A large number of individuals suffer from migraine headaches. Several theories attempt to explain migraine etiology. One such theory holds that since environmental stimuli are well known to trigger migraine headaches, the pineal gland may be involved in migraine etiology. Specifically, a pineal gland irregularity may be the physical origin of migraine headaches, with subsequent physiological changes being secondary. Research has found the pineal hormone melatonin is low in migraine patients. Additionally, several studies found administering melatonin to migraine sufferers relieved pain and decreased headache recurrence in some cases. It has been suggested melatonin may play an important therapeutic role in the treatment of migraines and other types of headaches, particularly those related to delayed sleep phase syndrome. Current research supports the hypothesis that migraines are a response to a pineal circadian irregularity in which the administration of melatonin normalizes this circadian cycle; i.e., melatonin may play a role in resynchronizing biological rhythms to lifestyle and subsequently relieve migraines and other forms of headaches. In addition, research testing the administration of melatonin found it safe in migraine sufferers, with few or no side effects. However, a larger, randomized control trial is needed to definitively determine if administration of melatonin to migraine patients is effective.