Dr. Bill Evans | Running Performance & Athletic Development on Instagram: "EPO is a PED that increases RBC content. It’s produced naturally under low partial pressures of oxygen, like during training. However, when introduced in high doses, RBC content increases drastically and so too does performance. It was all the rage in the 90s, but got banned. A recent paper showed it might still be in use with changes in performance metrics across the board from micro-dosing (smaller more frequent doses).