Sumatriptan is used to ease the symptoms of migraine or cluster headaches. It works by releasing a natural chemical called serotonin, which causes the blood vessels around your brain to contract (narrow). This reverses the dilating (widening) of blood vessels that's believed to be part of the headache process.
Sumatriptan only works when a migraine attack has already begun. It won't prevent a migraine. Don't take it before your headache begins, or during the aura phase, as it may be less effective. Read more about migraine headaches.
In Aotearoa New Zealand, sumatriptan is available as an injection and tablets. The information on this page is about sumatriptan injection. Read more about sumatriptan tablets.
Note: From 1 November 2023, there will be a brand change. Clustran injection will be replacing Imigran injection. Find out more about the brand change.