Prostaglandins (PG) are a group of lipid compounds with hormone-like effects that exhibit diverse physiological activities in animals. PG are enzymatically derived from fatty acids with 20 carbon atoms and a 5-carbon ring. They belong to a subfamily of eicosanoids and prostanoid class of fatty acid derivatives. PG have two main derivatives: prostacyclin and thromboxane. Prostacyclin is a potent local vasodilator and inhibitor of blood platelet aggregation.