Somatotropin, also called Growth hormone, is a protein-based polypeptide which contained 191 amino acids. It is produced and secreted by the somatotroph cells of the anterior pituitary gland. Somatotropin acts by stimulating the release of another hormone called somatomedin by the liver, thereby causing growth. Somatotropin is also known as somatropin.
Somatotropin stimulates body growth generally, specially the lengthening of long bones in particular. Whereas anabolic steroids act primarily on muscles, somatotropin, or human growth hormone, strengthens bones and tendons as well. It is used clinically to treat children's growth disorders and adult growth hormone deficiency. In recent years, replacement therapies with human growth hormones (hGH) have become popular in the battle against aging and weight management. Reported effects on GH deficient patients (but not on healthy people) include decreased body fat, increased muscle mass, increased bone density, increased energy levels, improved skin tone and texture, increased sexual function and improved immune system function. At this time hGH is still considered a very complex hormone and many of its functions are still unknown.
In its role as an anabolic agent, somatotropin has been used by competitors in sports since the 1970s, and it has been banned by the IOC and NCAA. Traditional urine analysis could not detect doping with hGH, so the ban was unenforceable until the early 2000s, when blood tests that could distinguish between natural and artificial hGH were starting to be developed. Blood tests conducted by WADA at the 2004 Olympic Games in Athens, Greece primarily targeted hGH.