MigraineActive ingredient
Sumatriptan
Serotonin 5-HT1B/1D receptor agonist (triptan)1 FDA label read
Sumatriptan, sold as Imitrex, is the oldest medication in this category and the reference point for acute migraine treatment. This page is built from the tablet label; the label itself is explicit about what the tablets are not for: not prevention, and not cluster headache.
Highlights of the labels
- Imitrex tablets
- Acute treatment of migrainecovers migraine
- Supply
- Prescription only
- Generic
- 11 approved applications
- Boxed warning
- None in these labels
Brands and what each one is approved for
One active ingredient can hold several separate FDA approvals. They are different documents with different approved uses, and mixing them up is the most common mistake made about these medications.
| Brand | What its label approves | Supply | Label version |
|---|---|---|---|
| Imitrex tabletsGlaxoSmithKline LLC | What its label approvesAcute treatment of migraineCovers migraine | SupplyPrescription | Label version9 December 2025 |
How it works
Sumatriptan binds with high affinity to serotonin 5-HT1B/1D receptors. Its label presumes the therapeutic effect in migraine comes through that binding - wording from an era when mechanisms were stated with more caution than today.
Mechanism of action, Imitrex tablets label
Sumatriptan binds with high affinity to human cloned 5‑HT 1B/1D receptors. Sumatriptan presumably exerts its therapeutic effects in the treatment of migraine headache through agonist effects at the 5‑HT 1B/1D receptors on intracranial blood vessels and sensory nerves of the trigeminal system, which result in cranial vessel constriction and inhibition of pro‑inflammatory neuropeptide release.
What the FDA approved it for
The approved uses, as worded in the label.
- Safety and effectiveness of IMITREX tablets have not been established for cluster headache. IMITREX is a serotonin (5-HT 1B/1D) receptor agonist (triptan) indicated for acute treatment of migraine with or without aura in adults.
- Use only if a clear diagnosis of migraine headache has been established.
- Not indicated for the prophylactic therapy of migraine attacks.
- Not indicated for the treatment of cluster headache.
Forms and strengths
The presentations and strengths listed in the label.
- 25-mg Tablets: White, triangular-shaped, film-coated, and debossed with "I" on one side and "25" on the other.
- Each tablet contains 70 mg of sumatriptan succinate equivalent to 50 mg of sumatriptan. 100-mg Tablets: Pink, triangular-shaped, film-coated, and debossed with "IMITREX 100" on one side and a chevron shape (^) on the other.
- Each tablet contains 140 mg of sumatriptan succinate equivalent to 100 mg of sumatriptan.
- Tablets: 25 mg, 50 mg, and 100 mg
How the label says it is taken
What the label states about administration. It is not a dosing instruction for any individual.
- Single dose of 25-mg, 50-mg, or 100-mg tablet.
- A second dose should only be considered if some response to the first dose was observed. Separate doses by at least 2 hours.
- Maximum dose in a 24-hour period: 200 mg.
- Maximum single dose should not exceed 50 mg in patients with mild to moderate hepatic impairment. Dosing Information The recommended dose of IMITREX tablets is 25 mg, 50 mg, or 100 mg. Doses of 50 mg and 100 mg may provide a greater effect than the 25-mg dose, but doses of 100 mg may not provide a greater effect than the 50-mg dose. Higher doses may have a greater risk of adverse reactions.
Most common adverse reactions
The adverse reactions the label reports as most common.
Most common adverse reactions (≥2% and >placebo) were paresthesia, warm/cold sensation, chest pain/tightness/pressure and/or heaviness, neck/throat/jaw pain/tightness/pressure, other sensations of pain/pressure/tightness/heaviness, vertigo, and malaise/fatigue.
Warnings and precautions
The warnings and precautions section of the label.
- Myocardial ischemia/infarction and Prinzmetal's angina: Perform cardiac evaluation in patients with multiple cardiovascular risk factors.
- Arrhythmias: Discontinue IMITREX if occurs.
- Chest/throat/neck/jaw pain, tightness, pressure, or heaviness: Generally not associated with myocardial ischemia; evaluate for coronary artery disease in patients at high risk.
- Cerebral hemorrhage, subarachnoid hemorrhage, and stroke: Discontinue IMITREX if occurs.
- Gastrointestinal ischemic reactions and peripheral vasospastic reactions: Discontinue IMITREX if occurs.
- Medication overuse headache: Detoxification may be necessary.
- Serotonin syndrome: Discontinue IMITREX if occurs.
