Ipamorelin is a highly selective growth hormone-releasing peptide (GHRP) that stimulates the release of growth hormone from the pituitary gland. It is the first GHRP-receptor agonist with selectivity for GH release similar to that displayed by GHRH, distinguishing it from other GHRPs by not affecting ACTH, cortisol, prolactin, FSH, LH, or TSH levels even at doses over 200-fold higher than the ED50 for GH release.
~2 hours
Subcutaneous injection
1
711.85 Da
Ipamorelin mimics the body's natural growth hormone-releasing hormone by binding to the growth hormone secretagogue receptor (GHSR/ghrelin receptor) in the pituitary gland, stimulating the release of endogenous growth hormone. Unlike other GHRPs such as GHRP-6 and GHRP-2, ipamorelin does not stimulate the release of ACTH or cortisol, making it the most selective growth hormone secretagogue available.
Ipamorelin is a pentapeptide growth hormone secretagogue notable for being the first truly selective GHRP-receptor agonist. Unlike other GHRPs (GHRP-6, GHRP-2), it stimulates GH release without affecting cortisol, ACTH, prolactin, or appetite hormones even at supraphysiological doses. Human pharmacokinetic studies demonstrate a 2-hour half-life with predictable GH pulse response. A Phase 2 RCT with 117 patients showed excellent tolerability. Research demonstrates benefits for bone growth, nitrogen balance, and postoperative recovery, though large-scale efficacy trials for muscle growth and fat loss are lacking.
Aib-His-D-2-Nal-D-Phe-Lys-NH2