Growth hormone (GH or GH-N) is also known as Somatotropin, Pituitary growth hormone. GH belongs to the somatotropin/prolactin family. Growth hormone (GH) may form monomer, dimer, trimer, tetramer and pentamer, by disulfide-linked or non-covalently associated, in homopolymeric and heteropolymeric combinations. GH can also form a complex either with GHBP or with the alpha2-macroglobulin complex. Growth hormone (GH) plays an important role in growth control. Its major role in stimulating body growth is to stimulate the liver and other tissues to secrete IGF-1. It stimulates both the differentiation and proliferation of myoblasts. It also stimulates amino acid uptake and protein synthesis in muscle and other tissues.