Boldenone greatly stimulates hematopoiesis. Elevated levels of red blood cells improve oxygen delivery to the muscles. This makes this steroid attractive not only for bodybuilders, but also for track and field athletes. Among bodybuilders, Boldenone is appreciated not only for his ability to promote lean and dense muscle growth, but also for its peculiarity to significantly raise appetite and promote has an incredibly long active life, requiring less frequent injections and is often used as a part of very long cycles.
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.
Testosterone aromatizes very easily and therefore estrogen buildup and side effects can become an issue for users sensitive to these problems or those choosing to use a high dose of this compound. Therefore, when using Testosterone, bodybuilders often choose in incorporate an anti-estrogen such as Anastrozole, Proviron, Tamoxifen to help keep estrogen related side effects to a minimum. Extremely sensitive users, or users using very high doses (800-1200mgs) might find that stronger anti-estrogens such as Letrozole or Exemestane are more suitable. Androgenic side effects such as oily skin are also possible while taking Testosterone.