Used as an anticoagulant in medical treatments to prevent blood clotting. It is particularly effective in patients with heparin-induced thrombocytopenia (HIT), where traditional anticoagulants like heparin cannot be used due to adverse reactions. Recombinant hirudin directly inhibits thrombin, a key enzyme in the blood clotting process, making it valuable in surgeries and treatments requiring precise control of clotting. Additionally, it is employed in research to study blood coagulation mechanisms and develop new therapeutic strategies for cardiovascular diseases.