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 . 
SARMs ( Selective Androgen Receptor Modulators ) are performance enhancers which have been used in competitive sports for some time. According to the many users of SARMS in the world of steroids, they are used because they are oral in nature and they target androgen receptors in the body effectively. The fact that they have to be ingested is a plus for Selective Androgen Receptor Modulators, since they take a short time to reach the bloodstream. SARMS are the most highly abused steroids in the world of sports and since they are cheaper and more effective a lot of drug companies are making them for the black market. According to users, the problem with other steroids is that they have their own unique limitations as they will cause the fluctuation of testosterone levels in the bloodstream. Androgenic effects of using SARMS are noticed immediately after they have been used. It is for this reason that it has been used for the treatment of osteoporosis in women. SARM is one of the few of its kind not to cause liver damage in its users. Most oral steroids have been modified to protect them from being damaged by the liver when it is being ingested and most of them cause a lot of liver problems due to this.