"Administration of HGH induces a rise in circulating IGF-1 that stimulates glucose and amino acid uptake in muscle, which improves muscle protein synthesis. ... The metabolic effects of HGH are, in part, mediated through IGF-1 produced in the liver and in the peripheral tissues influenced by HGH"
"Steroidogenic enzymes are expressed in human sebaceous glands where they may play a role in local androgen production. Also, IGF-1 can induce 5α-reductase in human skin fibroblasts, leading to an increased conversion of testosterone to DHT."