Imigran/Sumatriptan Tablets

Migraine is a neurological condition that affects millions of people in the UK, often causing severe, debilitating headache alongside nausea, vomiting, and sensitivity to light and sound. Sumatriptan tablets, available as the branded product Imigran and as generic sumatriptan, are a triptan medicine used for the acute treatment of migraine, with or without aura.

Sumatriptan is one of the most studied and widely used medicines in migraine management. The 100 mg strength requires a prescription; the 50 mg strength is available as a Pharmacy Medicine following pharmacist assessment.

Sumatriptan tablets are an oral prescription medicine belonging to the triptan class of antimigraine medicines. The active ingredient is Sumatriptan succinate. Imigran is the originator brand manufactured by Haleon; generic Sumatriptan tablets from other manufacturers are also widely available.

Sumatriptan is licensed in the UK for the acute treatment of migraine attacks, with or without aura, in adults. It is not for prevention of migraine. It treats migraine episodes as they occur and works most effectively when taken early in an attack.

Sumatriptan should only be taken when a migraine headache phase has started; it is not effective when taken during the aura phase before headache begins.

Sumatriptan is available in two tablet strengths: 50 mg and 100 mg. It is also available as a nasal spray and as a subcutaneous injection (auto injector), which are separate products. This page covers the oral tablet formulations only.

Sumatriptan relieves migraine by targeting specific serotonin receptors involved in the mechanisms that cause migraine pain.

5-HT1B/1D Receptor Agonism

Sumatriptan is a selective agonist (activator) of 5-HT1B and 5-HT1D serotonin receptors. Activation of 5-HT1B receptors in the walls of the cranial blood vessels causes vasoconstriction, narrowing the dilated intracranial arteries that contribute to the throbbing pain of a migraine attack. Activation of 5-HT1D receptors on trigeminal nerve terminals reduces the release of neuropeptides that cause neurogenic inflammation and pain signal transmission in the trigeminal nerve pathway. Together these two actions address two of the core mechanisms responsible for migraine pain.

Central and Peripheral Effects

Sumatriptan also inhibits pain signal transmission at the level of the trigeminal nucleus caudalis in the brainstem. This central action, combined with its peripheral effects on cranial blood vessels and trigeminal nerve terminals, gives Sumatriptan its antimigraine efficacy. Because Sumatriptan acts on the mechanisms specific to migraine, it is not effective for other types of headache such as tension headache.

The onset of action after an oral dose is typically within 30 to 60 minutes. The effect on headache relief is well established in clinical trials. Sumatriptan is effective for migraine with and without aura, though it should be taken once the headache phase has begun rather than during the preceding aura.

Always take Sumatriptan exactly as your prescriber or pharmacist instructs. The information below summarises key points from the current UK SmPC. Read the Patient Information Leaflet supplied with your medicine before taking it.

• Take Sumatriptan as soon as possible after a migraine headache begins. It works best when taken early in the headache phase.
• Do not take it during the aura (visual or sensory symptoms that may precede headache); wait until the headache itself starts.
• Swallow the tablet whole with water.
• The usual starting dose is 50 mg. If 50 mg does not provide adequate relief, 100 mg may be more effective in future attacks. Your prescriber or pharmacist will advise on the appropriate dose.
• If the first dose provides partial or no relief, do not take a second dose for the same attack. Sumatriptan is not effective as a rescue dose once the first dose has failed in the same attack.
• If the headache initially improves but then returns, a second dose may be taken for the recurrent headache, provided at least two hours have passed since the first dose.
• Do not take more than 300 mg of Sumatriptan in any 24-hour period (a maximum of three 100 mg tablets or six 50 mg tablets).
• Do not take Sumatriptan on more than 10 days in any calendar month. Overuse of any acute headache medicine, including triptans, can cause medication overuse headache, a chronic daily headache condition.
• Sumatriptan can be taken with or without food.
• Lie down in a darkened quiet room after taking your dose, if possible, as rest can help the medicine to work.
• If your migraine is accompanied by nausea or vomiting and you have difficulty keeping the tablet down, speak to your prescriber about alternatives such as the Sumatriptan nasal spray.

