Erythropoietic effects of low‐dose cobalt application

Cobaltous ions (Co²⁺) stabilize HIFα, increase endogenous erythropoietin (EPO) production, and may, therefore, be used as performance‐enhancing substance. To date, the dosage necessary to stimulate erythropoiesis is unknown. The aim of this study was, therefore, to determine the minimum dosage necessary to increase erythropoietic processes. In a first double‐blind placebo‐controlled study (n=5), single oral Co²⁺ dosages of 5 mg (n=6) and 10 mg (n=7) were administered to healthy young men. Cubital venous blood and urine samples were collected before and up to 24 h after Co²⁺ administration. In a second study, the same daily Co²⁺ dosages were administered for 5 days (placebo: n=5, 5 mg: n=9, 10 mg: n=7). Blood and urine samples were taken the day before administration and at day 3 and day 5. Plasma [EPO] was elevated by 20.5±16.9% at 5 h after the single 5 mg administration (p