Selective GHRP
5mg / vial
Ipamorelin is a pentapeptide and selective growth hormone releasing peptide (GHRP). It is widely regarded in research as the most selective GHRP available — stimulating growth hormone release with minimal observed effects on cortisol, prolactin, or appetite hormones that are commonly elevated by older GHRPs.
Ipamorelin (Aib-His-D-2-Nal-D-Phe-Lys-NH2) is a synthetic pentapeptide GHRP developed in the late 1990s as a more selective alternative to GHRP-6 and GHRP-2. At just 711.9 g/mol, it is the smallest peptide in the Zenic Labs catalogue by molecular weight. Its compact size and selective receptor profile make it one of the most studied GHRPs in published research. Unlike GHRP-6 (which strongly elevates cortisol and appetite) and GHRP-2 (which elevates prolactin), Ipamorelin has been shown in research to produce selective GH release without significant stimulation of ACTH, cortisol, or prolactin at standard research concentrations.
Ipamorelin mimics ghrelin and binds selectively to the GHS-R1a receptor (growth hormone secretagogue receptor type 1a) on pituitary somatotrophs, stimulating GH release. Its selectivity arises from its inability to significantly activate non-GH pituitary hormone release at equivalent concentrations — a property attributed to its specific structural conformation. When combined with CJC-1295 No DAC, the two peptides act synergistically: CJC-1295 No DAC activates the GHRH receptor, increasing the number of somatotrophs firing, while Ipamorelin activates GHS-R1a, increasing GH output per cell. Additionally, both peptides independently suppress somatostatin (the primary inhibitor of GH release), further amplifying the resulting pulse.
Studies have examined Ipamorelin in contexts including GH deficiency models, bone mineral density research, body composition studies, frailty and sarcopenia models, and age-related GH decline. Its clean receptor profile makes it the most frequently referenced GHRP in contemporary research literature. A key comparative study published in Growth Hormone & IGF Research demonstrated Ipamorelin's superior selectivity over GHRP-6 and GHRP-2, establishing it as the benchmark for selective GH secretagogue research. Research has also investigated its potential utility in post-operative recovery models and gastrointestinal motility studies.
Commonly researched with