Identification and measurement of epitestosterone in the sulfate fraction of plasma of normal men

Abstract Epitestesterone was identified in the sulfate fraction (EpiT S) from pooled plasma collected from U normal adult men. The concentration of EpiT S (0.42 μg/100 ml) was 3 times higher than that of testosterone sulfate (TS) (0.12 μg/100 ml) identified in the same sample, and was about at the same level than free testosterone (T) (O.47 μg/100 ml). The free epitestosterone (EpiT) was not found: this compound was present in concentrations less than 0.03 μg/100 ml of plasma.