Cobalt PeptidesResearch Grade

Scientific Reference

GHRP-2

Evidence profile: Controlled human evidence

GHRP-2, also known by the non-proprietary name pralmorelin, is a synthetic hexapeptide that activates the ghrelin receptor, GHS-R1a. Three of its six residues are D-amino acids, including the non-natural D-2-naphthylalanine, a design feature shared with other synthetic growth hormone-releasing peptides. These compounds were developed by screening for growth hormone release before their receptor had been identified; ghrelin, the receptor's natural ligand, was discovered afterwards. GHRP-2 has been examined in receptor and pituitary cell assays, in animal studies, and in short human endocrine studies that measured hormone secretion. Longer-term human data are sparse, and it is not selective for growth hormone, since rises in other pituitary and adrenal hormones have also been recorded.

Mechanism of Action

GHRP-2 has been reported to act as an agonist at GHS-R1a, a G protein-coupled receptor present on somatotroph cells of the anterior pituitary and on neurons in the hypothalamus. In somatotrophs the receptor couples mainly to Gq and phospholipase C, and the rise in intracellular calcium that follows triggers growth hormone secretion. This route is separate from that of growth hormone-releasing hormone (GHRH), which acts through its own receptor and cyclic AMP. Part of the response is thought to be hypothalamic, through effects on GHRH neurons and on somatostatin signalling. In human studies, modest increases in ACTH, cortisol and prolactin have been reported alongside growth hormone.

Molecular Information

  • Type: Growth hormone secretagogue (GHRP)
  • Length: 6 amino acids
  • Molecular weight: 818.0 g/mol
  • Molecular formula: C45H55N9O6
  • CAS: 158861-67-7

Published Research

  • The combined administration of GH-releasing peptide-2 (GHRP-2), TRH and GnRH to men with prolonged critical illness evokes superior endocrine and metabolic effects compared to treatment with GHRP-2 alone

    Van den Berghe G et al. · Clinical endocrinology · 2002 · Clinical

    PMID 12030918 — View on PubMed

  • Synergy of L-arginine and GHRP-2 stimulation of growth hormone in men and women: modulation by exercise

    Wideman L et al. · American journal of physiology. Regulatory, integrative and comparative physiology · 2000 · Clinical

    PMID 11004017 — View on PubMed

  • Growth hormone-releasing peptide-2 infusion synchronizes growth hormone, thyrotrophin and prolactin release in prolonged critical illness

    Van den Berghe G et al. · European journal of endocrinology · 1999 · Clinical

    PMID 10037246 — View on PubMed

  • Treatment effects of intranasal growth hormone releasing peptide-2 in children with short stature

    Pihoker C et al. · The Journal of endocrinology · 1997 · Clinical

    PMID 9390009 — View on PubMed