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.
When used as an ancillary, it can be taken by male athletes and bodybuilders all throughout their cycle length at 50 – 100mg per day, as there is no limit to how long it can be utilized for. Some individuals prefer to also run Proviron as a PCT (Post Cycle Therapy) drug in order to reduce Estrogen levels and boost fertility. Although this can be done, there are much better compounds with similar (and stronger) effects for PCT. When the risk of even weak endogenous Testosterone suppression is thrown into the mix with Proviron, it is advised to avoid the use of Proviron for PCT purposes unless there are no other options available. During a period in which individuals are attempting to recover their natural endogenous Testosterone levels, any threat no matter how minimal to endogenous Testosterone production should be unwelcome and avoided at all costs.