Atomoxetine: what it treats, how to take it, side effects
Last updated September 3, 2026.
Atomoxetine is the non-stimulant option for ADHD - a selective norepinephrine reuptake inhibitor, not a controlled substance. You may know it as Strattera. It raises norepinephrine levels in the brain to control behavior, works around the clock rather than in a daily curve, and carries its own serious warning about suicidal thinking in children and teenagers.
What does it treat?
ADHD in children and adults - increasing the ability to pay attention and decreasing impulsiveness and hyperactivity, as part of a total treatment program. It is the standard alternative when stimulants are a bad fit: substance-use history, tic disorders, intolerable stimulant side effects, or a household that cannot manage a controlled substance.
How do you take it?
Once a day in the morning, or twice a day in the morning and late afternoon or early evening, with or without food, same times every day. The label doses by weight: children and adolescents under 70 kg start at 0.5 mg/kg daily toward a target of 1.2 mg/kg; those over 70 kg and adults start at 40 mg daily toward 80 mg, with 100 mg the maximum. Swallow capsules whole - never open, chew, or crush them, and if one breaks, wash the powder away and keep it out of your eyes. Patience matters: some improvement may come in the first week, but the full benefit can take up to a month. Do not stop without talking to your doctor. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: heartburn, nausea, vomiting, loss of appetite and weight loss, constipation, stomach pain, gas, dry mouth, excessive tiredness, dizziness, headache, mood swings, decreased sex drive or ability, difficulty urinating, painful or irregular periods, muscle pain, sweating, hot flashes, unusual dreams, and burning or tingling in hands, arms, feet, or legs.
- Serious: fast or pounding heartbeat, chest pain, shortness of breath, dizziness or faintness, slow or difficult speech, weakness or numbness of an arm or leg, and liver injury - yellowing skin or eyes, dark urine, itching, upper right stomach pain, or unexplained flu-like symptoms mean calling the doctor immediately. The boxed warning: children and teenagers taking atomoxetine were more likely to think about killing themselves than those not taking it. Watch behavior daily, especially at the start and at dose changes - withdrawal, hopelessness, new or worsening depression, agitation, panic attacks, irritability, aggression, impulsivity, and any talk of self-harm mean calling the doctor right away.
Who should not take it?
Anyone who has taken an MAO inhibitor like isocarboxazid, phenelzine, selegiline, or tranylcypromine within the past two weeks, and anyone with narrow-angle glaucoma or a pheochromocytoma history per the label. Tell your doctor about any family history of depression, bipolar disorder, or suicide attempts, and about seizures, liver disease, heart problems, and high blood pressure. Many medications interact - review everything with your doctor and pharmacist before starting, stopping, or changing anything. Pregnancy and breastfeeding need a direct call with your doctor.
When is it an emergency?
Call 911 for chest pain, fainting, or stroke signs like one-sided weakness or garbled speech. Yellowing skin or eyes with dark urine or itching means immediate care. Any thought of a child or adult harming or killing themselves means calling the doctor right away, or call or text 988, the Suicide and Crisis Lifeline, any time. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
Illustrative example, not a real member's messages.
Common questions
How is atomoxetine different from Adderall or Ritalin?
It is not a stimulant and not a controlled substance. Atomoxetine is a selective norepinephrine reuptake inhibitor that builds up over weeks and works around the clock, while stimulants act the same day and wear off by evening. That means no habit-forming risk and no secure-storage rules - but also no instant effect, and its own warning set.
How long does atomoxetine take to work?
MedlinePlus says you may notice improvement in the first week, but it may take up to one month to feel the full benefit. Dose increases come after at least 3 days, then again after 2 to 4 weeks. Judge it at the month mark, not the week mark.
What is the suicide warning about?
The boxed warning: studies showed children and teenagers with ADHD taking atomoxetine were more likely to think about killing themselves than those not taking it. MedlinePlus says to watch behavior daily - especially at the start and at dose changes - for withdrawal, hopelessness, new or worsening depression, agitation, aggression, and any talk of self-harm, and to call the doctor right away if they appear. Teachers and siblings who see the child daily should know to report changes too.
Why can't I open the atomoxetine capsule?
The powder inside is not meant for skin or eyes. MedlinePlus says swallow capsules whole - do not open, chew, or crush them - and if a capsule breaks, wash the loose powder away with water right away and rinse your eyes immediately if any gets in. It is a handling rule, not just a release-mechanism rule.
Can I drink alcohol while taking atomoxetine?
Neither the label nor MedlinePlus lists a specific alcohol interaction for atomoxetine. Given its liver-injury warning and the dizziness it can cause, most clinicians suggest keeping alcohol light and watching how you respond - raise it with your prescriber.
Is atomoxetine a good option if stimulants did not work for me?
That is exactly its lane. Because it works through norepinephrine rather than the stimulant pathway, it is the standard alternative when stimulants fail, cause intolerable side effects, or are ruled out by a substance-use history or tic disorder. The trade is patience: weeks to full effect, and stomach upset early on.