Detection of testosterone esters in blood

Abstract

Injections of synthetic esters of testosterone are among the most common forms of testosterone application. In doping control, the detection of an intact ester of testosterone in blood gives unequivocal proof of the administration of exogenous testosterone. The aim of the current project was to investigate the detection window for injected testosterone esters as a mixed substance preparation and as a single substance preparation in serum and plasma. Furthermore, the suitability of different types of blood collection devices was evaluated. Collection tubes with stabilizing additives, as well as non-stabilized serum separation tubes, were tested. A clinical study with six participants was carried out, comprising a single intramuscular injection of either 1000 mg testosterone undecanoate (Nebido(®)) or a mixture of 30 mg testosterone propionate, 60 mg testosterone phenylpropionate, 60 mg testosterone isocaproate, and 100 mg testosterone decanoate (Sustanon(®)). Blood was collected throughout a testing period of 60 days. The applied analytical method for blood analysis included liquid-liquid extraction and preparation of oxime derivatives, prior to TLX-sample clean-up and liquid chromatography-tandem mass spectrometry (LC-MS/MS) detection. All investigated testosterone esters could be detected in post-administration blood samples. The detection time depended on the type of ester administered. Furthermore, results from the study show that measured blood concentrations of especially short-chained testosterone esters are influenced by the type of blood collection device applied. The testosterone ester detection window, however, was comparable.

Detection of testosterone doping in female athletes

“…Serum T measurement was performed in two World Anti-Doping Agency (WADA)-accredited laboratories using LC−MS. [12][13][14] Urine steroid profiles were analyzed in WADA-accredited laboratories according to the international standards for measurement of endogenous androgens. 2 The urine T/E ratio was never elevated in either athlete including times before, during, and after the suspicious blood samples.…”

“…In these female athletes the available evidence does not allow determining which testosterone product(s) were used although measuring serum T would identify the use of any T esters or non-esterified T. The injection of exogenous T could have been identified by the presence of circulating testosterone ester. 14…”

Annual banned‐substance review: analytical approaches in human sports drug testing

“…Another advantage of serum and/or plasma sampling concerning test methods supporting the detection of testosterone misuse is the option of targeting intact testosterone esters, which represents a frequently employed formulation of the AAS. Over a period of up to 60 days, the single intramuscular administration of therapeutic testosterone ester preparations is traceable as demonstrated in a study by Forsdahl et al . Using an established LC‐ESI‐MS/MS analytical approach, the constituents of a mixed formulation consisting of four T esters (T propionate, T phenylpropionate, T isocaproate, and T decanoate) were determined up to 20 days, while T undecanoate as commonly used in monotherapy was monitored up to day 60 post injection.…”

An Intramuscular Injection of Mixed Testosterone Esters Does Not Acutely Enhance Strength and Power in Recreationally Active Young Men

“…If conducting such studies, measurable effects are most likely to occur at the time point where maximal pharmacological activity is expected. Based on plasma analysis following Sustanon ® 250 administration, peak circulatory concentrations of the esters occur within 24-72 h of post-injection, with individual differences and depending on the length of the ester side chain (Forsdahl et al, 2015). Therefore, given the timeline of reported biological effects and pharmacokinetics, we tested the hypothesis that an intramuscular injection of 250 mg mixed testosterone esters (TEs; Sustanon ® ) enhances physical performance in countermovement jump (CMJ), 30-s all out cycle sprint, and one-arm isometric elbow flexion acutely 24 h after injection.…”