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 . 
As you become more experienced in the implementation and maintenance of steroids cycles, you may find that you’re ready to try your hand at the best steroids stacks. These are multiple products used in conjunction with each other for both expedited and enhanced results. Stacking is only for seasoned bodybuilders who have a clear understanding of how these products affect their bodies. Even the very best steroid stack can have a host of adverse effects if you aren’t ready for the stress that this system causes. Thus, it’s generally best to run several bulking and cutting cycles using standalone products before attempting to implement the best steroid stacks.