Erythropoietin (EPO) is a naturally occurring protein hormone produced by cells in the kidneys. These cells are sensitive to the oxygen concentration in the blood, and release increased EPO when the oxygen concentration is low.
EPO is commonly marketed under the brand names Procrit and Epogen in the US, Eprex and NeoRecormon in Europe and elsewhere. Synthetic (recombinant) EPO is frequently prescribed to patients who are receiving kidney dialysis, since natural production is inhibited by both the disease and the dialysis.
In cases of blood loss resulting in severe anemia, that involve those who for religious reasons do not accept blood or blood products, Hospital Liaison Committee members (there are currently about 850 of these committees worldwide) are available with information and current medical literature for physicians, showing the efficacy of recombinant erythropoietin (EPO) in increased production of red blood cells. This synthetic hormone acts like the natural erythropoietin found in our kidneys and stimulates the bone marrow to send new, fresh red cells into the bloodstream.
While recombinant erythropoietin itself is not a blood product, some brands of the synthetic form do contain a very small amount of albumin, which is a minor blood fraction. Epogen and Procrit contain 2.5 mg human serum albumin, which prevents the drug from sticking to the vial, and acts as a carrier molecule to help the EPO remain in the bloodstream until it reaches its destination at the bone marrow.