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.
The legal status of anabolic steroids varies from country to country. In the ., anabolic steroids are listed as Schedule III controlled substances under the Controlled Substances Act , which makes the possession of such substances without a prescription a federal crime punishable by up to seven years in prison.  In Canada, anabolic steroids and their derivatives are part of the Controlled drugs and substances act and are Schedule IV substances, meaning that it is illegal to obtain or sell them without a prescription. However, possession is not punishable, a consequence reserved for schedule I, II or III substances. Those guilty of buying or selling anabolic steroids in Canada can be imprisoned for up to 18 months. Importing or exporting anabolic steroids also carry similar penalties.  Anabolic steroids are also illegal without prescription in Australia,  Argentina, Brazil, and Portugal,  and are listed as Schedule 4 Controlled Drugs in the United Kingdom.
Pub. L. 101–647, title XIX , § 1903, Nov. 29, 1990 , 104 Stat. 4853 , as amended by Pub. L. 108–358 , § 2(c), Oct. 22, 2004 , 118 Stat. 1663 , provided that: “(a) Drugs for Treatment of Rare Diseases.— If the Attorney General finds that a drug listed in paragraph (41) of section 102 of the Controlled Substances Act (as added by section 2  of this Act) is— “(1) approved by the Food and Drug Administration as an accepted treatment for a rare disease or condition, as defined in section 526 of the Federal Food, Drug , and Cosmetic Act ( 21 . 360bb ); and “(2) does not have a significant potential for abuse, the Attorney General may exempt such drug from any production regulations otherwise issued under the Controlled Substances Act as may be necessary to ensure adequate supplies of such drug for medical purposes. “(b) Date of Issuance of Regulations.— The Attorney General shall issue regulations implementing this section not later than 45 days after the date of enactment of this Act [ Nov. 29, 1990 ], except that the regulations required under section 3(a) [former 1903(a)] shall be issued not later than 180 days after the date of enactment of this Act.”