Deadly snake venom can be turned into life-saving therapeutics. Currently, several medicinal agents approved by the US Food and Drug Administration originated from snake venom. These include captopril, used to treat high blood pressure, as well as eptifibatide and tirofiban, used as bloodthinning agents to prevent thrombosis (clotting of blood in the circulation). Many other snake venom toxins have also been made into reagents that help to diagnose different kinds of blood disorders. Here, we discuss the molecular basis of how snake venom affects components in blood to unveil secrets behind the deadly weapon that can be harnessed for its power of healing.