See below and TU paper above.
4 ml oil injection…i will pass:
The PK profile of serum testosterone and its two bioactive metabolites, DHT and E2 in this study indicate that the SC injections of TU displayed no significant differences from the IM route. This is consistent with PK studies of other steroids such as cortisol [19] and hydroxyprogesterone caproate [20] whereas in other studies the SC route displayed a lower and later peak serum concentration of progesterone [21] or medroxyprogesterone acetate [22]. Although Food and Drug Administration-defined bioequivalence was not formally tested, the two routes can be considered clinically comparable without the need for route-based dose adjustment. This interpretation differs from previous studies of SC injections which inferred a reduced testosterone dosage requirement by the SC route compared with the IM route [7, 10, 11] based on noncomparative studies of transgender men that did not investigate IM injections contemporaneously and relied upon historical data from other studies. Those studies used inconsistent, mostly single, sampling time points with the testosterone dosage being up-titrated according to clinical efficacy criteria, e.g., menstrual suppression [10], that may not represent effective virilization dosage for hypogonadal men [11].
Results
Fourteen transgender males (mean age, 30 ± 10 years) participated in the study. The mean hemoglobin values at the first and final visits were 160 ± 9 and 153 ± 9 g/L, respectively (p > 0.05); the mean ALT values were 18 ± 6 and 21 ± 10 IU/L (p > 0.05). Total testosterone exposure was comparable with subcutaneous versus i.m. injection (mean AUC, 1.7 ± 0.6 nmol·days/L/mg versus 1.9 ± 0.6 nmol·days/L/mg; p > 0.05). Information collected via weekly questionnaires indicated that the subcutaneous route was more tolerable, with lower self-reported scores for preinjection anxiety, pain during injection, and postinjection pain.
Conclusion
The subcutaneous route for the injection of testosterone was well tolerated and appeared to be as effective as i.m. injection in delivering equivalent TST levels, although there was wide intrapatient and interpatient variability.
Evidence Acquisition
Systematic review of available literature on SC testosterone administration including clinical trials, case series, and case reports. We also review the pharmacology of testosterone absorption after SC administration.
Evidence Synthesis
Available evidence, though limited, suggests that SC testosterone therapy in doses similar to those given via IM route results in comparable pharmacokinetics and mean serum testosterone levels. With appropriate training, patients should be able to safely self-administer testosterone esters SC with relative ease and less discomfort compared with the IM route.