Human growth hormone (GH) increases estimates of whole body protein synthesis, but has little effect on the rates of proteolysis either post-absorptively or when absorption occurs during a meal. In contrast to insulin, GH stimulates protein synthesis in skeletal muscle tissue. Prednisone in high doses induces protein catabolism and has been used as a controlled model for catabolic illness. Prednisone increases the rates of proteolysis and amino acid oxidation, but has little effect on estimates of protein synthesis. The administration of high doses of GH together with prednisone prevents the protein catabolic effects of prednisone alone. Thus, GH may provide a new management strategy in patients with significant protein catabolic conditions.