What is GHRP-2?
GHRP-2 is a synthetic agonist of ghrelin, the newly-discovered gut peptide which binds to the growth hormone (GH) secretagogue receptor. Ghrelin has been shown to have two major effects, stimulating both GH secretion and appetite/meal initiation. GHRP-2 has been extensively studied for its utility as a growth hormone secretagogue (GHS). Animal studies have shown its effect on food intake. However, whether GHRP-2 can also stimulate appetite in humans when administered acutely is not known. We subcutaneously infused 7 lean, healthy males with GHRP-2 (1μg/kg/h) or saline for 270 minutes and then measured their intake of an ad libitum, buffet-style meal. Similar to what has been reported for ghrelin administration, our subjects ate 35.9±10.9 % more when infused with GHRP-2 vs. saline, with every subject increasing their intake even when calculated per kg body weight (136.0±13.0 kJ/kg vs 101.3±10.5 kJ/kg, p=0.008). The macronutrient composition of consumed food was not different between conditions. As expected, serum GH levels rose significantly during GHRP-2 infusion (AUC 5550±1090 μg/L/240 min vs. 412±161 μg/L/240 min, p=0.003). These data are the first to demonstrate that GHRP-2, like ghrelin, increases food intake, suggesting that GHRP-2 is a valuable tool for investigating ghrelin effects on eating behavior in humans.
GHRP-2 Functions and Actions:
This peptide essentially could make the body to produce more human growth hormone. It works to stimulate centralized GH production along with a substance called ghrelin. Ghrelin is a neurological hormone that basically tells your body when you’re hungry, and it also has some regulatory functions in food intake and absorption, in addition to secretion of digestive acids. Also, GHRP-2 works to suppress somatostatin, which is a hormone that inhibits the release of GH in the body.
Because high ghrelin levels lead to extreme hunger, and we do not advise some peptides due to this side effect. In fact, the sister hormone of GHRP-2, GHRP-6 is a culprit when it comes to causing higher levels of hunger. GHRP-2 is a better choice since it stimulates very similar effects sans the extreme ghrelin increase that leads to hunger. But this isn’t to say that there won’t be a little bit of increased hunger. You’ll definitely feel hunger on this peptide than without it, but the effects it has on the body are outstanding. It’s just a flatout good thing to have more GH going throughout your entire system.
Blandine Laferrère, Obesity Research Center, St Luke’s Roosevelt Hospital Center, 1090 Amsterdam Avenue, New York, NY 10025.
Cynthia Abraham, Obesity Research Center, St Luke’s Roosevelt Hospital Center, 1090 Amsterdam Avenue, New York, NY 10025.
Colleen D. Russell, Obesity Research Center, St Luke’s Roosevelt Hospital Center, 1090 Amsterdam Avenue, New York, NY 10025.
Cyril Y. Bowers, Tulane University Health Sciences Center, New Orleans, Louisiana 70112.