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.
Oxymetholone (also known as anapolon or anadrol) is a very drastic synthetic steroid, 17-alpha-alkylated modification of dihydrotestosterone. It was developed for the treatment of osteoporosis and anaemia, as well as to stimulate muscle gain in malnourished and debilitated patients. Oxymetholone has been approved by the American Food and Drug Administration (FDA) for use in humans. Later there where created non-steroidal drugs that effectively could treat anaemia and osteoporosis; because of this anapolon lost his popularity and by 1993 Syntex decided to cease the production of the drug, as well as other manufacturers did.