Designer steroids. A particularly dangerous class of anabolic steroids are the so-called designer drugs — synthetic steroids that have been illicitly created to be undetectable by current drug tests. They are made specifically for athletes and have no approved medical use.ome athletes take straight testosterone to boost their performance. Frequently, the anabolic steroids that athletes use are synthetic modifications of testosterone. These hormones have approved medical uses, though improving athletic performance is not one of them.