GHRP-2

GHRP-2 (Growth Hormone-Releasing Peptide-2, CAS 158861-67-7, alternative name pralmorelin or KP-102) is a synthetic hexapeptide with sequence D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2 (817.0 Da), belonging to the ghrelin mimetics family. It was designed by Bowers in the 1980s as an improvement over GHRP-6, with 2-3x higher GH-releasing potency at equimolar dose.

Mechanism of action. GHRP-2 is an agonist of the GHS-R1a receptor (class A GPCR, Gαq coupling → PLC → IP3/DAG → Ca²⁺). Unlike ipamorelin, GHRP-2 moderately elevates ACTH, cortisol and prolactin at pharmacological doses, limiting certain research uses. It also stimulates appetite via the hypothalamic ghrelin/NPY/AgRP axis, an effect exploited in cachexia studies. Plasma half-life is approximately 15-20 minutes.

GHRH synergy. Like all GHRPs, GHRP-2 produces supra-additive synergy with GHRH analogues (CJC-1295, sermorelin, tesamorelin): GH peak 5-10x higher than sum of both peptides alone, via intracellular cAMP (GHRH-R) + Ca²⁺ (GHS-R1a) convergence and somatostatinergic disinhibition.

Clinical and research status. Pralmorelin obtained marketing authorisation in Japan (2006, GHRP Kaken) as a severe somatotropic deficiency diagnostic test. In research, it is studied in osteoporosis, cancer cachexia, anorexia, postoperative ileus and muscle ageing models. Banned by WADA (section S2.2) for sports competition. Lab Peptides France distributes RUO GHRP-2 in 10mg vials, with an HPLC ≥ 98% specification.