What is heparin injection? Heparin is an anticoagulant (blood thinner) that prevents the formation of blood clots. Heparin is used to treat and prevent blood clots in the veins, arteries, or lung. It is also used before surgery to reduce the risk of blood clots.
Heparin works by inactivating thrombin in the clotting process. This stops the formation of fibrin and so stops blood clots forming. Heparin is used to treat blood clots that have formed abnormally inside the blood vessels. It can also be used to prevent these types of dangerous blood clots.