This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Sumatriptan is a medicine to treat migraines and cluster headaches. It does not prevent these conditions.
It's not fully understood what causes migraines and cluster headaches, but it may be due to the temporary widening of blood vessels in your brain. Sumatriptan works by narrowing these blood vessels again.
You'll usually take or use sumatriptan once a migraine or cluster headache has started. It is not a painkiller but you can use this medicine if painkillers or non-steroidal anti-inflammatory drugs (NSAIDs) have not worked.
Sumatriptan comes as tablets, a nasal spray or injection. The nasal spray and injection are used to treat migraines and cluster headaches. The tablets are for migraines only.
Sumatriptan is available on prescription. You can also buy packs containing two, 50mg tablets from a pharmacy without a prescription, but only if you have previously been diagnosed with migraines.
View the original NHS website page ↗. Refreshed 19 August 2026.
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