Strattera side effects: quick, practical guide

Strattera (atomoxetine) can help with ADHD symptoms, but it also brings side effects some people notice right away. Most are mild and fade in a few weeks, but a few are serious and need prompt care. Here’s a clear breakdown so you know what to watch for and what to do.

Common and usually mild side effects

These are the side effects people report most often. They usually start in the first days to weeks and often improve with time or a dose change:

- Nausea, upset stomach, constipation or dry mouth.

- Decreased appetite and weight loss, especially in kids. Providers often check growth and weight regularly.

- Trouble sleeping or feeling tired during the day.

- Headache, dizziness, and light increases in heart rate or blood pressure.

- Mood changes like irritability. If mild, your prescriber may wait to see if it settles; if worse, call them.

Serious warnings and when to call your doctor

These are less common but need fast action. Stop the medicine and seek help if you notice: sudden chest pain, fainting, severe shortness of breath, or a very fast or irregular heartbeat. Those can be signs of a serious heart problem.

Watch for jaundice (yellow skin or eyes), dark urine, or persistent stomach pain—these may mean liver injury. Also, atomoxetine carries a well-documented risk of increased suicidal thoughts in children and teens. If a child or teen starts talking about self-harm, becomes suddenly worse, or shows new aggressive or withdrawn behavior, contact emergency services or the prescriber immediately.

Other important safety points: avoid starting Strattera within 14 days of an MAOI drug. Some antidepressants that block CYP2D6 (for example fluoxetine or paroxetine) raise atomoxetine levels and may need dose changes or closer monitoring.

If side effects are bothersome but not dangerous, your doctor may lower the dose, space doses, or switch medications. Never change dose on your own.

Practical tips to reduce side effects: take Strattera with food to help nausea, take it in the morning to reduce insomnia, and report any weight change in children. Have baseline checks for blood pressure and heart rate before starting, and repeat them if you have a heart condition or start a drug that interacts.

Overdose signs can include vomiting, agitation, very fast heart rate, or drowsiness—call Poison Control or emergency services right away.

If you have questions about symptoms you’re experiencing, call your prescriber. Quick reporting helps them adjust treatment safely and keeps you moving forward with care that fits your life.