Nattokinase

4 studies · 3 supporting · 1 against

Nattokinase is an enzyme extracted from natto (fermented soybeans) that breaks down fibrin and is thought to reduce blood viscosity and modestly suppress renin activity, which can lower blood pressure.

Dose: 2000 mg

Tested as: Nattokinase 2,000 FU/day (approx. 100 mg NSK-SD softgel) in the primary RCT — note FU (fibrinolytic units) is not mg; potency varies by manufacturer and is not interchangeable across brands. Pooled meta-analysis trials used doses in a similar range.

2 studies · 0 supporting · 2 against

How it was tested: Low-dose nattokinase increased total cholesterol (MD +5.27, p<0.00001) and decreased HDL-C (MD -2.76, p<0.00001) vs placebo; high-dose nattokinase also increased total cholesterol (MD +3.18, p<0.00001); no significant effect on triglycerides

Nattokinase's proposed cardiovascular actions (reducing fibrin, blood viscosity, mild renin suppression) do not target LDL production or clearance pathways, which may explain why it does not move cholesterol numbers on its own.

Dose: 1200–4000 mg

Tested as: Nattokinase 1,200-4,000 FU/day tested alone in pooled trials — note FU (fibrinolytic units) is not mg. A separate trial tested 2,500 FU/day combined with 7 mg lovastatin-equivalent from red yeast rice (Monascus), not nattokinase alone.