GHRP-2 (a.k.a. Pralmorelin) is a synthetic growth hormone secretagogue known to bind to the ghrelin/growth hormone secretagogue receptor. It was the first of the growth hormone secretagogues to be introduced and is currently marketed as a test peptide for the assessment of growth hormone deficiency and secondary adrenal failure. GHRP-2 has been investigated in stage II clinical trials for the assessment of short stature and is under active research for its effects on appetite, muscle growth, the immune system, and sleep cycles. GHRP-2 is orally and sublingually active, so it does not have to be injected to have its effects. Research in Yaks indicates that GHRP-2 can boost muscle growth in two ways: increased protein deposition and decreased protein degradation. The research showed that GHRP-2 can overcome natural growth plateaus that occur in yaks due to food deprivation, disease, and adverse environmental conditions (e.g. cold). The most profound finding from this study is that GHRP-2 reduces muscle atrophy by inactivating atrogin-1 and MuRF1, proteins that control the muscle degradation pathway. Of course, by activating growth hormone and insulin-like growth factor-1, GHRP-2 helps to boost muscle protein deposition. The combined effect of reducing degradation and enhancing deposition is that GHRP-2 encourages the development of lean body mass even in adverse conditions.