Intranasal Delivery of Testosterone and Its Effect on Doping Markers

Testosterone is a substance commonly abused in the sporting world despite being banned by all American sports leagues, international federations, and the World Anti-Doping Agency. Current methods employed to detect exogenously administered testosterone include direct detection using isotope ratio mass spectrometry (IRMS) and indirect detection using the athlete biological passport (ABP). However, different formulations of testosterone (oral, transdermal, sublingual, etc) are expected to result in characteristic IRMS profiles, affect the ABP readings in unique ways, and differ in their windows of detection. In 2014, a new formulation of testosterone, Natesto, which is administered intranasally, was FDA approved. Though only approved for medical use, it is expected athletes may use this product, and its effect on steroid doping markers has yet to be determined. Characterization of this detection profile is necessary for confirmation of the exact product being administered in an anti-doping setting. In this study, the investigators aim to understand the effects on the steroid doping profile following a single administration of Natesto to healthy, active volunteers. Windows of detection will be determined for the standard dosing of Natesto, and the effects on ABP markers and IRMS profiles will also be established.