin units tell you how much work the enzyme in it can do, which is not the same question.
- FU: Fibrin units, an activity measure.
- Why activity: Enzyme potency varies between batches and makers.
- Rough conversion: 2000 FU is about 100 mg of enzyme.
- What this means: Compare labels on FU, never on milligrams.
Two products both saying 100 mg can differ in activity. What the enzyme is doing is in the enzyme explained.
Why 2000 FU Is the Number
It is not a marketing figure. It is the amount that was put into people and measured.
| Study | Dose | Design |
|---|---|---|
| Single-dose crossover, 2016 | 2000 FU | Double-blind, placebo-controlled, 12 healthy men |
| Randomized trial, 2019 | Daily supplementation | 50 nattokinase and 50 placebo |
| Atherothrombotic prevention, 2021 | Daily, long term | 265 adults, median age 65.3 |
| Nattokinase plus monascus, 2023 | Daily, 4 months | 113 subjects, 2 active ingredients |
The crossover trial administered a single dose of 2000 FU and measured coagulation and fibrinolysis parameters.[1]A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles — Scientific Reports (2016) View source The 2023 dyslipidemia trial is often quoted for nattokinase, but it tested nattokinase together with monascus and cannot separate the 2.[2]The Effect of Nattokinase-Monascus Supplements on Dyslipidemia: A Four-Month Randomized, Double-Blind, Placebo-Controlled trial — Nutrients (2023) View source
What About 8000 and 10800 FU
These are real products with real search demand, and there is a simple thing to say about them.
- Trials above 2000 FU: 0 with a clear safety and efficacy readout.
- What more activity means: More fibrinolysis, so more bleeding risk.
- Who is most exposed: The same groups the case reports describe.
- Our position: We do not sell above the studied amount.
A higher number on a label is not evidence of a better product here. It is a step further from anything that was tested, and the bleeding cases are in the interaction rules.
Our Label, Stated Plainly
What is in the bottle, including the part that is not nattokinase.
- Nattokinase: 2000 FU, about 100 mg.
- Proprietary blend: 1000 mg of garlic and turmeric.
- Per bottle: 60 vegan capsules.
- At 1 daily: 2 months of use.
A bottle of our label at 2000 FU is 2 months at 1 capsule a day, with the enzyme at the studied amount.
Timing, Food and Duration
None of this is trial-established, so it is stated as convention rather than as evidence.
- Timing: Commonly taken in the evening, on convention alone.
- Food: With food reduces the chance of mild stomach upset.
- Duration: The 2021 trial ran long term in 265 adults.
- Review point: Any new bruising or bleeding means stop, not adjust.
The longest run of daily use on record is the 2021 prevention trial, in 265 adults of median age 65.3.[3]Nattokinase atherothrombotic prevention study: A randomized controlled trial — Clinical Hemorheology and Microcirculation (2021) View source
- Longest trial: The 2021 study, run long term.
- Participants: 265 adults, median age 65.3.
- Major adverse events: 0 reported in it.
- What it did not test: Doses above the studied amount.
Why vitamin K2 keeps turning up on the same labels is in why K2 is sold alongside it.
Do Not Adjust a Dose, and Speak to a Clinician First, If
- You take warfarin, a DOAC, aspirin, clopidogrel or any other anticoagulant or antiplatelet
- You have a mechanical heart valve, a stent or any implanted cardiac device
- You have a bleeding disorder such as haemophilia, or a history of haemorrhagic stroke
- You have surgery or a dental procedure booked within the next 2 weeks
- You are pregnant, breastfeeding, or allergic to soy or natto
Frequently Asked Questions
Is it okay to take nattokinase every day? +
The 2021 trial ran long term in 265 adults with no major adverse events. Daily use still needs checking against any medication you take.
How much nattokinase should I take a day? +
2000 FU is the amount with the clearest trial behind it, and that is our label. 0 trials support the 10800 FU products.
What does 2000 FU mean? +
2000 fibrin units of enzyme activity, roughly 100 mg of enzyme. It is an activity measure, not a weight.
Is 10000 FU better than 2000 FU? +
There is no evidence that it is. Above 2000 FU there are 0 trials, and more activity means more bleeding risk.
Should I take nattokinase morning or night? +
Convention favours the evening and 0 trials have compared the 2. Taking it with food reduces stomach upset.
Can I take 2 capsules a day? +
That doubles you past the studied amount. There is no trial at 4000 FU, so the answer is to ask before doing it.
How long does it take to work? +
The single-dose trial saw marker changes within hours in 12 men. Whether that translates into anything you notice has not been measured.
Does the garlic and turmeric blend matter? +
It is 1000 mg of the capsule and it is proprietary, so the split is not disclosed. The 2000 FU enzyme figure is the part that matches the trials.
Should I take it with food? +
With food is the safer default, because the 1 common complaint is mild stomach upset.
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