Not all steroids are created equal. In fact, the word steroid encompasses hormones that are so different, it can drive you downright crazy trying to sort them all out. For example, birth-control pills for women are steroid hormones, but you won't get muscular by taking them. Cortisone is another type of steroid that will, in fact, make you lose muscle.

Fenfluramine is an appetite suppressant, and phentermine increases the metabolism. Yet this combination of drugs poses significant health risks, including pulmonary hypertension and brain damage.