Sumatriptan 50 mg Tablets

The 50 mg tablet is the recommended starting dose for most adults. In UK clinical practice, 50 mg is often tried first. If 50 mg does not provide relief for a given attack, your prescriber or pharmacist may recommend trying 100 mg in subsequent attacks.

Sumatriptan 50 mg tablets are classified as a Pharmacy Medicine (P) in the UK and may be obtained following a pharmacist assessment without a prescription, subject to the pharmacist's judgement that the medicine is appropriate for the patient.

Sumatriptan 100 mg Tablets

The 100 mg tablet is a higher dose option for patients who find 50 mg provides insufficient relief. Clinical studies show that 100 mg may be more effective than 50 mg in some patients.

The 100 mg tablet is a Prescription Only Medicine (POM) in the UK and requires a valid prescription.

The maximum dose in any 24-hour period is 300 mg. All dose decisions are made by your prescriber or pharmacist. Do not take a higher dose than recommended.

Like all medicines, Sumatriptan can cause side effects. The information below is based on the current UK SmPC. Refer to the Patient Information Leaflet for the full list.

Common Side Effects (may affect up to 1 in 10 people)

• Sensations of warmth, tingling, heaviness, pressure, or tightness, often described as "triptan sensations". These can affect the chest, neck, limbs, or face and are typically transient.
• Flushing.
• Dizziness.
• Fatigue or tiredness.
• Nausea and vomiting.
• Pain, heaviness, or pressure in the throat.

Important: Chest Symptoms

Some patients experience tightness, pain, or pressure in the chest after taking sumatriptan. In most cases these sensations are not cardiac in origin and are related to the vasoconstriction mechanism of the medicine. However, Sumatriptan should not be used in patients with known or suspected cardiovascular disease, and any new or worsening chest symptoms during treatment should be assessed medically. If you experience severe chest pain or tightness, stop taking Sumatriptan and seek urgent medical attention.

Serious Side Effects: Seek Urgent Medical Attention

Go to your nearest accident and emergency department or call 999 immediately if you experience:

• Severe chest pain or tightness that could indicate a cardiac event. Sumatriptan causes vasoconstriction and must not be used in patients with known cardiovascular disease.
• Signs of a stroke such as sudden weakness on one side of the body, sudden difficulty speaking, or sudden severe headache different from your usual migraine.
• Signs of serotonin syndrome: agitation, confusion, rapid heart rate, high blood pressure, muscle twitching, loss of coordination, or high temperature. This is a rare but serious interaction, most likely when Sumatriptan is combined with other serotonergic medicines.
• Signs of a severe allergic reaction such as sudden swelling of the face, lips, tongue, or throat, or difficulty breathing.

Report any suspected side effect to your prescriber, pharmacist, or via the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk.

Sumatriptan Tablets May Be Suitable If You:

• Are an adult aged 18 to 65 with a confirmed diagnosis of migraine (with or without aura).
• Have migraine attacks that have not been adequately relieved by standard analgesics such as paracetamol or ibuprofen.
• Do not have any of the cardiovascular, cerebrovascular, or vascular contraindications listed below.

Sumatriptan Tablets Are Contraindicated If You:

• Have a history of myocardial infarction (heart attack), ischaemic heart disease, coronary artery vasospasm (including Prinzmetal's angina), or any other significant cardiovascular disease.
• Have had a stroke or transient ischaemic attack (TIA).
• Have peripheral vascular disease.
• Have uncontrolled hypertension.
• Have hemiplegic, basilar, or ophthalmoplegic migraine.
• Are under 18 or over 65 years of age. Clinical trial data is limited in these age groups.
• Are taking an ergotamine containing medicine or another ergot derivative (such as dihydroergotamine). Do not take Sumatriptan within 24 hours of ergotamine preparations or vice versa.
• Are taking another triptan medicine. Do not take two different triptans within 24 hours of each other.
• Are taking a monoamine oxidase inhibitor (MAOI) or have taken one within the previous two weeks.
• Have severe hepatic or severe kidney impairment.
• Are pregnant (unless a prescriber judges the benefit outweighs the risk). Discuss with your prescriber before taking Sumatriptan during pregnancy.
• Have a known allergy or hypersensitivity to Sumatriptan or any excipient listed in the SmPC.

