Ipamorelin
$Selective GH secretagogue; Still not a benign wellness shortcut
Ipamorelin is a ghrelin-receptor agonist used to stimulate GH release with less cortisol and prolactin spillover than older GHRPs.
It is cleaner than GHRP-2/GHRP-6 pharmacologically, but not FDA-approved for broad wellness use. Body-composition and recovery claims still need evidence. Focus on the GH pulse concept. Track IGF-1, glucose, edema, sleep apnea symptoms, and desensitization rather than assuming more is better.
Classification details
- A synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) and selective agonist of the ghrelin receptor (GHS-R1a).
- Developed in the late 1990s by Novo Nordisk as a third-generation growth-hormone-releasing peptide (GHRP).
- Known as the “cleanest” GHRP: it has the highest selectivity for growth-hormone release, without the cross-reactivity seen in earlier GHRPs.
- Ipamorelin is a selective ghrelin/GHS-R agonist GH secretagogue. It is distinct from GHRP-2/GHRP-6/hexarelin because its appeal is lower cortisol/prolactin spillover, not simply stronger GH release.
- Selective GH release: triggers a GH pulse at the ghrelin receptor but, unlike GHRP-2 or GHRP-6, does not meaningfully raise ACTH, cortisol, or prolactin even at higher doses.
- Preserved pulsatility: it enhances the body's natural pulsatile GH pattern rather than forcing a constant, unphysiological release.
- Somatostatin inhibition: suppresses the body's main GH off-switch, letting the natural GHRH signal work more effectively.
- Secondary IGF-1 rise: downstream liver IGF-1 increases and drives systemic repair. IGF-1 is the usual marker but not a complete safety or efficacy endpoint.
- It stimulates GH pulses through GHS-R while generally being described as more selective in endocrine spillover. Pituitary reserve, sleep, nutrition, and age influence response.