Testosterone can be administered parenterally , but it has more irregular prolonged absorption time and greater activity in muscle in enanthate , undecanoate , or cypionate ester form. These derivatives are hydrolyzed to release free testosterone at the site of injection; absorption rate (and thus injection schedule) varies among different esters, but medical injections are normally done anywhere between semi-weekly to once every 12 weeks. A more frequent schedule may be desirable in order to maintain a more constant level of hormone in the system.  Injectable steroids are typically administered into the muscle, not into the vein, to avoid sudden changes in the amount of the drug in the bloodstream. In addition, because estered testosterone is dissolved in oil, intravenous injection has the potential to cause a dangerous embolism (clot) in the bloodstream.
While the adrenal glands still help out with testosterone and progesterone production in later years, the amount supplied is extremely small. The biggest issue that we see is an end to normal estrogen levels when the body converts excess testosterone into estradiol. This causes an imbalance that leads to a condition called estrogen dominance – where estrogen is now unopposed by progesterone and testosterone because their levels have declined. Estrogen dominance leads to weight gain, which further increases testosterone to estrogen conversion.
– The heart palpitations that ive had for a year are gone, (Heart beating really hard/increased awareness of it in upper body, neck and head)
– Slowing of heart rate
– Extreme reduction in anxiety similar to Valium and or Phenibut. (More similar to phenibut without the stimulated feeling pheni has)
– Euphoria (pronounced, not like a drug but my depression is gone and i cant force myself to think negative at all)
– General well being and reduction in fatigue (I have diagnosed CFS/ME)