The only way to increase testosterone with TRT is by using injectable testosterone by way of intramuscular injection (in the muscle of the buttocks) (hghinjections.us)
For tracer injections, birds were anaesthetized by intramuscular injection of ketamine (Pfitzer, Freiburg, Germany) / rompun (Bayer, Leverkusen, Germany), and their heads were fixed in a custom - built stereotactic apparatus. (journals.plos.org)
Furthermore, the constant release of intramuscular triglycerides into the bloodstream from elevated cortisol may lead to weight gain and obesity. (acefitness.org)