GHRP-2
GHRP-2 (pralmorelin) is a synthetic hexapeptide growth hormone secretagogue that activates the ghrelin receptor to stimulate growth hormone release and is used clinically in some countries as a diagnostic agent for growth hormone deficiency, but it also increases appetite and modestly raises cortisol and prolactin.
This page is a research-orientation summary, not a dosing guide. For anything beyond general background, read the primary literature or talk to a qualified clinician — specifics like amount, frequency, or administration aren't something we publish here.
What it does & how it works
GHRP-2 is a synthetic agonist of the growth hormone secretagogue receptor (GHS-R1a), the same receptor activated by endogenous ghrelin, expressed on pituitary somatotrophs and in the hypothalamus. Receptor activation triggers phospholipase C/inositol trisphosphate signaling and calcium mobilization in somatotrophs, stimulating GH release both directly at the pituitary and indirectly by modulating hypothalamic GHRH and somatostatin tone. Because it engages the same receptor as ghrelin, it also produces ghrelin-like effects outside the GH axis, including stimulation of appetite and, to a lesser extent, ACTH/cortisol and prolactin release.
Typical results seen in research
Human studies show GHRP-2 produces robust, dose-dependent GH release, and it is used as a standardized diagnostic stimulation test to distinguish adult growth hormone deficiency from normal pituitary function, with defined GH cutoff values established in clinical validation studies. Separately, controlled human studies found that GHRP-2 significantly increases food intake in healthy men, consistent with its ghrelin-receptor agonism, and it modestly raises cortisol and prolactin compared with more selective secretagogues like ipamorelin.
How it’s commonly used
In diagnostic and research contexts, GHRP-2 is administered as an intravenous bolus (for standardized GH stimulation testing) or by subcutaneous injection in other research settings. It is approved as a diagnostic reagent in some countries but is not approved as a general therapeutic agent.
- Drugs in R&D · 2004 Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102LN
- European Journal of Endocrinology · 2007 A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency
- Journal of Endocrinological Investigation · 2005 Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men
Curated from published literature for research orientation. Not an exhaustive review, and not a substitute for reading primary sources.