Tell your prescriber about all medicines you take. Key interactions for Sumatriptan include:

• Ergotamine and ergot derivatives: the combination with Sumatriptan is contraindicated due to an additive vasoconstrictive effect. Allow at least 24 hours between ergotamine and Sumatriptan in either direction.
• Other triptans: do not combine different triptan medicines or take them within 24 hours of each other.
• MAOIs: contraindicated. The combination with Sumatriptan increases Sumatriptan blood levels and the risk of serious adverse effects.
• SSRIs, SNRIs, and other serotonergic medicines: combined use with Sumatriptan may increase the risk of serotonin syndrome. Monitor for symptoms of serotonin syndrome if these medicines are taken together.
• St John's Wort: may increase the risk of serotonergic side effects.

Your prescriber or pharmacist will review your current medicines before Sumatriptan is supplied.

For Sumatriptan 100 mg, a clinical consultation is the essential first step. A prescription will only be issued if a registered prescriber concludes, based on their individual assessment of your circumstances, that Sumatriptan 100 mg is clinically appropriate for you.

During your online consultation with Pharmacy Planet, a registered prescriber will review the information you provide. This includes your migraine history, cardiovascular health, current medicines, blood pressure history, and any history of stroke or TIA. Sumatriptan has significant cardiovascular contraindications, and the prescriber will assess your individual risk profile carefully before any prescription is issued.

For Sumatriptan 50 mg as a Pharmacy Medicine, a pharmacist assessment covers similar clinical questions. The pharmacist will confirm that migraine has been previously diagnosed by a healthcare provider, that the current symptoms match your typical migraine pattern, and that there are no contraindications.

Not all consultations will result in a prescription. The prescriber may determine that Sumatriptan is not appropriate given your cardiovascular history, recommend a different triptan or approach to migraine management, or advise that a face-to-face consultation with your GP is needed. This process is designed to protect your safety.

Store below 30°C. Store in the original packaging to protect from light and moisture. Keep out of the sight and reach of children. Do not use after the expiry date printed on the packaging. Do not dispose of medicines via household waste or wastewater. Return unused or out of date tablets to your pharmacist for safe disposal. Full storage instructions are provided in the Patient Information Leaflet supplied with your medicine.

Pharmacy Planet is a GPhC-registered online pharmacy providing access to prescription medicines through a clinically led consultation process. Our registered prescribers and pharmacists are committed to patient safety, clinical accuracy, and responsible prescribing. We follow GPhC standards, MHRA guidance, and ASA advertising regulations in all aspects of our service. Every prescription is reviewed and dispensed by qualified healthcare professionals.

We provide clear, factual information to help patients understand their migraine management options and make informed decisions about acute migraine therapy. If you have questions about sumatriptan, Imigran, or any other medicine, our pharmacy team is available to help. We are committed to transparent, patient centred care.

References

1. Electronic Medicines Compendium (eMC). Imigran 50 mg and 100 mg tablets — Summary of Product Characteristics. https://www.medicines.org.uk/emc. Accessed May 2026.
2. National Institute for Health and Care Excellence (NICE). Headaches in over 12s: diagnosis and management. NICE guideline CG150. https://www.nice.org.uk/guidance/cg150. Accessed May 2026.
3. NHS. Sumatriptan. https://www.nhs.uk/medicines/sumatriptan. Accessed May 2026.
4. Joint Formulary Committee. British National Formulary (BNF). Sumatriptan. BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk. Accessed May 2026.
5. Medicines and Healthcare products Regulatory Agency (MHRA). Yellow Card — report a side effect. https://yellowcard.mhra.gov.uk. Accessed May 2026.

Triptan Tablets for Acute Migraine

The table below compares commonly prescribed triptan tablets available at Pharmacy Planet. All three of the medications listed below treat acute migraine attacks. Key differences lie in starting dose, the propranolol interaction (rizatriptan), the moclobemide and cimetidine interaction (zolmitriptan), and the Sumatriptan 50 mg Pharmacy Medicine status.

Important: This comparison is for general information only and does not replace medical advice. A prescriber will decide which treatment is suitable for you following an online consultation.