The History of Warfarin and its Evolution as an Anticoagulant

American dairy farmers in the 1920s noted cows bleeding due to moldy sweet clover hay, leading to the identification of the compound dichromal that inhibits clotting. Warfarin, a potent variant of dichromal, was originally developed as a rat poison but later found safe in humans under the name coumadin. Despite initial reluctance due to its rat poison association, Warfarin gained popularity after President Eisenhower's successful treatment with it. Today, Warfarin remains widely used globally, along with newer anticoagulants.