Growth Hormone Secretagogue
A compound that stimulates the secretion of growth hormone from the pituitary gland. Growth hormone secretagogues include GHRH receptor agonists such as tesamorelin and ghrelin receptor agonists such as the research peptides GHRP-2, GHRP-6, and ipamorelin.
Technical Context
GHS are classified by mechanism: GHRH receptor agonists (tesamorelin, CJC-1295/Mod GRF 1-29) stimulate GH release via the GHRH pathway on pituitary somatotrophs, while ghrelin receptor (GHS-R1a) agonists (GHRP-2, GHRP-6, ipamorelin, hexarelin, MK-677/ibutamoren) mimic ghrelin's action through a distinct pathway. The two pathways are synergistic — combining GHRH and ghrelin receptor stimulation produces greater GH release than either alone. Tesamorelin is the only approved GHS. Research GHS are widely discussed in online peptide communities, though their long-term safety profiles in humans are not established through adequate clinical trials. Some GHRPs also affect cortisol, prolactin, and appetite (notably GHRP-6 increases hunger).