Zomig is a headache medicine that narrows blood vessels around the brain. Zomig also reduces substances in the body that can trigger headache pain, nausea, sensitivity to light and sound, and other migraine symptoms. Zomig is used to treat migraine headaches. Zomig will only treat a headache that has already begun. It will not prevent headaches or reduce the number of attacks. Zomig should not be used to treat a common tension headache, a headache that causes loss of movement on one side of your body, or any headache that seems to be different from your usual migraine headaches. Use this medication only if your condition has been confirmed by a doctor as migraine headaches.