Growth hormone releasing peptide 2 (GHRP-2), also known as pralmorelin, is a peptide made up of 6 amino acids. GHRP-2 belongs to a family of growth hormone stimulators discovered in the 1980s, which have been extensively studied for their effect on growth hormone release . Despite the different chemical structure of natural ghrelin and GHRP-2, research has shown that GHRP-2 and ghrelin have the same biological actions. GHRP-2 binds to the growth hormone secretagogue receptor (GHSR), which regulates growth hormone release . GHRP-2 works by stimulating the pituitary gland in the brain to produce natural human growth hormone. It enhances growth hormone production by increasing the signal that causes the release of natural growth hormone and it inhibits the activities of somatostatin, which results in further increases in endogenous growth hormone levels. GHRP-2 is the most powerful member of the family of GHRP’s, which makes GHRP-2 a great oral peptide for lean muscle growth and muscle building. A single subcutaneous dose of 1 mg/kg induces a growth hormone peak response of approximately 50 mg/l in normal young men . GHRP-2 or GHRP-6 can be stacked with sermorelin or sermorelin acetate in order to enhance the benefits from each peptide in increasing lean muscle mass and fat loss via the effects of human growth hormone release . Although GHRP-2 and GHRP-6 are both small peptides that stimulate growth hormone release, they each have different chemical and metabolic properties. GHRP-2 causes higher growth hormone release and a lower hunger response in comparison to GHRP-6. Additionally, GHRP-2 results in higher prolactin and adrenocorticotropic hormone secretion when compared to GHRP-6. However, the half-life of GHRP-2 is much shorter than that of GHRP-6 (15 minutes compared to 2 hours), which means that it is eliminated from the body much more rapidly and will require more frequent dosing [7, 8]. GHRP-2 has a shown a number of benefits in human clinical trials, including increases in growth velocity in children, increases in appetite and weight gain in anorexia and normalization of IGF-1 in critically ill patients .
GHRP-2 is stable and effective when administered both orally and intravenously and was demonstrated to be safe in clinical trials using healthy human volunteers . GHRP-2 is packaged into vials as a powder and needs to be completely dissolved in BAC water. GHRP-2 5 mg can be dissolved by adding 2.5 ml of water to provide a 2 mg of GHRP-2 in every 1 ml of solution. These solutions should be stored at 2-8°C for up to one month. For fat loss and muscle gain, three doses of 100 mcg can be administered daily either subcutaneously or intramuscularly. Each dose should be spread throughout the day.
Human clinical trials using GHRP-2 noted mild side effects, including transient increases in appetite and cortisol levels . Headaches have been reported in some patients, but the body will eventually adapt to GHRP-2 and side effects should subside.
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- Kim, K.R., et al., Low-dose growth hormone treatment with diet restriction accelerates body fat loss, exerts anabolic effect and improves growth hormone secretory dysfunction in obese adults. Horm Res, 1999. 51(2): p. 78-84.
- Sigalos, J.T. and A.W. Pastuszak, The Safety and Efficacy of Growth Hormone Secretagogues. Sex Med Rev, 2018. 6(1): p. 45-53.