Advances in the detection of growth hormone releasing hormone synthetic analogs.
This study, motivated by anti-doping enforcement, investigated the in vitro metabolism and urinary detection of four synthetic growth hormone releasing hormone (GHRH) analogs: sermorelin, tesamorelin, CJC-1295, and CJC-1295 with drug affinity complex (DAC). Because these compounds are banned by the World Anti-Doping Agency (WADA) yet rarely detected in accredited laboratory samples—likely due to low urinary concentrations and poorly understood metabolism—researchers used in vitro methods to identify 19 major metabolites. These metabolites were synthesized, purified, and characterized in-house to serve as reference materials. Using these standards alongside commercially available parent compounds and one known sermorelin metabolite (sermorelin(3-29)-NH₂), the team developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method applied to fortified (spiked) urine samples. Limits of detection were generally at or below 1 ng/mL, meeting WADA's required performance threshold. Key limitations include the in vitro nature of the metabolism work, meaning real-world in vivo metabolite profiles in humans may differ, and no actual athlete or clinical urine specimens were analyzed. The study advances analytical capability for anti-doping testing but does not evaluate physiological or clinical effects of these peptides.