Methylphenidate: what it treats, how to take it, side effects
Last updated September 3, 2026.
Methylphenidate is a central nervous system stimulant that changes the amounts of certain natural substances in the brain. You may know it as Ritalin, Concerta, or several other brands. It is the original ADHD medication and still the most prescribed - a controlled substance with real benefits and real guardrails. This page is information only - prescriptions for controlled substances always come from your own prescriber.
What does it treat?
The symptoms of ADHD - difficulty paying attention, controlling behavior, staying still or quiet - and narcolepsy, the condition of overwhelming daytime sleepiness and sudden sleep attacks.
How do you take it?
Exactly as prescribed, and the form matters: it comes as tablets, chewables, liquids, orally disintegrating tablets, and long-acting tablets and capsules, each with its own schedule. The label starts children 6 and up at 5 mg twice daily (before breakfast and lunch) for the immediate-release form, increasing by 5 to 10 mg weekly, with doses above 60 mg a day not recommended. Swallow long-acting tablets and capsules whole - never split, chew, or crush them. Peel the orally disintegrating tablet out of its blister with dry hands and let it dissolve on your tongue. Dose increases come no more often than once a week. Your doctor may pause the medication from time to time to see if it is still needed. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: nervousness, irritability, restlessness, trouble sleeping, dizziness, loss of appetite and weight loss, stomach pain, nausea, vomiting, diarrhea, heartburn, dry mouth, headache, muscle tightness, drowsiness, uncontrollable movement of a body part, decreased sexual desire, and heavy sweating. In children, it can slow growth in height and weight - the doctor tracks this.
- Serious: fast, pounding, or irregular heartbeat, chest pain, shortness of breath, excessive tiredness, or fainting; vision changes; agitation, paranoia, believing things that are not true, or hallucinations; new motor or verbal tics; depression or abnormally excited mood; painful erections lasting over 4 hours; circulation problems in fingers and toes (numbness, color changes from pale to blue to red, unexplained wounds); and allergic reactions with facial or throat swelling. Call your doctor immediately for these.
Who should not take it?
Anyone with a history of overusing alcohol, street drugs, or prescription medications needs that on the table before starting - methylphenidate can be habit-forming, and taking too much raises the risk of overdose and death. Flag heart problems, high blood pressure, mental health conditions (depression, bipolar, psychosis), circulation problems in hands and feet, and glaucoma. It carries the class warning about psychotic or manic symptoms appearing even without prior history. Never sell or share it: it is a controlled substance, sharing is illegal, and MedlinePlus says to store it securely and keep count of what is left.
When is it an emergency?
Call 911 for chest pain, fainting, trouble breathing or swallowing, or facial or throat swelling. Hallucinations, paranoia, a painful erection over 4 hours, or blue fingers and toes mean immediate care. Any thought of harming or killing yourself means calling your 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.
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Common questions
Is methylphenidate addictive?
It can be. MedlinePlus says methylphenidate can be habit-forming and to take it exactly as directed - taking too much raises the risk of overdose and death. Taken as prescribed for ADHD under your prescriber's supervision, it works as treatment rather than a high. Any history of heavy alcohol, street drug, or prescription medication misuse must be disclosed before starting.
Will methylphenidate stunt my child's growth?
It can slow it. MedlinePlus says methylphenidate may slow children's growth in height and weight gain, and the doctor will watch growth carefully during treatment. This is why dose pauses exist - your doctor may stop the medication from time to time to see if it is still needed - and why growth checks are part of every follow-up.
Why can't I crush the Concerta or long-acting tablet?
Because the release mechanism is the product. MedlinePlus says swallow long-acting tablets and capsules whole - do not split, chew, or crush them. Crushing a long-acting stimulant dumps the entire day's dose at once, which is exactly the overdose pattern the habit-forming warning is about.
Can I drink alcohol while taking methylphenidate?
Neither the label nor MedlinePlus gives a blanket alcohol ban, but MedlinePlus tells you to disclose any history of heavy drinking before starting, and mixing a stimulant with alcohol masks how impaired you actually are. Bring it up with your prescriber - the honest answer depends on your dose, timing, and history.
Why does my doctor pause the medication sometimes?
To check it is still earning its place. MedlinePlus says your doctor may tell you to stop taking methylphenidate from time to time to see if the medication is still needed. ADHD needs change with age, school, and workload - the pause is a planned reassessment, not a punishment.
What happens if I miss a dose of methylphenidate?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. With long-acting morning doses, taking a forgotten dose late in the day usually costs you a night's sleep, so late afternoon is a genuine reason to skip.