Ipamorelin — 10mg

Ipamorelin is a synthetic pentapeptide ghrelin receptor (GHSR-1a) agonist developed by Novo Nordisk in the late 1990s as a refined growth hormone secretagogue. Its defining property is selectivity: unlike earlier GHRPs (GHRP-2, GHRP-6, hexarelin), which produce significant elevations in cortisol, prolactin, and occasionally aldosterone alongside growth hormone (GH), Ipamorelin produces essentially clean GH release with no clinically meaningful effect on other pituitary axes. This selectivity made it a pharmacological probe for dissecting the ghrelin receptor's GH-releasing function from its broader endocrine effects, and has positioned it as the preferred GHS in research contexts where hormonal interference would confound interpretation.

At the receptor level, Ipamorelin binds GHSR-1a on pituitary somatotropes with high affinity, triggering Gq-coupled signaling that depolarizes the cell and drives GH secretion. The peptide also suppresses somatostatin tone — the physiological brake on GH release — which amplifies the GH pulse. Its pentapeptide structure (Aib-His-D-2-Nal-D-Phe-Lys-NH₂) is compact enough for reliable subcutaneous bioavailability with a half-life of approximately two hours, supporting flexible dosing protocols typically administered before sleep (to align with endogenous slow-wave-sleep GH pulses) or post-exercise.

Research applications span body composition and recovery contexts, age-related GH decline (somatopause), sleep architecture, and fracture healing where local GH/IGF-1 signaling accelerates callus formation. Ipamorelin is frequently studied as a monotherapy in protocols where clean GH signaling is needed for mechanistic analysis, or in combination with a GHRH-class peptide (CJC-1295, sermorelin, tesamorelin) where the two mechanisms synergize to produce pulsatile GH release mimicking endogenous patterns. Its clean pharmacological profile has also made it a reference compound against which newer ghrelin receptor agonists are benchmarked.