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Printed from the University of Maryland Medical Center website at www.umm.eduPage Title:MelatoninPage URL: http://www.umm.edu/altmed/articles/melatonin-000315.htm Home > Medical Reference > Complementary Medicine Melatonin is a hormone secreted by the pineal gland in the brain. It helps regulate other hormones andmaintains the body's circadian rhythm. The circadian rhythm is an internal 24-hour “clock” that plays a criticalrole in when we fall asleep and when we wake up. When it is dark, your body produces more melatonin; whenit is light, the production of melatonin drops. Being exposed to bright lights in the evening or too little lightduring the day can disrupt the body' s normal melatonin cycles. For example, jet lag, shift work, and poorvision can disrupt melatonin cycles.
Melatonin also helps control the timing and release of female reproductive hormones. It helps determine whena woman starts to menstruate, the frequency and duration of menstrual cycles, and when a woman stopsmenstruating (menopause).
Some researchers also believe that melatonin levels may be related to aging. For example, young childrenhave the highest levels of nighttime melatonin. Researchers believe these levels drop as we age. Somepeople think lower levels of melatonin may explain why some older adults have sleep problems and tend to goto bed and wake up earlier than when they were younger. However, newer research calls this theory intoquestion.
Melatonin has strong antioxidant effects. Preliminary evidence suggests that it may help strengthen theimmune system.
If you are considering using melatonin supplements, talk to your doctor first.
Studies suggest that melatonin supplements may help people with disrupted circadian rhythms (such aspeople with jet lag or those who work the night shift) and those with low melatonin levels (such as someseniors and people with schizophrenia) to sleep better. A review of clinical studies suggests that melatoninsupplements 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 moreeffective 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 suggestthat 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. Awide range of doses has been used, often taken by mouth 30 - 60 minutes prior to sleep time. Results havebeen 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 fallasleep faster, sleep better, be more alert in the morning, and improve quality of life in people with primaryinsomnia.
Melatonin supplements may help with sleep problems associated with menopause. However, it does notappear to relieve other symptoms of menopause, such as hot flashes. Peri- or postmenopausal women whouse melatonin supplements should do so only for a short period of time since long term effects are not known.
Some clinical research has found that melatonin may help elderly people with insomnia who are tapering off orstopping benzodiazepines such as diazepam (Valium), alprazolam (Xanax), or lorazepam (Ativan). Takingcontrol ed-release melatonin improved sleep quality in those stopping benzodiazepine use. More study isneeded.
Several studies suggest that melatonin levels may be associated with breast cancer risk. For example,women with breast cancer tend to have lower levels of melatonin than those without the disease. Laboratoryexperiments have found that low levels of melatonin stimulate the growth of certain types of breast cancercel s, while adding melatonin to these cells slows their growth. Preliminary evidence also suggests thatmelatonin may strengthen the effects of some chemotherapy drugs used to treat breast cancer. In a study thatincluded a small number of women with breast cancer, melatonin (given 7 days before beginningchemotherapy) prevented the lowering of platelets in the blood. This is a common complication ofchemotherapy that can lead to bleeding.
In another small study of women who were taking tamoxifen for breast cancer but seeing no improvement,adding melatonin caused tumors to modestly shrink in more 28% of the women. Women with breast cancershould ask their doctors before taking melatonin.
Studies show that people with prostate cancer have lower melatonin levels than men without the disease. Intest tube studies, melatonin blocks the growth of prostate cancer cel s. In one small-scale study, melatonin --combined with conventional medical treatment -- improved survival rates in 9 out of 14 men with metastaticprostate cancer. Interestingly, since meditation may cause melatonin levels to rise it appears to be a valuableaddition to the treatment of prostate cancer. More research is needed before doctors can makerecommendations in this area.
Attention Deficit Hyperactivity Disorder (ADHD) Some evidence suggests that melatonin may help promote sleep in children in ADHD, although it does notseem to improve the behavioral symptoms of ADHD.
Sunburn -- A few small clinical studies suggest that gels, lotions, or ointments containing melatoninmay protect against sunburn and other skin damage. Studies examined using melatonin alone orcombined with topical vitamin E prior to UV light exposure from the sun.
