Yes, you can buy Adderall for stuttering and ADHD. It is an FDA-approved medication; which stimulant composed of amphetamine and dextroamphetamine. It works on the central nervous system and reduces impulsive behavior. Adderall depends on several factors, including your age, metabolism, medication dosage, and other medications you may be taking. Generally, Adderall can be detected in the body for up to 72 hours after last use. In rare cases, it could be detected for up to a week.