Adderall is an FDA-approved stimulant medication commonly used for difficulty concentrating and narcolepsy, a sleep disorder. You can purchase Adderall online from various online pharmacies, though you should always make sure to buy from a reputable source. Before buying Adderall online, before buying Adderall your doctor to make sure it is the right medication for you. Additionally, be sure to get a prescription and have it filled at a legitimate pharmacy to ensure the safety and efficacy of your medication.