Somatotropin, also commonly referred to as human growth hormone (HGH), is a hormone that is produced in the human body and excreted into the blood by the somatotrope cells of the anterior pituitary gland. It is a single-chain protein that is composed of 191 amino acids with a molecular weight of approximately 22,000 Daltons. GH secretion has many direct and indirect effects on the human body. HGH stimulates the liver’s production of insulin-like growth factor (Igetropin IGF-1 L3). Because GH stimulates the liver’s production of IGF-1, the effects of both GH and IGF-1 are same. Synthetic version of Human Growth Hormone manufactured by Hygene is called Hygetropin (191 amino acid sequence growth hormone).