The most commonly used AAS in medicine are testosterone and its various esters (but most commonly testosterone undecanoate , testosterone enanthate , testosterone cypionate , and testosterone propionate ),  nandrolone esters (most commonly nandrolone decanoate and nandrolone phenylpropionate ), stanozolol , and metandienone (methandrostenolone).  Others also available and used commonly but to a lesser extent include methyltestosterone , oxandrolone , mesterolone , and oxymetholone , as well as drostanolone propionate , metenolone (methylandrostenolone), and fluoxymesterone .  Dihydrotestosterone (DHT; androstanolone, stanolone) and its esters are also notable, although they are not widely used in medicine.  Boldenone undecylenate and trenbolone acetate are used in veterinary medicine . 
In 2006 the National Institute on Drug Abuse (NIDA) released a research report on AAS abuse where they reported that there is evidence for addiction because people continue to use them despite experiencing negative health consequences . Mind you, you could say the same thing about cupcakes and Hot Pockets. However, there are negative social consequences as well. What’s more, “steroid abusers typically spend large amounts of time and money obtaining drugs, which is another indication that they may be addicted.” And although the Sports Medicine study stated withdrawal effects were rare, NIDA said such effects include mood swings, fatigue, restlessness, reduced sex drive, and cravings for steroids. Most concerning was a possibility of depression, out of fear that it could lead to suicide attempts.