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 smart a move as this signing is, and as overdue as Arsenal have been for a truly elite striker, bringing in Lacazette won’t be what makes or breaks Arsenal’s season. The most important move (or non-move) of the Gunners’ summer is whatever ends up happening with Sánchez. (And to a lesser extent Mesut Özil, since it seems pretty clear that the German will stick around.) Arsenal’s Chilean star is one of the very best players in the entire league, and they have to keep him if they have any hope of making this upcoming season the season when they finally make a serious title challenge.