GHRP-2

GHRP-2 (growth hormone-releasing peptide 2), also called pralmorelin, is a synthetic peptide developed to mimic the natural hormone ghrelin's effects on the growth hormone (GH) secretagogue receptor. It functions as a potent secretagogue by stimulating the release of growth hormone and increasing appetite.

Originally synthesized in the 1990s through collaborative efforts involving Tulane University and Polygen in Germany, GHRP-2 emerged from a series of small peptides designed to effectively stimulate GH secretion with potential applications in diagnosing GH deficiency and studying metabolic regulation.

In preclinical and clinical research, GHRP-2 is primarily investigated for its ability to increase circulating GH levels and influence feeding behavior. Its role as a ghrelin receptor agonist makes it valuable for exploring the physiological pathways governing growth, metabolism, and appetite regulation.

Despite extensive research interest, GHRP-2 remains a research-use-only compound without regulatory approval for therapeutic use. It is utilized in laboratory studies to better understand GH axis modulation and related metabolic processes.

Research on GHRP-2 has explored its pharmacological profile, physiological effects, and metabolism in humans. The 2004 study titled "Pralmorelin: GHRP 2, GPA 748..." outlined its development as an orally active synthetic peptide capable of significantly elevating plasma GH levels across diverse populations, highlighting its diagnostic potential in GH deficiency.

The 2005 study "Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men" demonstrated that subcutaneous infusion of GHRP-2 increased food intake by approximately 36% in healthy males, alongside a significant rise in serum GH levels, confirming its orexigenic and secretagogue effects in humans.

A 2015 investigation into the metabolism of GHRP-2 after nasal administration characterized its urinary metabolites, detecting the parent compound and metabolites up to 47 hours post-dose. This study contributed to anti-doping research by establishing detection methods for GHRPs and their metabolites, reflecting the compound's relevance in sports pharmacology research.

Research studies investigating GHRP-2 have employed various administration routes including subcutaneous, buccal, oral, and nasal delivery. For example, subcutaneous infusion protocols in human studies have used doses around 1 microgram per kilogram per hour to evaluate acute effects on GH secretion and appetite.

Precise dosing regimens vary across studies and depend on the research objective, with no standardized or clinically approved dosing established. Researchers typically tailor doses to elicit measurable endocrine responses while monitoring safety parameters. Due to the lack of regulatory approval and established clinical guidelines, dosing information remains confined to controlled research environments.