Irritable Bowel Syndrome -- Some preliminary studies suggest that people with IBS who takemelatonin reduce some symptoms of IBS, such as abdominal pain. But results are mixed as to whethermelatonin may help improve other symptoms, such as bloating and frequency of bowel movements.
Epilepsy -- Some studies suggest melatonin may reduce the frequency and duration of seizures inchildren with epilepsy. But other studies suggest melatonin may increase the frequency of seizures. Donot take melatonin for epilepsy or give it to a child without talking to your doctor first.
Melatonin is available as tablets, capsules, cream, and lozenges that dissolve under the tongue.
There is currently no recommended dose for melatonin supplements. Different people will have differentresponses to its effects. Lower doses appear to work better in people who are especially sensitive. Higherdoses may cause anxiety and irritability.
The best approach for any condition is to begin with very low doses of melatonin. Keep the dose close to theamount that our bodies normally produce (< 0.3 mg per day). You should only use the lowest amount possibleto achieve the desired effect. Your doctor can help you determine the most appropriate dose for yoursituation, including how to increase the amount, if needed.
Always ask your doctor before giving melatonin to a child. Keep doses to less than 0.3 mg/day. There isnot enough information to say that doses greater than 0.3 mg per day are safe in children under age15. In fact, doses between 1 - 5 mg may cause seizures in this age group.
Insomnia: 1 to 3 mg 1 hour before bedtime is usual y effective, although doses as low as 0.1 -0.3 mgmay improve sleep for some people. If 3 mg per night does not work after 3 days, try 5 - 6 mg 1 hourbefore bedtime. You should work with your doctor to find the safest and most effective dose for you.
The right dose for you should produce restful sleep with no daytime irritability or fatigue.
Jet lag: 0.5 - 5 mg of melatonin 1 hour prior to bedtime at final destination has been used in severalstudies. Another approach that has been used is 1 - 5 mg 1 hour before bedtime for 2 days prior todeparture and for 2 - 3 days upon arrival at final destination.
Because of the potential for side effects and interactions with medications, people should take dietarysupplements 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 maydisrupt 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, breastenlargement in men (called gynecomastia), and decreased sperm 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, peoplewith depression should consult their doctor before using melatonin supplements.
Although many researchers believe that melatonin levels go down with age, newer evidence has brought thistheory into question. People older than 65 should ask their doctor before taking melatonin supplements, soblood levels of this hormone can be monitored.
If you are being treated with any of the fol owing medications, you should not use melatonin without firstdiscussing it with your health care provider.
Antidepressant medications -- In an animal study, melatonin supplements reduced the antidepressanteffects of desipramine and fluoxetine (Prozac). More research is needed to know if the same thing wouldhappen in people. In addition, fluoxetine (a member of a class of drugs called selective serotonin reuptakeinhibitors, or SSRIs) can cause low levels of melatonin in people.
Antipsychotic medications -- A common side effect of antipsychotic medications used to treat schizophreniais a condition called tardive dyskinesia, which causes involuntary movements. In a study of 22 people withschizophrenia and tardive dyskinesia caused by antipsychotic medications, those who took melatoninsupplements had fewer symptoms compared to those who did not take the supplements.
Benzodiazepines -- The combination of melatonin and triazolam (Halcion) improved sleep quality in onestudy. In addition, a few reports have suggested that melatonin supplements may help people stop usinglong-term benzodiazepine therapy. (Benzodiazepines are habit-forming.) Blood pressure medications -- Melatonin may make blood pressure medications like methoxamine (Vasoxyl)and clonidine (Catopres) less effective. In addition, medications in a class cal ed calcium channel blockersmay lower melatonin levels. Calcium channel blockers include: Nifedipine (Procardia)Amlodipine (Norvasc)Verapamil (Calan, Isoptin) Diltiazem (Cardizem)Felodipine (Plendil)Nisoldipine (Sular)Bepridil (Vascor) Beta-blockers -- Use of beta-blockers may lower melatonin levels in the body. Beta-blockers include: Acebutolol (Sectral)Atenolol (Tenormin)Bisoprolol (Zebeta)Carteolol (Cartrol)Metoprolol (Lopressor, Toprol XL)Nadolol (Corgard)Propranolol (Inderal) Blood-thinning medications (anticoagulants) -- Melatonin may increase the risk of bleeding fromanticoagulant medications such as warfarin (Coumadin).
