Generally, pharmacists will not refill prescriptions for controlled substances, like Adderall, before your previous prescription has run out. This means if your prescriber has prescribed you a 30 day supply of Adderall, you must wait 30 days to receive your refill. You can, of course, request to your doctor that he or she requests the refill a few days in advance. Pharmacists may work with your doctor to refill a prescription a couple days in advance, but this is not a common enough occurrence to rely on regular, and may cause issues for you down the road.