Background To investigate the erythropoietic activity and safety aspects of testosterone undecanoate (TU) injections in transgender men, assigned female at birth.Methods Twenty-three men (13 hypogonadal cisgender men and 10 transgender men) who initiated TU at the study start (naive) and 15 men (10 hypogonadal cisgender men and 5 transgender men) on steady-state treatment with TU (non-naive) were included in this prospective 1-year observational study. A control group of 32 eugonadal cisgender men was investigated once at baseline. Complete blood count, testosterone in serum and saliva, and plasma lipids, and liver enzymes were assessed.Results For naive transgender men, a significant increase in hemoglobin concentration was noted (mean (SD)), 141 (8) g/L to 151 (13) g/L, while no increase was seen in naive hypogonadal cisgender men. At the end of the study, naive transgender men exhibited comparable levels of hemoglobin, hematocrit, and testosterone levels in serum and saliva to hypogonadal cisgender men, as well as to the eugonadal cisgender men. During the study, HDL-cholesterol decreased significantly in naive transgender men, 1.4 (0.4) mmol/L to 1.2 (0.4) mmol/L, P = 0.03, whereas no significant change was noted in naive hypogonadal cisgender men. Liver enzymes remained unchanged in all groups.Conclusions After 12 months of treatment with TU in naive transgender men, hemoglobin and hematocrit increased to levels within the cisgender male reference range. A slight decrease in HDL-cholesterol was seen in naive transgender men but liver enzymes remained unchanged.

A highly sensitive and accurate electrospray liquid chromatography tandem-mass spectrometry (ESI-LC–MS/MS) method for determination of testosterone in human serum and saliva was developed and validated. Accurate quantification of testosterone in human matrices is essential in diagnosis and management of androgen status in men, women and children, and in forensic investigations of suspected abuse of anabolic androgenic steroids. Chromatography was performed on an HSS-T3 C18 column with a total run-time of 5.5 min. The tandem mass spectrometry was operated in positive electrospray ionization mode with multiple reaction monitoring. Serum and saliva samples of 200 μL, were prepared by solid-phase extraction using a 96-well plate following precipitation with 200 μL methanol. 13C labeled testosterone was used as internal standard for quantification. The standard curve was linear within the range of 4−1000 pg/mL and the limit of quantification of both serum and salivary testosterone was 4 pg/mL. Accuracy were 99–101 % and 93–95 % with between-run imprecision in serum and saliva, respectively, and inter- and intra-assay coefficients of variation were less than 9.2 %. The method proved to be applicable for determination of testosterone over a wide range of concentrations in serum and saliva samples from clinical patients with various androgen disorders, healthy male and female adults as well as from forensic cases.

At the Swedish national forensic toxicology laboratory, a measured testosterone/epitestosterone (T/E) ratio?≥?12 together with testosterone/luteinizing hormone (T/LH) in urine?>?400?nmol/IU is considered as a proof of exogenous testosterone administration. However, according to the rules of the World Anti-Doping Agency (WADA), samples with T/E ratio?>?4 are considered suspicious and shall be further analysed by gas chromatography?combustion?isotope ratio mass spectrometry (GC-C-IRMS) to confirm the origin of testosterone and its metabolites. The aim of this study was to investigate the possibility of false negative results and to estimate the frequency of negative results using the current criteria for detection of abuse of testosterone in forensic investigations. Urine and serum samples were collected by the police at suspected infringement of the doping law in Sweden. Fifty-eight male subjects were included in the study. Urinary testosterone was determined by gas chromatography?mass spectrometry (GC?MS), serum testosterone and LH?by immunoassay. The origin of testosterone and its metabolites was confirmed by means of GC-C-IRMS. Twenty-six of the 57 analysed subjects tested positive for exogenous testosterone using the criteria T/E?≥?12 combined with T/LH?>?400?nmol/IU. The IRMS analyses confirmed 47 positives; thus, 21 were considered false negatives. Negative predictive value was 32% (95% confidence interval [CI]: 16%?50%) and sensitivity 55%. No false positive subjects were found. The number of false negative cases using the current criteria for the detection of testosterone abuse and hence the low sensitivity indicates a need to discuss introduction of new strategies in forensic doping investigations.