Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men

This was the first study to demonstrate that GHRP-2 increases food intake in humans, establishing a direct functional link between this synthetic GH secretagogue and the orexigenic ghrelin system. The crossover, double-blind, placebo-controlled study evaluated healthy men who received intravenous GHRP-2 (1 µg/kg) or saline before an ad libitum buffet.

The results were impressive: participants who received GHRP-2 consumed 35.9% more calories compared to the saline group, with a significant increase in total caloric intake. This orexigenic effect was accompanied by significant elevation of serum GH levels, confirming the dual action of the peptide on GH secretion and appetite regulation.

GHRP-2 acts as an agonist of the GH secretagogue receptor (GHS-R1a), which is the same endogenous receptor for ghrelin — the "hunger hormone." The demonstration that GHRP-2 mimics the orexigenic effect of ghrelin was particularly relevant for understanding the appetite-increasing side effects observed with clinical use of GH secretagogues.

The authors emphasized that this property has bidirectional therapeutic implications: it may be beneficial for patients with cachexia or anorexia associated with chronic diseases, but represents an important consideration for individuals using GHRP-2 for other effects, such as GH increase, who wish to control body weight.