Adderall is a combination drug containing salts of the two enantiomers of amphetamine, a psychostimulant of the phenethylamine class. Adderall is prescribed in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It is also used as an athletic performance and cognitive enhancer, and recreationally as an aphrodisiac and euphoriant. By salt content, the active ingredients of Adderall are 75% dextroamphetamine salts (the dextrorotary or 'right-handed' enantiomer) and 25% levoamphetamine salts (the levorotary or 'left-handed' enantiomer).

Adderall increases the activity of the neurotransmitters norepinephrine and dopamine in the brain, which results from its interactions with trace amine associated receptor 1 (TAAR1) and vesicular monoamine transporter 2 (VMAT2). Adderall shares many chemical and pharmacological properties with the human trace amine neurotransmitters, especially phenethylamine and N-methylphenethylamine, the latter being an isomer of amphetamine that is produced within the human body.

Adderall is generally well-tolerated and effective in treating the symptoms of ADHD. The most common side effects are cardiovascular, such as irregular heartbeat (usually manifesting as tachycardia, i.e. a fast heartbeat), and psychological, such as euphoria or anxiety. Much larger doses of Adderall are likely to impair cognitive function and induce rapid muscle breakdown (rhabdomyolysis). Drug addiction is a serious risk of Adderall abuse, but only rarely arises from medical use. Very high doses can result in a psychosis (e.g., delusions and paranoia) which rarely occurs at therapeutic doses even during long-term use. Recreational doses are generally much larger than prescribed therapeutic doses, and carry a far greater risk of serious side effects.