Melatonin is a hormone secreted by the pineal gland in the brain. It helps regulate other hormones and maintains the body's circadian rhythm. The circadian rhythm is an internal 24-hour “clock” that plays a critical role in when we fall asleep and when we wake up. When it is dark, your body produces more melatonin; when it is light, the production of melatonin drops. Being exposed to bright lights in the evening or too little light during the day can disrupt the body' s normal melatonin cycles. For example, jet lag, shift work, and poor vision can disrupt melatonin cycles.Melatonin also helps control the timing and release of female reproductive hormones. It helps determine when a woman starts to menstruate, the frequency and duration of menstrual cycles, and when a woman stops menstruating (menopause). Some researchers also believe that melatonin levels may be related to aging. For example, young children have the highest levels of nighttime melatonin. Researchers believe these levels drop as we age. Some people think lower levels of melatonin may explain why some older adults have sleep problems and tend to go to bed and wake up earlier than when they were younger. However, newer research calls this theory into question.Melatonin has strong antioxidant effects. Preliminary evidence suggests that it may help strengthen the immune system.InsomniaStudies suggest that melatonin supplements may help people with disrupted circadian rhythms (such as people with jet lag or those who work the night shift) and those with low melatonin levels (such as some seniors and people with schizophrenia) to sleep better. A review of clinical studies suggests that melatonin supplements may help prevent jet lag, particularly in people who cross five or more time zones.A few clinical studies suggest that when taken for short periods of time (days to weeks) melatonin is more effective than a placebo in reducing the time it takes to fall asleep, increasing the number of sleeping hours, and boosting daytime alertness. It' s not clear how well melatonin works, however – some studies suggest that it only reduces the amount of time to fall asleep by a few minutes. A number of human studies have measured the effects of melatonin supplements on sleep in healthy people. A wide range of doses has been used, often taken by mouth 30 - 60 minutes prior to sleep time. Results have been mixed. Some evidence suggests that melatonin may work best for people over 55 who have insomnia. One study of 334 people aged 55 and older found that sustained-release melatonin seemed to help people fall asleep faster, sleep better, be more alert in the morning, and improve quality of life in people with primary insomnia.Because of the potential for side effects and interactions with medications, people should take dietary supplements only under the supervision of a knowledgeable health care provider.Some people may have vivid dreams or nightmares when they take melatonin. Taking too much melatonin may disrupt circadian rhythms (your “body clock”).Melatonin can cause drowsiness if taken during the day. If you are drowsy the morning after taking melatonin, try taking a lower dose.Additional side effects include stomach cramps, dizziness, headache, irritability, decreased libido,ʙʀᴇᴀsт enlargement in men (called gynecomastia), and decreased ꜱρєɾɱ count.Pregnant or nursing women should not take melatonin because it could interfere with fertility.Some studies show that melatonin supplements worsened symptoms of depression. For this reason, people with depression should consult their doctor before using melatonin supplements.Although many researchers believe that melatonin levels go down with age, newer evidence has brought this theory into question. People older than 65 should ask their doctor before taking melatonin supplements, so blood levels of this hormone can be monitored.For more information visit: http://www.webmd.com/sleep-disorders/tc/melatonin-......
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