These are synthetic derivatives of testosterone; a hormone that occurs naturally in the body controlling many functions. Among these functions is the promoting of anabolism. Steroids mimic this natural occurring event and have the ability to do so at an accelerated rate. Though the exact means by which steroids exert their effects is still somewhat of a mystery, some aspects are known for certain. Once anabolic steroids are in the blood, they bind to androgen receptor sites. Then they enter the cell, just like the endogenous hormone would, and alter the function of that cell. After changes in DNA and RNA patterns, an increased rate of protein synthesis is observed.