<b>Six weeks of oral <i>Echinacea purpurea</i> supplementation does not enhance the production of serum erythropoietin or erythropoietic status in recreationally active males with above average aerobic fitness</b>.

The purpose of this study was to investigate the effect of six weeks of oral <i>Echinacea purpurea</i> supplementation on serum erythropoietin (EPO) and erythropoietic status. Twenty-four males (mean ± SE): age = 25.2 ± 1.4 yr, height = 178.1 ± 1.4 cm, body mass = 78.1 ± 1.6 kg, body fat = 12.7 ± 0.9 %, VO_2max = 52.9 ± 0.9 mL·kg^-1·min^-1 were randomly grouped using a matched-pair, double-blind design and self-administered 8,000 mg·d^-1 of either <i>Echinacea purpurea</i> (ECH) (<i>n</i> = 12) or placebo (PLA) (<i>n</i> = 12) for 42 consecutive days. Blood samples were collected prior to supplementation (day-0) and every two weeks during the supplementation period (day-14, -28, and -42) and were analyzed for EPO, red blood cell count, hemoglobin concentration, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin concentration. Separate 2 × 4 (Group × Time) factorial ANOVA with repeated measures on time were used to determine statistical differences with significance set at <i>p</i> ≤ 0.05. There were no significant interaction, group, or time effects observed for EPO or erythropoietic status markers for any of the measurement points (<i>p</i> ≤ 0.05). The present study indicated that six weeks of oral ECH supplementation in recreationally active males with above average aerobic fitness did not enhance EPO or erythropoietic status. These findings are in contrast with previous reports of ECH supplementation in untrained participants with average fitness levels, but consistent with observations in trained endurance athletes.