Growth Hormone Secretagogue

A growth hormone secretagogue is any compound that causes the pituitary to release growth hormone. The name is functional, not chemical — it describes what the compound does, not what it is. Two distinct molecular classes do this through different receptors. GHRH analogs (sermorelin, CJC-1295, tesamorelin) mimic the hypothalamic signal that tells the pituitary to produce GH. Ghrelin receptor agonists (ipamorelin, GHRP-6) work through the growth hormone secretagogue receptor-1a — the same receptor that ghrelin, the hunger hormone, activates naturally. The shared ceiling: both classes depend on a pituitary that can still respond. They don't add GH from outside; they stimulate your pituitary to produce more of its own. Older individuals with reduced pituitary responsiveness see a smaller effect. What separates the classes in practice is the hormonal side-effect profile. GHRH analogs preserve the natural pulsatile pattern of GH release. Some ghrelin receptor agonists — particularly GHRP-6 — also raise cortisol and prolactin, which limits their clinical use. Ipamorelin was developed specifically because it avoids that cortisol spike. Growth hormone secretagogues are distinct from synthetic growth hormone (somatropin) itself. Secretagogues stimulate endogenous production. Somatropin replaces it. That distinction affects pharmacokinetics, regulatory status, and the risk profile.