Many men report increased energy levels and improvements in mood, quality of erection and sex drive after undergoing testosterone hormone injections, according to WebMD. In some men, testosterone treatment increases muscle mass, bone density and sensitivity to insulin.
Patients with low libido, erectile dysfunction, hair loss, lack of energy and moodiness may benefit from testosterone injections, states WebMD. Patients should only undergo testosterone treatment if their measured testosterone levels are below normal. Patients should not take testosterone supplements to replace low levels due to aging or if they are not experiencing symptoms.
As of 2015, there are no long-term studies on the effects of testosterone replacement therapy, and experts believe that it can exacerbate some conditions, such as prostate cancer and blood clots, according to WebMD.