Product Name: Hirudin Extract Powder Spec:80,000AT-U,100,000AT-U,etc.Function: Use Hirudin is the most potent natural inhibitor of thrombin.Unlike antithrombin III, hirudin binds to and inhibits only the activity of thrombin, with a specific activity on fibrinogen. Therefore, hirudin prevents or dissolves the formation of clots and thrombi..