Erythropoietin is a type of protein called a growth factor. There are different types; epoetin alfa, beta, zeta, theta (Eprex®, NeoRecormon®) and darbepoetin alfa (Aranesp®). People often call them EPO for short.
It stimulates the bone marrow to make red blood cells. The bone marrow is a spongy material inside the bones where all of our blood cells are made.
Erythropoietin is made naturally in the body. But it can be made outside the body and used as a treatment for anaemia. Anaemia means having too few red blood cells.
Red blood cells carry oxygen around the body. If the number of red blood cells in your blood is low, you may be very tired and feel you have no energy. You may also become breathless.
Many people with cancer will develop anaemia at some time during their illness. Anaemia can also be caused by treatment with chemotherapy. Doctors sometimes use erythropoietin to treat anaemia instead of giving you a blood transfusion or if you cannot have a blood transfusion.