hGH is a polypeptide hormone ( a long chain of 191 amino acids) Normally it is secreted by the anterior pituitary gland(this gand lies at the base of the brain). Somatropin refers to growth hormone of the same amino acid sequence as the naturally ocurring growth hormone. Somatropin is extracted from the human pituitary gand and was designated hGH. Manufactured growth hormone is made by recombinant DNA technology. The proper addreviation is rGH. It was discovered that adults that were defiecent in rGH suffered from premature cardiovascular disease, reduced bone density, central obesity, decreased muscle mass, depressed mood, elevated leve of LDL, slower wound healing, fatigue, poor excercise tolerance and poor immune function. Using rGH or hGH is to believe to slow down, or reverse some or all of this process.