Adderall is a combination of Amphetamine and dextroamphetamine. You can easily Buy Adderall Online. Adderall is used for treating ADHD (attention deficit hyperactivity disorder) and narcolepsy. It works by changing the amounts of several chemicals in the brain. Amphetamine and dextroamphetamine are stimulants that increase your ability to pay attention, stay focused on an activity and control behaviour problems.