Secretagogue
Definition
A secretagogue is a substance that stimulates the secretion of another substance. In peptide research, the term most commonly refers to growth hormone secretagogues (GHS) — compounds that stimulate growth hormone release from the anterior pituitary gland, typically by binding the GHSR (ghrelin receptor).
Types of Growth Hormone Secretagogues
GH secretagogues fall into several categories:
- GHRH analogues — Sermorelin, CJC-1295 (with and without DAC), tesamorelin. These bind the GHRH receptor and stimulate GH release through the natural GHRH pathway
- Ghrelin mimetics / GHRPs — GHRP-6, GHRP-2, hexarelin, ipamorelin. These bind GHSR-1a (the ghrelin receptor) and amplify GH pulses through a complementary mechanism to GHRH
- Non-peptide secretagogues — MK-677 (ibutamoren) is an oral GH secretagogue that binds GHSR-1a but is a small molecule rather than a peptide
Mechanism and Synergy
GHRH and ghrelin/GHRP pathways are synergistic — they activate GH release through different intracellular signalling cascades (cAMP/PKA vs. IP3/calcium). Research protocols sometimes combine GHRH analogues with GHRPs to exploit this synergy. Both pathways maintain GH pulsatility, unlike exogenous GH administration which provides a non-physiological continuous elevation.
Beyond Growth Hormone
While “secretagogue” is most associated with GH, the term applies broadly. Insulin secretagogues (sulfonylureas, incretins) stimulate insulin release, and gastric acid secretagogues stimulate stomach acid production.
Related Peptides
Peptide profiles that reference “Secretagogue” in their research content.