GHRP-2

Overview

GHRP-2 (pralmorelin) is a synthetic hexapeptide growth hormone secretagogue that acts through the same ghrelin receptor (GHS-R1a) pathway as GHRP-6 and hexarelin. Unlike more recently developed, more selective secretagogues such as ipamorelin, GHRP-2 also stimulates ACTH/cortisol release and appetite as documented side effects of its GH-releasing activity.

Proposed Mechanism of Action

GHRP-2 activates GHS-R1a at both pituitary and hypothalamic sites, stimulating GH release through calcium-channel and protein kinase C-linked signaling — the same receptor ghrelin (the body's endogenous "hunger hormone") acts on, which is the likely basis for GHRP-2's reported appetite-stimulating side effect.

Research Context

The cited study is a genuine pediatric human clinical trial: children with short stature received intranasal GHRP-2 and showed both an acute GH response and, over 6-24 months, meaningfully increased height velocity compared to their own pre-treatment baseline. This is more direct human outcome data than exists for several other GH secretagogues covered on this site.

Limitations of the Current Evidence

• The cited trial is in children with diagnosed short stature — a specific clinical population, and results (height velocity increases) reflect a growth-plate-open pediatric context that doesn't extend to adult use claims.
• GHRP-2's non-selective hormonal profile (raising ACTH/cortisol alongside GH) is a meaningful practical difference from newer secretagogues like ipamorelin — the two are not interchangeable despite both being called "GH secretagogues."