Italian cyclist Fabio Taborre was one of the two professional cyclists who tested positive for the EPO-stimulating drug roxadustat in 2015, when the drug was still only in its early phase III clinical trials. — Wikimedia Commons
Life-saving treatment on one hand, performance-enhancing drug on the other – erythropoietin, also known as EPO, is a classic example of how one substance can be used for both good and bad purposes.
For chronic kidney disease patients suffering from anaemia, the synthetic version produced via recombinant DNA technology is a life-saving hormone that replaces the natural EPO, which is no longer being adequately produced by their failing kidneys.