Definition
Any compound that stimulates the pituitary to release growth hormone, via the GHRH or ghrelin receptor.
A growth hormone secretagogue is any compound that causes the pituitary to secrete growth hormone. In peptide research the term covers two classes. GHRH analogues, including sermorelin, CJC-1295 and tesamorelin, act on the GHRH receptor. Ghrelin-receptor agonists, including GHRP-2, GHRP-6, hexarelin and ipamorelin, act on GHS-R1a. Because the receptors use different signalling pathways, combined stimulation has been reported to produce greater growth hormone release than either class alone. Non-peptide secretagogues also exist, such as macimorelin, an approved oral diagnostic agent. Most secretagogues appear on the WADA Prohibited List under S2.