Amphetamine/dextroamphetamine is a prescription stimulant medication used to treat ADHD and narcolepsy. Sold under the brand name Adderall (among others), it contains a specific blend of amphetamine salts in a 3:1 ratio of dextroamphetamine to levoamphetamine. It’s classified as a Schedule II controlled substance, meaning it has recognized medical uses but also a high potential for abuse.
What’s Actually in the Medication
The name “amphetamine/dextroamphetamine” refers to a combination of four different amphetamine salts: dextroamphetamine saccharate, amphetamine aspartate monohydrate, dextroamphetamine sulfate, and amphetamine sulfate. These aren’t four entirely different drugs. They’re variations of the same core molecule, amphetamine, which exists in two mirror-image forms: dextroamphetamine (the “right-handed” version) and levoamphetamine (the “left-handed” version).
The combination tilts heavily toward dextroamphetamine at a 3:1 ratio. This matters because the two forms affect the brain differently. Dextroamphetamine is more potent at increasing focus and attention, while levoamphetamine has a stronger effect on the body’s fight-or-flight system. The blend is designed to provide both cognitive and physical effects in a specific balance.
How It Works in the Brain
Amphetamine/dextroamphetamine increases the levels of two key chemical messengers in the brain: dopamine (involved in motivation and reward) and norepinephrine (involved in alertness and attention). But it doesn’t simply trigger more production of these chemicals. Instead, it works through a more unusual mechanism.
The drug enters nerve cells by hitching a ride on the same transport proteins that normally recycle dopamine and norepinephrine back into the cell. Once inside, it does two things. First, it forces those transport proteins to run in reverse, pumping dopamine and norepinephrine out of the cell and into the space between neurons. Second, it gets inside the tiny storage compartments (vesicles) where these chemicals are kept, disrupts their internal chemistry, and causes the stored supply to leak out into the cell body, where it can then be pushed outward.
The result is a flood of dopamine and norepinephrine into the gaps between neurons, far beyond what normal brain signaling would produce. In people with ADHD, whose baseline levels of these chemicals in certain brain regions tend to be lower, this correction helps restore the ability to focus, control impulses, and stay on task.
What It’s Prescribed For
The FDA has approved amphetamine/dextroamphetamine for two conditions: ADHD and narcolepsy. For ADHD, it’s used in children as young as three, adolescents, and adults. For narcolepsy, a condition that causes sudden, uncontrollable episodes of falling asleep, it helps maintain wakefulness during the day.
ADHD is by far the more common reason it’s prescribed. The medication reduces the core symptoms of the disorder: inattention, hyperactivity, and impulsivity. Most people notice effects within the first day of taking it, though finding the right dose usually takes a few weeks of gradual adjustment.
Immediate-Release vs. Extended-Release
The medication comes in two main formulations. Immediate-release tablets start working in about 30 to 45 minutes and last roughly 3 to 6 hours. Because they wear off relatively quickly, most people take them two or three times a day.
Extended-release capsules (Adderall XR, Mydayis) are designed to last 8 to 12 hours with a single morning dose. They contain two types of beads: one that dissolves immediately and another that dissolves hours later, creating a second wave of medication. This eliminates the need for a midday dose and provides more consistent symptom control throughout the day.
Typical Dosing
For children ages 6 to 12 starting the extended-release version, the typical starting dose is 10 mg once daily in the morning, with increases of 5 to 10 mg per week as needed. The maximum recommended dose for children is 30 mg per day. Adolescents ages 13 to 17 also start at 10 mg, with the option to increase to 20 mg after one week. Adults starting treatment for the first time typically begin at 20 mg per day.
These are starting points. The right dose varies widely between individuals and is adjusted based on how well symptoms improve and how tolerable any side effects are.
Common Side Effects
The most frequently reported side effects are decreased appetite, weight loss, dry mouth, difficulty sleeping, nervousness, and headache. Appetite suppression is particularly common, which is why the medication can slow growth in children when used over long periods. Many providers monitor height and weight regularly in younger patients.
The stimulant effect typically raises blood pressure by about 2 to 4 mmHg and heart rate by about 3 to 6 beats per minute on average. For most healthy people this is insignificant, but it can matter for those with underlying heart conditions.
Less common but more serious side effects include mood changes, increased anxiety, teeth grinding, and in rare cases, psychotic symptoms like hallucinations or paranoia. These are more likely at higher doses or in people with a personal or family history of psychiatric conditions.
Serious Risks and Warnings
The FDA’s most prominent warning on this medication addresses its potential for abuse and addiction. As a Schedule II controlled substance, it sits in the same regulatory category as oxycodone and fentanyl in terms of abuse potential. Misuse, particularly at high doses or through non-oral routes like snorting, carries a risk of overdose and death.
The second major warning involves cardiac risk. Sudden death has been reported in patients with structural heart defects or serious heart disease who took stimulants at standard doses. People with known heart abnormalities, serious arrhythmias, coronary artery disease, or cardiomyopathy should not take this medication.
Who Should Not Take It
Beyond heart conditions, several other situations make this medication unsafe:
- MAO inhibitors: Taking amphetamine/dextroamphetamine within 14 days of using an MAO inhibitor (a type of antidepressant) can trigger a dangerous spike in blood pressure.
- Moderate to severe high blood pressure: The medication’s effect on blood pressure can worsen hypertension.
- Overactive thyroid: Hyperthyroidism already increases heart rate and metabolism, and adding a stimulant compounds the risk.
- Glaucoma: The medication can increase pressure inside the eye.
- History of drug abuse: Given its high addiction potential, it’s contraindicated in people with a substance use history.
- Agitated states: In people already experiencing significant anxiety or agitation, stimulants can make symptoms worse.
How Long It Stays in Your System
Amphetamine is primarily processed by the liver and eliminated through the kidneys. One important factor that affects how quickly it leaves the body is the acidity of your urine. More acidic urine speeds up excretion, while more alkaline urine slows it down. This means that diet, certain medications, and even conditions that change urinary pH can meaningfully alter how long the drug’s effects last and how quickly it clears from your system.