- Seizures: Use with caution in patients with epilepsy or a lowered seizure threshold. Myocardial Ischemia, Myocardial Infarction, and Prinzmetal's Angina The use of IMITREX tablets is contraindicated in patients with ischemic or vasospastic CAD.
Contraindications
Situations in which the label states the medication must not be used.
- History of coronary artery disease or coronary artery vasospasm
- Wolff-Parkinson-White syndrome or other cardiac accessory conduction pathway disorders
- History of stroke, transient ischemic attack, or hemiplegic or basilar migraine
- Peripheral vascular disease
- Ischemic bowel disease
- Uncontrolled hypertension
- Recent (within 24 hours) use of another 5-HT 1 agonist (e.g., another triptan) or of an ergotamine-containing medication
- Concurrent or recent (past 2 weeks) use of monoamine oxidase-A inhibitor
Drug interactions
Interactions the label singles out.
- Ergot-Containing Drugs Ergot-containing drugs have been reported to cause prolonged vasospastic reactions.
- Because these effects may be additive, use of ergotamine-containing or ergot-type medications (like dihydroergotamine or methysergide) and IMITREX tablets within 24 hours of each other is contraindicated. Monoamine Oxidase-A Inhibitors MAO‑A inhibitors increase systemic exposure by 7-fold.
- Therefore, the use of IMITREX tablets in patients receiving MAO‑A inhibitors is contraindicated. Other 5-HT 1 Agonists Because their vasospastic effects may be additive, coadministration of IMITREX tablets and other 5‑HT 1 agonists (e.g., triptans) within 24 hours of each other is contraindicated.
Pregnancy and breastfeeding
The opening of the pregnancy section of the label. The full section is longer and is in the source document.
Data from a prospective pregnancy exposure registry and epidemiological studies of pregnant women have not detected an increased frequency of birth defects or a consistent pattern of birth defects among women exposed to sumatriptan compared with the general population (see Data). In developmental toxicity studies in rats and rabbits, oral administration of sumatriptan to pregnant animals was associated with embryolethality, fetal abnormalities, and pup mortality.
Generic or brand
Generic sumatriptan is long established: the register lists 11 approved generic applications for the tablets. A combination product with naproxen is a separate approval with its own label.
The FDA label database lists 11 approved generic applications for this ingredient.
What affects the cost
With generics on the register for decades, the gap between the Imitrex brand price and the generic price is wide, and the table below shows both. This site sells nothing and links to no sellers.
What pharmacies pay for it
These are acquisition costs: what pharmacies in the United States pay on average to buy the medication, published weekly by the Centers for Medicare and Medicaid Services. They are not retail prices and not what a person pays at the counter, which depends on insurance, pharmacy and discount programs. They are useful as an objective floor and for seeing how far a brand sits above its generic.
| Measured | Brand | Generic |
|---|---|---|
| per tablet, capsule or pen | Brand$72.40 (range $72.30 to $72.53, 34 listings) | Generic$0.337 (range $0.251 to $21.10, 1625 listings) |
| per milliliter | Brand$461.39 (range $435.96 to $463.78, 96 listings) | Generic$15.06 (range $14.35 to $75.82, 478 listings) |
Median of 2233 listings. Effective dates 2025-12-17 to 2026-08-19, file dated 2026-08-26.
Compared with other medications
What the labels do not do is compare one medication against another. These pages put two of them side by side.
Common questions
- Why can't some people take Imitrex?
- The label's contraindication list is long and mostly cardiovascular: history of coronary artery disease or vasospasm, stroke or transient ischemic attack, peripheral vascular disease, ischemic bowel disease, uncontrolled hypertension, Wolff-Parkinson-White syndrome, recent use of another triptan or ergotamine, and monoamine oxidase-A inhibitor use, among others. The full list is quoted on this page.
- How are the tablets dosed?
- A single dose of 25, 50 or 100 mg. The label says a second dose should only be considered if some response to the first was observed, separated by at least 2 hours, with a maximum of 200 mg in 24 hours.
- Does Imitrex prevent migraines?
- No. The label states it is not indicated for prophylactic therapy of migraine, and that safety and effectiveness have not been established for cluster headache for the tablets.
Other medications under migraine
Whether each one carries an FDA approval for this use is marked on its page and in this list.
Sources
Every fact above comes from one of these documents. The date is the effective date of the label version this page was built from.
FDA prescribing information for Imitrex tablets
GlaxoSmithKline LLC. Label version 24, effective 9 December 2025.
Each stripe is one section of the label, each division in a stripe one entry in that section.
Page last updated 29 August 2026
Compiled by the HealthyStudy editorial team from FDA source documents. No medical reviewer is credited on this page, because none reviewed it.