EPO is also referred to as Epoetin or Erythropoietin. While this substance is naturally produced in the body and it can also be made by recombinant DNA technology. It is pharmacologically classified as a haematopoietic growth factor which means it promotes the growth of red blood cells in the body. Red blood cells carry oxygen through the body. EPO is used clinically in the management of anaemia associated with chronic renal failure in dialysis and predialysis patients, in conjunction with other treatments for HIV and as a part of a drug-treatment regime for those undergoing chemotherapy.

The abuse of EPO by athletes can have particularly serious consequences as it use can result in changes in thickness of the blood thus affecting the rate at which blood flows through the body. This can be further exacerbated by dehydration potentially leading to a life-threatening situation for the athlete.

According to the WADA 2004 code EPO is prohibited and "unless the Athlete can demonstrate that the concentration was due to a physiological or pathological condition, a Sample will be deemed to contain a Prohibited Substance where the concentration of the Prohibited Substance or its metabolite and/or relevant ratios or markers in the Athlete s Sample so exceeds the range of values normally found in humans so as not to be consistent with normal endogenous production. The presence of analogues mimetics, diagnostics marker(s) or releasing factors of the hormone or any other finding which indicate(s) that the substance detected is not the naturally present hormone, will be reported as an adverse analytical finding."

`references` Sources

Martindale

The Merck Manual

WADA 2004 List of Prohibited Substances.