One injection…would have been even more interesting to see how these guys did with the game at the end of the week, at trough, comparing results within the subjects. Also, wish they would have put them on a normal TRT protocol and followed them for several weeks. Also, they played a game, it would be cool to somehow measure real life actions and decisions. Not sure what that could be, business decisions, financial, stepping out on committed relationships, etc.?
Appointment 3: Injection.
At the third appointment, participants received a single i.m. injection. Participants in the treatment group were administered a 1-mL dose of testosterone enanthate (250 mg; Androtardyl/Testoviron Depot), whereas participants in the placebo group were administered 1 mL saline; i.m. testosterone enanthate is a long-acting ester of testosterone. The pharmacokinetics of testosterone enanthate yields supraphysiological testosterone levels in serum as early as 2 h after injection, reaching peak levels four to five times above basal between 8 and 24 h after injection (72, 73).
Appointment 4: Testing.
At the fourth appointment, which took place on the following day, blood samples were collected for the measurement of serum testosterone concentrations. These samples were collected 17.5–20 h after the injection of testosterone or placebo. All participants were then given oral and written instructions for both the modified UG task (Fig. 1) (detailed below) and a gambling task not presented here. Participants rated pictures of the proposers’ faces for trustworthiness, dominance, frustration, angriness, friendliness, happiness, and attractiveness and played a short practice session before undergoing MRI. The scanning lasted ∼80 min (15 min of anatomical imaging and 65 min of functional imaging), during which participants completed both the modified UG task and the gambling task. After scanning, participants again rated the proposers for trustworthiness, dominance, frustration, angriness, friendliness, happiness, and attractiveness and completed the SADI, the BDI, the POMS, the IPIP, the Mach IV, the EPQ-R, the BAI, and the certainty equivalents task. Participants also reported whether they believed they had received testosterone and described the effects that they would expect testosterone administration to have on themselves and others. Participants were paid their summed earnings from the UG task, the gambling task, and the outcome of a randomly selected trial from the certainty equivalents task or €80, whichever was greater. The analysis of the neuroimaging data will be presented in a separate paper.
Appointment 5: Medical Follow-Up.
Finally, participants attended the endocrinologist again 4–6 wk after the injection. A physical examination was carried out, and blood samples were collected and analyzed for hematocrit, lipid profile, PSA, liver, renal profile, and hormonal status to assess any potential changes after testosterone administration. Paired sample t tests were used to compare the parameters at baseline and follow-up. There were no significant changes in hemoglobin, hematocrit, total cholesterol and its fractions, and PSA concentrations after either of the injections. Two men enrolled in the study reported pain at the injection sites, which fully resolved after 2 d. One participant in the placebo group reported increased libido after injection. Participants were paid €50 for attending this appointment.