Evaluation of endogenous steroid sulfates and glucuronides in urine after oral and transdermal administration of testosterone. Part II: Female participants

Detecting testosterone (T) doping remains a significant challenge, driving the search for novel biomarkers and advancements in the steroidal Athlete's Biological Passport (ABP). Phase II metabolites of endogenous anabolic androgenic steroids (EAAS) have emerged as promising biomarkers, demonstrating prolonged detection times (DTs) and greater sensitivity compared to conventional biomarkers. Studies involving male participants investigated the effect of intramuscular, oral, and transdermal administration of T on these biomarkers and proposed their integration in future urinary steroid profiling. However, before the inclusion of phase II EAAS metabolites, it is crucial to address a range of possible doping scenarios and the influence of known confounding factors, like ethnicity or sex, on the steroid profile. This study addresses this gap by investigating the impact of oral and transdermal T administration on phase II EAAS metabolites in both men and women. This second part of the study presents the results for female participants, which have not been included in prior research on this topic. Results partially confirm the trends observed in men, with sulfate ratios exhibiting prolonged detection times and higher sensitivity compared to conventional steroid profile biomarkers following multiple oral and transdermal T administration. However, the evaluation in women showed greater variability due to lower steroid concentrations and greater fluctuations influenced by the menstrual cycle. This study provides additional evidence supporting the inclusion of phase II EAAS metabolites for enhanced detection of T doping. Further, it underscores the need for further research to address the unique challenges of female steroid profiling.