EPO, Ephoetin alfa, is a hormone that stimulates the production of red blood cells in the body. Synonyms for EPO include erythropoietin, epoetin, and EPO alfa. The drug is widely used in the medical field to treat conditions such as anemia, kidney disease, and cancer. Additionally, EPO is a popular performance-enhancing drug among athletes due to its ability to enhance endurance and improve oxygen delivery. As a result, EPO is frequently referred to as blood doping, which is illegal in competitive sports. While EPO has legitimate medical uses, its misuse can have detrimental consequences, including the risk of blood clots, stroke, and heart attack.