Ipamorelin is a pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH₂) that acts as a selective agonist of the ghrelin/growth hormone secretagogue receptor (GHS-R). Unlike GHRP-2 and GHRP-6, ipamorelin does not significantly stimulate cortisol, prolactin, or ACTH, making it the cleanest GHRP available for isolated GH pulse research.
CAS 170851-70-4 | MW 711.9 DaBinds selectively to the ghrelin receptor (GHS-R1a) in the pituitary and hypothalamus, triggering pulsatile GH release.
Studies show ipamorelin does not raise cortisol, prolactin, or ACTH at research doses — unique among GHRPs.
Combined with GHRH analogues like CJC-1295, ipamorelin produces amplified GH pulses via dual receptor stimulation.
Mimics physiological GH secretion pattern, preserving negative feedback loops and avoiding receptor downregulation.
Raun et al. (1998) demonstrated that ipamorelin stimulated GH release at equivalent potency to GHRP-6 in rats, but without the ACTH or cortisol response seen with GHRP-2 and GHRP-6, establishing ipamorelin as the first truly selective GHRP.
Eur J Endocrinol. 1998;139(5):552–561Svensson et al. found ipamorelin increased bone mineral density in ovariectomized rats after 12 weeks of treatment, suggesting potential applications in bone metabolism research.
Growth Horm IGF Res. 2000;10(5):266–272Multiple rodent studies confirm ipamorelin reliably elevates both GH and downstream IGF-1 levels in a dose-dependent manner, supporting its use as a tool compound for GH axis research.
J Endocrinol. 1999;163(3):487–495In rodent studies, ipamorelin has been administered at 200–300 µg/kg subcutaneously. In primates and clinical pilot work, doses between 30–300 µg per injection have been investigated. Protocols typically examine 1–3 injection timing windows per day to correlate with natural GH pulse patterns.
| Full Name | Ipamorelin |
| CAS Number | 170851-70-4 |
| Molecular Formula | C₃₈H₄₉N₉O₅ |
| Molecular Weight | 711.9 Da |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH₂ |
| Purity | ≥99% by HPLC |
| Appearance | White lyophilized powder |
| Storage | −20°C, desiccated |
| Format | Lyophilized vials |
