Epoetin injection is a synthetic form of erythropoietin (EPO). EPO is naturally created in the body, mostly by the kidneys. It increases the production of red blood cells in the bone marrow. Severe anemia can result if the body does not create enough EPO. This is common in people with chronic kidney disease whose kidneys are failing. Epoetin may also be used to prevent or treat anemia induced by surgery or other medications used to treat other illnesses such as HIV or cancer. The side effects that occur most often include high blood pressure, swelling, fever, dizziness, nausea, and pain at the site of the injection.