Hennigar SR, Berryman CE, Harris MN, et al. - In this 3-phase, randomized, double-blind, placebo-controlled trial involving 50 healthy young males, researchers ascertained if testosterone supplementation during energy deficit increased indicators of iron turnover and attenuated the decline in erythropoiesis vs placebo. The investigation was carried out at the Pennington Biomedical Research Center. According to findings, hepcidin decreased by 41%, indicators of iron turnover increased, and functional iron stores were decreased with testosterone administration during energy deficit vs placebo. Such outcomes show that testosterone suppresses hepcidin to increase iron turnover and maintain erythropoiesis during severe energy deficit through either direct or indirect mechanisms.