Nattokinase is a fibrinolytic enzyme extracted from natto, a traditional Japanese food made by fermenting soybeans with *Bacillus subtilis natto* bacteria. It is best known for supporting healthy blood flow and healthy fibrin metabolism, and its potency is measured in Fibrinolytic Units (FU).

FU stands for Fibrinolytic Units — a standardized measure of nattokinase enzyme activity per serving. Higher FU means higher enzyme potency. Great Billiom Nattokinase delivers 10,800 FU per 2-capsule serving, the same amount used in the 2022 Chen study of 1,062 participants.

10,800 FU is the daily dose used in the landmark Chen et al. 2022 study published in *Frontiers in Cardiovascular Medicine*. Researchers followed 1,062 participants over 12 months and tracked outcomes using blood lipid panels and carotid artery ultrasound. Lower doses (typically 2,000 to 4,000 FU) were not part of the effective-dose findings of this study, which is why Great Billiom formulates at the full 10,800 FU per serving.

Published research on nattokinase has examined effects on both systolic and diastolic blood pressure, with some studies observing modest reductions in participants with mildly elevated blood pressure. Great Billiom Nattokinase is formulated at the 10,800 FU dose used in published research. If you are taking medication for blood pressure, speak with your healthcare professional before adding nattokinase to your routine.

The Chen et al. 2022 study measured changes in carotid artery intima-media thickness (a common measure of arterial wall health) over 12 months in 1,062 participants taking 10,800 FU daily. Researchers observed favorable changes in the treatment group. While individual results vary, this is the published dose Great Billiom's formula is built around. Nattokinase is not a treatment for atherosclerosis — it is a dietary supplement that supports everyday arterial wellness.

Nattokinase is classified as a fibrinolytic enzyme, meaning it supports the breakdown of fibrin — the protein that forms the structural mesh of blood clots. It should not be considered a replacement for medical treatment of diagnosed clotting disorders. For everyday healthy-fibrin and circulation support, daily use at a research-backed dose is the approach most supplement users take.

Nattokinase is often described online as a "natural blood thinner," though it is more accurately described as a fibrinolytic enzyme that supports healthy blood viscosity and fibrin metabolism. It is not a substitute for prescription anticoagulant medication. If you are on warfarin, aspirin, Eliquis, Plavix, or any prescription medication affecting blood, speak with your healthcare professional before taking nattokinase.

Yes, nattokinase is generally well-tolerated for daily use at recommended dosages. For Great Billiom Nattokinase, the recommended use is 2 delayed-release vegetarian capsules daily on an empty stomach. The Chen study observed no noticeable adverse effects over 12 months of daily 10,800 FU use. Consult your healthcare professional before starting, especially if you take prescription medication or have a medical condition.

For best absorption, take nattokinase on an empty stomach — at least 1 hour before a meal or 2 hours after a meal. Many users prefer to take their daily serving before bedtime for uninterrupted overnight absorption. The delayed-release capsule design supports targeted delivery past the stomach acid.

Vitamin K2 MK-7 (menaquinone-7) activates proteins — including matrix Gla protein and osteocalcin — that help direct calcium to bones and away from arterial walls. The Chen 2022 study co-administered K2 MK-7 at 180 mcg to a subgroup of 181 participants, making it the only nattokinase-plus-K2 dose pairing backed by large published research. Some online articles claim K2 and nattokinase "cancel each other out" — this is a misconception. The Chen study specifically demonstrated they work synergistically at these doses.

Serrapeptase (also called serratiopeptidase) is a proteolytic enzyme used in systemic enzyme therapy for decades. Combined with nattokinase, it adds a second enzyme-based mechanism for supporting circulatory and physical wellness. Nattokinase-plus-serrapeptase is one of the most-searched combination supplements for adults focused on long-term cardiovascular health.

Aspirin is an FDA-approved medication that inhibits platelet aggregation; nattokinase is a dietary supplement enzyme that supports healthy fibrin metabolism. They work through different mechanisms. Nattokinase should not be considered a replacement for prescription aspirin if your doctor has prescribed it. For adults not on prescribed antiplatelet therapy, nattokinase is a research-backed enzyme-based option for daily cardiovascular wellness.

Nattokinase is not recommended for people who are pregnant or nursing, children, those preparing for surgery (stop at least 2 weeks before), or anyone taking prescription anticoagulants, antiplatelet medications, or blood pressure medications — without consulting a healthcare professional first. If you have a medical condition or take daily medication, your doctor should review any new supplement.

Yes. Great Billiom Nattokinase is manufactured in a GMP-certified facility, third-party lab tested for identity, potency, purity, heavy metals, and microbial safety, and is non-GMO and gluten-free. The capsules are HPMC delayed-release vegetarian capsules — no gelatin. The product contains soy (declared per FDA requirements) because nattokinase is derived from fermented soybeans.