Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin.

Metabolites of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin were identified in urine after nasal administration, with detection windows ranging from 12 to 47 hours depending on the peptide and metabolite. Parent compounds were often undetectable while metabolites remained present for longer periods.

Each peptide was administered nasally to a single volunteer. Urine samples were collected for 48 hours post-administration, processed via solid-phase extraction, and analyzed using nano-liquid chromatography coupled with high-resolution mass spectrometry to identify parent compounds and metabolites.

Understanding the metabolism and excretion timelines of GHRPs is crucial for developing reliable anti-doping tests and ensuring fair competition in sports. It also informs how these peptides behave in the body after nasal administration.

The study involved only one volunteer per peptide, limiting generalizability. The exact study type and evidence strength were not specified, and nasal administration may differ from other routes.