Thrombolysis Nattokinase can dissolve thrombus directly. The thrombolytic effect of wet natto per gram would be the equivalent of 1600IU urokinase. Its time of effect on the thrombus up to 8-12 hours, but urokinase has only 30 minutes. Urokinase only as an injection, But Nattokinase can be injected or taken orally, and play a role in capillary. Natto as a safety edible thrombus preventive, has been eaten in Japan for 1000 years.