GHRP-2
GH secretagogue (ghrelin receptor agonist)
Also known as: Pralmorelin, KP-102, GPA-748
Evidence is limited to animal or in-vitro work. No human pharmacokinetics. Any human dose in circulation is extrapolated, and extrapolation across species routinely fails.
No published human plasma half-life was located, including in the KP-102 pharmacology papers. Urinary excretion data exist for anti-doping purposes, GHRP-2 and its free-acid metabolite are detectable in urine up to 47 hours after administration, but a urinary detection window is NOT a half-life and must not be read as one. A rat study reports ~50% intranasal bioavailability and no half-life.
The only sourced human dose is DIAGNOSTIC, not therapeutic: 100 mcg intravenously as a single bolus for the GH-releasing peptide-2 test for adult GH deficiency, with GH measured over the following 2 hours. This is a one-time diagnostic challenge, not a repeated-administration therapeutic dose. No published subcutaneous therapeutic range exists.
Approval is narrow and diagnostic, a single-dose challenge test in one country. That is not evidence supporting repeated therapeutic use, which has not been studied.
GHRP-2 is a ghrelin receptor agonist and co-stimulates ACTH/cortisol and prolactin in addition to GH, a key difference from ipamorelin. Animal general-pharmacology work showed no obvious effect on CNS, autonomic, respiratory, cardiovascular, digestive, renal, or haematologic systems at pharmacological doses. Human safety beyond single diagnostic doses is not characterised; repeated therapeutic use has not been studied.
- A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency · pubmed
- Pharmacological characteristics of KP-102 (GHRP-2), a potent growth hormone-releasing peptide · pubmed
- Determination of growth hormone releasing peptides metabolites in human urine after nasal administration · pubmed