Sumatriptan is used to treat migraines. It helps to relieve headache, pain, and other migraine symptoms (including nausea, vomiting, sensitivity to light/sound). Prompt treatment helps you return to your normal routine and may decrease your need for other pain medications. Sumatriptan belongs to a class of drugs known as triptans. It affects a certain natural substance (serotonin) that causes narrowing of blood vessels in the brain. It may also relieve pain by affecting certain nerves in the brain. Sumatriptan does not prevent future migraines or lessen how often you get migraine attacks.