Zomig relieves migraine headaches. It's effective whether or not the headache is preceded by an aura (visual disturbances such as halos and flickering lights). For most people Zomig provides relief within 2 hours, but it will not abort an attack or reduce the number of headaches you experience.

Migraines are thought to be caused by expansion and inflammation of blood vessels in the head. Zomig ends a migraine attack by constricting these blood vessels and reducing inflammation.