New GHRP-2 Analogue Discovered in Seized Vial, Posing Doping Challenge

Growth hormone releasing peptides (GHRPs) are synthetic compounds known to stimulate human growth hormone (hGH) secretion, often misused by athletes for performance enhancement. While several GHRPs exist, only GHRP-2 (Pralmorelin) has clinical approval, yet many circulate on the black market. The World Anti-Doping Agency (WADA) prohibits GHRPs, but analytical methods primarily rely on detecting known structures, leaving a knowledge gap regarding novel, modified GHRPs designed to evade detection.

The analysis successfully identified a novel heptapeptide with a molecular weight of 874.02 Da within the seized vial. Through detailed de novo sequencing, the peptide's structure was determined to be a glycine analogue of GHRP-2, meaning it shares a similar backbone but with a subtle modification involving a glycine residue. This structural alteration is significant because it represents a slight chemical deviation from the known GHRP-2. The study unequivocally identified a new heptapeptide that is a glycine analogue of GHRP-2, demonstrating a potential strategy for circumventing existing anti-doping detection methods. This finding indicates that illicit manufacturers are creating modified versions of prohibited substances, making their detection more challenging for standard screening protocols.