Beating the EPO Blood Doping Test

Synthetic erythropoietin, called EPO, was widely used by endurance athletes in the 1990s to boost red blood cell production and blood oxygen carrying capacity. The use of EPO declined after 2000 when the World Anti-Doping Agency (WADA) developed a test to detect EPO in urine.

But now, WADA believes that athletes could be beating the current EPO urine tests by “microdosing” – injecting very small (micro) doses of EPO at night. EPO is excreted so rapidly into the urine that most of an injected dose will be eliminated from the body within eight hours. Thus, microdosing is likely to go undetected as long as urine samples are not demanded in the middle of the night.

Microdosing works because the effects of the erythropoietin outlast the hormone itself. Researchers now know that even such small, intermittent doses of EPO will boost the body’s production of red blood cells significantly over time. They aren’t publishing their dosage information to avoid providing a recipe for blood-doping, but they suspect that athletes already know.