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At a Glance
- Short-term trials Nattokinase lowered blood pressure modestly in 8-week trials, by about 5.6/2.8 mmHg in one1 and about 3.5/2.3 mmHg on average across 6 trials3.
- Long-term trial In the 3-year NAPS trial of 265 adults, nattokinase had no effect on blood pressure4.
- Dose studied 2,000 FU a day in most trials14.
- Not a replacement for medicine It isn’t a substitute for prescribed blood pressure treatment, and it adds bleeding risk for some people5.
- Top pick Nutricost Nattokinase 2,000 FU – the #1 pick in our guide to the best nattokinase supplements: one capsule a day at the 2,000 FU dose used in blood pressure trials.
The Short Answer: Nattokinase may lower blood pressure slightly, but the evidence is mixed. Two 8-week trials found small drops12, and a 2023 meta-analysis of 6 trials found an average reduction of about 3.5 mmHg systolic and 2.3 mmHg diastolic3. But the longest and largest trial, which gave 2,000 FU a day for about 3 years, found no effect on blood pressure4.
On this page
So nattokinase isn’t a reliable way to treat high blood pressure. If you want to try it alongside your usual care, measure your blood pressure before and after, and check with your doctor first. Compare products in our guide to the best nattokinase supplements.
Nattokinase Blood Pressure Trials
| Study | Who | Dose and length | Result |
|---|---|---|---|
| Kim 20081 | 73 adults, high-normal or stage 1 BP | 2,000 FU/day, 8 weeks | About 5.6/2.8 mmHg lower vs placebo |
| Jensen 20162 | 74 adults with high BP | 100 mg/day, 8 weeks | Diastolic 87 → 84 mmHg; larger effect in men |
| Meta-analysis 20233 | 6 trials, 546 people | Various | About 3.5/2.3 mmHg lower vs placebo |
| NAPS 20214 | 265 adults without heart disease | 2,000 FU/day, median 3 years | No effect on blood pressure |
Why the Results Differ
The positive trials were short (8 weeks) and enrolled people whose blood pressure was already high12. The NAPS trial lasted about 3 years and enrolled healthy older adults at low risk of heart disease4. It’s possible nattokinase has a small short-term effect in people with raised blood pressure that doesn’t show up in a general population or over longer periods, but that hasn’t been tested directly.
How Might Nattokinase Lower Blood Pressure?
In the 2008 trial, renin activity, a hormone involved in blood pressure control, fell more on nattokinase than on placebo1. In the 2016 trial, von Willebrand factor, a clotting protein, showed a downward trend in women2. These are possible explanations rather than proven mechanisms.
How Does It Compare With Other Supplements?
The effect is in the same small range as some other supplements. For example, pomegranate lowered blood pressure by about 8/3 mmHg in a meta-analysis of 22 trials6; see our guide to pomegranate benefits. None of these replace lifestyle changes or medicine when you need them.
Our Top Nattokinase Pick
Nutricost Nattokinase 2,000 FU
2,000 FU1 capsule a day120 servings
The blood pressure trials used 2,000 FU a day, and Nutricost gives that in one capsule, so you can try the studied dose for 8 weeks and track your readings. It’s the #1 pick in our guide to the best nattokinase supplements. It hasn’t been tested in its own clinical trial, and it isn’t suitable if you take aspirin or a blood thinner.
Can You Take Nattokinase With Blood Pressure Medicine?
We didn’t find reports of a direct interaction, but if nattokinase lowers blood pressure even slightly, the effects could add up. More importantly, nattokinase affects clotting7, and MSK advises people taking blood thinners or daily aspirin not to use it5. If you take aspirin or another blood thinner for your heart, check your full medicine list with your doctor or pharmacist. See our guides to nattokinase and blood thinners and nattokinase side effects.
If You Want to Try It
- Talk to your doctor first, especially if you take any blood pressure medicine or aspirin.
- Use the studied dose: 2,000 FU once a day14. See our guide to nattokinase dosage.
- Measure your blood pressure at home for a week before you start and again after 8 weeks, at the same time of day.
- Don’t stop or change your blood pressure medicine on your own.
For a broader look at what nattokinase can and can’t do, see our guide to nattokinase benefits.
Final Verdict
Nattokinase may lower blood pressure by a few points in short trials, about 3–6 mmHg systolic, but the longest and largest trial found no effect over 3 years. It’s not a dependable treatment for high blood pressure, and it carries a bleeding risk for people on aspirin or blood thinners.
If your doctor agrees and you’d like to try it, use the studied 2,000 FU dose, such as Nutricost Nattokinase 2,000 FU, and track your readings. Compare all 7 picks in our guide to the best nattokinase supplements.
Important: This guide is for general information and isn’t medical advice. Don’t stop or change blood pressure medicine without talking to your doctor. Nattokinase isn’t suitable if you take blood thinners or daily aspirin.
Frequently Asked Questions
Does nattokinase lower blood pressure?
How much does nattokinase lower blood pressure?
How long does nattokinase take to lower blood pressure?
How much nattokinase should I take for blood pressure?
Can I take nattokinase with blood pressure medication?
Ask your doctor first. The effects could add up, and nattokinase isn’t advised for people who also take aspirin or blood thinners5.
Can nattokinase replace blood pressure medicine?
No. The effect is small and inconsistent, and the longest trial found no benefit4.
Sources & History
References
- Effects of Nattokinase on Blood Pressure: A Randomized, Controlled Trial — Hypertension Research, 2008
- Consumption of Nattokinase Is Associated With Reduced Blood Pressure and von Willebrand Factor: Results From a Randomized, Double-Blind, Placebo-Controlled, Multicenter North American Clinical Trial — Integrated Blood Pressure Control, 2016
- Nattokinase Supplementation and Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Randomized Controlled Trials — Reviews in Cardiovascular Medicine, 2023
- Nattokinase Atherothrombotic Prevention Study: A Randomized Controlled Trial — Clinical Hemorheology and Microcirculation, 2021
- Nattokinase — Memorial Sloan Kettering Cancer Center, About Herbs, 2025
- The Effects of Pomegranate Consumption on Blood Pressure in Adults: A Systematic Review and Meta-Analysis — Phytotherapy Research, 2024
- The Effects of Nattokinase Supplementation on Collagen-Epinephrine Closure Time, Prothrombin Time and Activated Partial Thromboplastin Time in Nondiabetic and Hypercholesterolemic Subjects — Food & Function, 2019
Update history
- Rewritten with a table of all blood pressure trials, the 3-year NAPS result, possible mechanisms, interaction and bleeding guidance, and how to track your own readings.
