A growth hormone secretagogue is any compound that prompts the pituitary to release its own growth hormone rather than supplying the hormone from outside. The category is mechanistic, not structural, and spans three groups.
The three groups
- GHRH receptor agonists — GHRH analogs such as sermorelin, Mod GRF 1-29 and tesamorelin, acting on GHRHR
- Ghrelin receptor agonists — the GHRPs, acting on GHS-R1a
- Non-peptide GHS-R1a agonists — orally active small molecules such as ibutamoren (MK-677)
How this differs from exogenous growth hormone
Recombinant human growth hormone is a prescription-only biologic that supplies the hormone directly and overrides normal pulsatility. Secretagogues act upstream on somatotrophs, so the resulting release stays pulsatile and remains subject to negative feedback from somatostatin and IGF-1. That feedback ceiling is the defining mechanistic feature of the class, and it is why studies often pair a GHRH analog with a GHRP to engage both receptors.
Related terms
research use only. Browse growth hormone and performance peptides, or read the muscle growth research overview.