The drug treatment (P/T) × visibility (observed/private) × recipient (other/self) effect on the extracted free parameters was analyzed using GzLMMs analogous to the analysis of the correct choice. We tested candidate models with a single learning rate (Rescorla-Wagner models) as well as models with dual learning rates. In essence, RLDDM bridges RL, which typically models choices, and DDM, which commonly models response times (RT). To uncover the cognitive computational processes underlying our learning task, we performed modeling analysis under the joint reinforcement learning drift diffusion model (RLDDM) framework 24, 41. The relationship between mean serum total testosterone and SC testosterone dose is shown in Fig. Horizontal dashed lines represent the lower and upper limits of the normal male range for total and free testosterone. The median (range) interindividual CV for serum total testosterone was 37.2% (25.6% to 51.7%) and the intraindividual CV was 20.2% (7.0% to 30.4%). We confirmed with this patient and all others that they did not take any testosterone (injection or otherwise) in addition to the injections prescribed at 7-day intervals. Dashed lines represent the lower and upper values of normal range for each total free testosterone. These metabolites also bind hormone receptors with varying affinities, contributing to the hormone’s diverse biological actions. Concurrently, testosterone undergoes metabolic conversion primarily in the liver, involving reduction to dihydrotestosterone (DHT) via 5α-reductase and aromatization to estradiol by aromatase enzymes. This ligand-receptor interaction initiates transcriptional regulation of androgen-responsive genes, mediating physiological effects such as muscle anabolism and secondary sexual characteristics. The primary testosterone benefits include improved muscle mass, enhanced bone density, cognitive function stabilization, and mood regulation. We show that exogenous testosterone fully eliminated strategic, i.e., feigned, prosociality and thus decreased submission to audience expectations. Rival theories suggest that the hormone might either diminish or strengthen audience-dependent prosociality. Injection schedules directly influence travel and lifestyle flexibility by affecting injection portability and frequency. However, individual pricing may vary based on medication type, dosage, and healthcare provider fees, necessitating personalized financial assessment for optimal cost-effectiveness within testosterone therapy protocols. Clinicians must balance efficacy, side effect profiles, and patient convenience to tailor protocols effectively. However, daily protocols may reduce injection comfort due to increased frequency, potentially impacting adherence. The present data also shows that testosterone administration substantially alters the relation between the audience effect and self-reported value orientations. However, we did not observe any interaction of the testosterone’s effect with cortisol levels measured at baseline or with cortisol reactivity, thus our data do not provide support for such an interpretation. However, our data do not indicate that testosterone affects exploration in general, as we did not find any testosterone influence on choice consistency in the private setting. In all models, we simultaneously modeled participants’ choice and RT, separately for each between-subject condition (i.e., placebo/testosterone; observed/private). The testosterone dose and timing of the experiment were based on the previously established pharmacokinetic study of testosterone gel preparations in healthy young males . Those allocated to the testosterone group received a single dose of testosterone gel containing 150 mg testosterone Androgel®; participants in the placebo group received an equivalent amount of placebo gel. This evidence-based side effects comparison underscores the critical role of injection frequency in tailoring TRT regimens to balance efficacy and tolerability. Weekly injections may cause higher peak-trough fluctuations, possibly increasing risks of fluid retention and acne. This regimen aims to mimic physiological testosterone secretion more closely, potentially minimizing peaks and troughs that contribute to variable symptom control and side effects. The pharmacokinetics of injected testosterone depend on the ester formulation, influencing absorption rate, half-life, and serum concentration fluctuations. Clinical protocols emphasize individualized dosing to optimize outcomes while minimizing adverse effects, such as erythrocytosis and cardiovascular risks. Patients were required to inject doses on Mondays to allow for study draws to be completed during normal laboratory business hours (Monday through Saturday). FTM transgender patients between 18 and 50 years old already receiving SC therapy with testosterone cypionate were recruited from the Maine Medical Center outpatient Reproductive Endocrinology and Infertility clinic. Only one pharmacokinetic study of SC testosterone ester injection has been reported . Subcutaneous (SC) insertion of testosterone pellets is available but has been limited by the need for surgery, the possibility of infection, fibrosis or pellet extrusion, limited data regarding efficacy, inflexibility of dosing and limited acceptance 11, 12. Another option for IM injections, testosterone undecanoate, although administered infrequently, is painful and is available only through a risk evaluation and mitigation program because of the risk of pulmonary oil microembolism 6, 7. Furthermore, IM injections are often painful and may require administration by a trained professional, making this modality less than ideal.
