What Is Growth Hormone Releasing Hormone (GHRH)?
Growth hormone releasing hormone (GHRH) is a naturally occurring peptide released by nerves, called arcuate neurons, in the hypothalamus. The peptide travels from the hypothalamus to the pituitary gland where it binds to the growth hormone releasing hormone receptor and causes the release of growth hormone (GH). GHRH is critical for proper growth and development, increasing lean body mass and reducing adiposity (fat tissue). GHRH is indirectly responsible for muscle growth and long bone growth, but has also been found to regulate inflammation, mitigate pain, and play an important role in the sleep-wake (diurnal cycle). It is released in a pulsatile manner from the hypothalamus and thus causes the pulsatile release of GH as well. This pattern of release is important to the function of growth hormone and thus to physiology in general.
GHRH Analogs Are Common
A number of analogues of GHRH have been developed in an effort to target some of the peptide’s effects while avoiding other properties. Alterations have also been made in order to to prolong the half-life of exogenously administered GHRH. Examples of GHRH analogues include CJC-1295, Sermorelin, and Tesamorelin. Tesamorelin was approved by the FDA in 2010 for the treatment of lipodystrophy (abnormal deposition of fat) in HIV.