GHRP-6

GHRP-6 (Growth Hormone-Releasing Peptide-6, CAS 87616-84-0) is a synthetic hexapeptide with sequence His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (872.0 Da), the first GHRP identified by Cyril Bowers in 1984 from systematic study of modified enkephalins. It served as pivotal molecule to identify the GHS-R1a receptor in 1996, even before the discovery of ghrelin (endogenous ligand) by Kojima in 1999.

Pharmacological characteristics. GHS-R1a agonist with EC50 ~5-10 nM on the rat pituitary line, GHRP-6 exhibits lower potency than GHRP-2 and ipamorelin for GH release but much more marked appetite stimulation via the hypothalamic ghrelin/NPY/AgRP axis. This property makes it a preferred tool for studies on cachexia, anorexia, eating disorders and appetite regulation.

Ancillary effects. Like GHRP-2 but more pronounced, GHRP-6 moderately elevates prolactin, ACTH and cortisol at repeated doses. It has also been described to modulate the cardiovascular axis via the CD36 receptor (scavenger receptor B type 2), identified as alternative GHRP cardiotropic target (Bodart 2002 Circ Res), with cardioprotective effects in rodent ischaemia-reperfusion models. Plasma half-life is 20-30 minutes.

Research uses. GHRP-6 is studied preclinically in myocardial infarction models, heart failure, cancer cachexia (C26, MCA-38), muscular dystrophy, growth retardation and obesity (paradoxical effects via reduced energy expenditure). Banned by WADA. Lab Peptides France markets RUO GHRP-6 in 10mg vials, with an HPLC ≥ 98% specification.