New Mass Spectrometry Test for the Hunger Hormone Ghrelin Finds None in Urine — A Challenge for Doping Detection

Two LC-MS/MS strategies were developed: a bottom-up approach (peptide digestion) for plasma and a top-down approach (intact peptide analysis) for urine. Both used solid-phase extraction for sample enrichment and cleanup. Methods were validated for limits of detection, recovery, precision, and accuracy. Plasma from healthy volunteers was analyzed as proof of concept.

Ghrelin is a WADA-banned substance, but detecting its misuse requires reliable analytical methods. This study reveals that urine-based ghrelin testing — the standard approach for most doping controls — may be fundamentally flawed because ghrelin doesn't appear to be present in urine at detectable levels. This has significant implications for how anti-doping labs approach peptide hormone testing.

As peptide hormones become increasingly common as both therapeutic agents and potential doping substances, anti-doping laboratories need to evolve from traditional immunoassay methods to more specific mass spectrometry approaches. This study exemplifies how improved analytical specificity can overturn previous findings and force a reassessment of testing strategies — a pattern likely to repeat as more peptide hormones come under anti-doping scrutiny.

Only a small number of healthy volunteers were tested — no samples from individuals who actually used exogenous ghrelin were available. The absence of ghrelin in urine contradicts earlier immunoassay-based findings but needs independent confirmation. The study did not assess whether exogenously administered ghrelin might appear in urine at higher concentrations than endogenous levels.