Human Growth Hormone Growth hormone is a small protein that is made by the pituitary gland and discharge into the bloodstream. Growth hormone manufacture is controlled by a compound set of hormones produced in the hypothalamus of the brain and in the intestinal tract and pancreas. The pituitary gland puts out growth hormone in burst open; levels rise following exercise, trauma, and sleep. Under normal conditions, more growth hormone is produced at night than during the day. This physiology is multiplex, but at a minimum, it tells us that sporadic blood tests to measure growth hormone levels are meaningless since high and low levels alternate throughout the day. But scientists who carefully measure overall growth hormone production report that it rises during childhood, peaks during puberty, and declines from middle age onward. Growth hormone acts on many tissues throughout the body. In children and teenage, it restorative the growth of bone and cartilage. In people of