I've taken on pill of adderall (dextroamphetamine and racemic amphetamine) (20mg) and i can't focus i've been off of it since sunday. how long until it is flushed out of my system completely?

XR?: Depends if adderall (dextroamphetamine and racemic amphetamine) or adderall (dextroamphetamine and racemic amphetamine) XR. Adderall (dextroamphetamine and racemic amphetamine) itself has a very short half life (4-6 hrs) meaning the time for half to be metabolized. XR is more like 8-12 hrs. 5 half lives means there is negligible amount left in your body so either way all of it should be gone by now if you only took one pill