Most commonly, 100 mg (2,000 fibrinolytic units (FU)) of nattokinase are taken by mouth daily.^[1][2][3][4] This dose is reported to not cause adverse effects by the European Food Safety Authority (EFSA).^[5] Limited research using higher doses of nattokinase also reported no adverse effects. People living in China have taken 540 mg (10,800 FU) of nattokinase daily for a year,^[6] and adults living in the United States have taken 552 mg of nattokinase daily for four weeks^[2] without any reported adverse effects. Nattō itself can be used, and some anti-clotting effects have been noted with 12 grams of nattō daily over 2 weeks.^[7]