To minimize the chances of being caught after doping with recombinant human erythropoietins (rhEPO), athletes have turned to new practices using micro-doses and excess fluid ingestion to accelerate elimination and decrease the probability of detection. Our objective was to test the sensitivity of detection by validated methods (IEF: isoelectric focusing; SDS-PAGE: sodium dodecyl sulfate polyacrylamide gel electrophoresis) when such practices are used. First, after a three-week rhEPO boost period and 10?days of wash out, detection of a single 900?IU micro-dose of Eprex? was evaluated in healthy male subjects. After an injection in the evening, urine and plasma samples were collected the following morning. Half of the subjects then drank a bolus of water and new samples were collected 80?min later. Interestingly, rhEPO was detected in 100% of the samples even after water ingestion. A second similar protocol was then performed with a single injection of a micro-dose of rhEPO (500?IU or 900?IU), without a prior rhEPO boost. In addition, urine and plasma samples were also collected 15 and 20?h post rhEPO administration. Once again drinking water did not affect the rate of detection. Urine appeared a better matrix to detect micro-doses after 10?h, enabling between 92% and 100% of identification at that time. The rate of identification decreased rapidly thereafter, in particular for the 500?IU micro-dose. However IEF analysis still resulted in 71% identification of rhEPO in urine after 20?h. These results could help to define a better strategy for controlling and identifying athletes using rhEPO micro-doses. Copyright ? 2016 John Wiley & Sons, Ltd.