Nattokinase
A fibrinolytic enzyme from fermented soybeans (natto). The best-supported effect is a modest blood-pressure reduction; the virally spread claim that nattokinase dissolves arterial plaque rests on weak (retrospective) evidence — the highest-quality RCT found no effect on atherosclerosis.
How it works
Nattokinase is an enzyme produced when soybeans are fermented into natto by the bacterium Bacillus subtilis var. natto. In the test tube it cleaves fibrin — the mesh protein that holds blood clots together — and also stimulates the body's own clot-clearing system (tPA). In humans, the most consistent effect is a mild blood-pressure reduction, probably via ACE inhibition. That it dissolves arterial plaque is not supported by high-quality studies.
Dosage
What matters is not the milligram count but the enzyme activity in FU (fibrinolytic units). Preventively, ~2,000 FU/day is common; trials with cardiovascular endpoints used higher doses (up to 10,800 FU/day). Take on an empty stomach (~30–60 min before or 2 h after a meal) so the enzyme isn't broken down as a dietary protein.
Considerations
What's established: an RCT meta-analysis (6 randomized trials) shows a modest blood-pressure reduction (~−3.5/−2.3 mmHg) — the most robust finding. What's not established: the virally cited Chinese study of 1,062 participants (Chen 2022) reporting up to 36% plaque regression was retrospective and had no true placebo/control group (the 'control' merely took a lower dose) — it cannot prove cause and effect. The highest-quality evidence, the randomized, placebo-controlled NAPS trial (Hodis 2021, 265 participants, 3 years), found no difference in intima-media thickness or arterial stiffness. For blood lipids the RCT picture is mixed-to-unfavorable. Claims about degrading viral 'spike proteins' come from test-tube experiments with no human evidence. IMPORTANT SAFETY: nattokinase affects blood clotting. Anyone on blood thinners (warfarin, apixaban, rivaroxaban, high-dose aspirin) or with a clotting disorder must only use it after medical consultation — otherwise dangerous bleeding can occur. Not a substitute for statins or other proven cardiovascular therapy. Bottom line: interesting for blood pressure, overrated on the plaque promise.
