Anabolic steroids differ in their characteristics, which means there are steroids that are only suitable for specific uses. For instance, Trenbolone is not recommended for bulking but it is an outstanding fat burner. This makes it perfect for a lean mass cycle or a cutting cycle. Always take the side effects of a particular compound into consideration whenever you plan a stack. Do not combine anabolic steroids that show similar side effects. For example, never combine Anapolon and Dianabol because they are already quite toxic and if you combine them, the toxicity will increase exponentially and cause serious damage to your body.
One of the first changes made to the testosterone molecule was the addition of a methyl group or an ethyl group to the 17-carbon position. This addition was noted to inhibit the hepatic degradation of the molecule, greatly extending the molecule's half-life and making it active when administered orally. Prior to this, testosterone, dihydrotestosterone, and 19-nortestosterone all required parenteral administration due to hepatic metabolism of 17-ketosteroids; this metabolism occurred on the first pass, when the drugs were administered orally.