How is HGH released in your body
HGH is secreted from the pituitary in a pulsatile fashion, generally following a circadian rhythm. A number of stimuli can initiate an HGH secretion, the most powerful being short duration, high intensity exercise and sleep. During the first few hours of sleep (deep sleep stages), Somatostatin is turned off and GHRH is turned on, resulting in HGH bursts.
HGH secretion is stimulated by Growth Hormone Releasing Hormone (GHRH) which is produced by the hypothalamus. HGH, and IGF-1 create a negative feedback loop, meaning when their levels are high, it blunts release of GHRH, which in turn blunts the release of more HGH.
Somatostatin (SS), secreted by the hypothalamus as well as other tissues inhibits the secretion of HGH Somatostatin in response to GHRH and to other stimulatory factors such as low blood glucose concentration. High levels of IGF-1 also stimulate Somatostatin secretion.
Ghrelin is a peptide hormone secreted from the stomach. Ghrelin binds to receptors on somatotrophs and potently stimulates secretion of growth hormone. Ghrelin, as the stimulator for the growth hormone secretagogue receptor, potently stimulates secretion of growth hormone. The ghrelin signal is integrated with that of growth hormone releasing hormone and somatostatin to control the timing and magnitude of growth hormone secretion.
Once HGH is released, it is very short lived. It is generally metabolized and gone within a half-hour. During this half-hour, it travels to the liver and other tissues and induces them to secrete a polypeptide hormone called Insulin-like Growth Factor One (IGF-1).
