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.
Clemens was one of the most accomplished pitchers in baseball history when he was accused of doping. Clemens won seven Cy Young awards, an American League MVP award, and two World Series titles, but all of that was called into question after Canseco's 2005 book accused him of using amphetamines, anabolic steroids, and human growth hormone during his career, though he was never suspended from the game. He was also named in the 2007 Mitchell Report, although he has consistently and unconditionally denied the allegations that he used steroids, including in testimony to a Congressional committee in 2008. Clemens was later indicted on perjury charges in 2010 and tried in court, but was found not guilty of perjury in 2012. Clemens has claimed that hard work helped him dominate the majors into the latter stages of his career, and not .