Interleukin-2 -- In one study of 80 cancer patients, use of melatonin along with interleukin-2 led to more tumorregression and better survival rates than treatment with interleukin-2 alone.
Nonsteroidal anti-inflammatory drugs (NSAIDs) -- NSAIDs such as ibuprofen (Advil, Motrin) may lowerlevels of melatonin in the blood.
Steroids and immunosuppressant medications -- Melatonin may cause these medication to lose theireffectiveness. Do not take melatonin with corticosteroids or other medications used to suppress the immunesystem.
Tamoxifen -- Preliminary research suggests that the combination of tamoxifen (a chemotherapy drug) andmelatonin may benefit some people with breast and other cancers. More research is needed to confirm theseresults.
Other -- Caffeine, tobacco, and alcohol can all lower levels of melatonin in the body.
Reviewed last on: 12/8/2009Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary andalternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.
Acuna-Castroviejo D, Escames G, Rodriguez MI, Lopez LC. Melatonin role in the mitochondrial function. FrontBiosci. 2007;12:947-63.
Altun A, Ugur-Altun B. Melatonin: therapeutic and clinical utilization. Int J Clin Pract. 2007;61(5):835-45.
Arendt J. Melatonin, circadian rhythms and sleep. New Engl J Med; 2000;343(15):1114-1116.
Attele AS, Xie JT, Yuan CS. Treatment of insomnia: an alternative approach.Altern Med Rev.
2000;5(3):249-259.
Barcelo E. Melatonin -- estrogen interactions in breast cancer. J of Pineal Res. 2005;38:217-222.
Barcelo E. melatonin and mammary cancer: a short review. Endocrine-Related Cancer. 2003;10:153-159.
Bazil CW, Short D, Crispin D, Zheng W. Patients with intractable epilepsy have low melatonin, whichincreases following seizures. Neurology. 2000;55(11):1746-1748.
Brown GM, Pandi-Perumal SR, Trakht I, Cardinali DP. Melatonin and its relevance to jet lag. Travel Med InfectDis. 2009 Mar;7(2):69-81. Review.
Bylesjo I, Forsgren L, Wetterberg L. Melatonin and epileptic seizures in patients with acute intermittentporphyria. Epileptic Disord. 2000;2(4):203-208.
Chang FY, Lu CL. Treatment of irritable bowel syndrome using complementary and alternative medicine. J Chin Med Assoc. 2009 Jun;72(6):294-300. Review.
Cornelissen G, Halberg F, Burioka N, Perfetto F, Tarquini R, Bakken EE. Do plasma melatonin concentrationsdecline with age? Am J Med. 2000;109(4):343-345.
Cos S, Sanchez-Barcelo EJ. Melatonin and mamary pathological growth. Frontiers Neuroendo.
2000;21:133-170.
Cos S, Sanchez-Barcelo EJ. Melatonin, experimental basis for a possible application in breast cancerprevention and treatment. Histo Histopath. 2000;15:637-647.
Eck-Enriquez K, Kiefer TL, Spriggs LL, Hil SM. Pathways through which a regimen of melatonin and retinoicacid induces apoptosis in MCF-7 human breast cancer cells. Breast Cancer Res Treat. 2000;61(3):229-239.
Gordon N. The therapeutics of melatonin: a paediatric perspective. Brain Dev. 2000;22(4):213-217.
Herxheimer A, Petrie KJ. Melatonin for preventing and treating jet lag. Cocharane Database Syst Rev.
2001;(1):CD001520.
Jacobson JS, Workman SB, Kronenberg F. Research on complementary/alternative medicine for patients withbreast cancer: a review of the biomedical literature. J Clin Onc. 2000;18(3):668-683.
Kaneko S, Okumura K, Numaguchi Y, Matsui H, Murase K, Mokuno S, et al. Melatonin scavenges hydroxylradical and protects isolated rat hearts from ischemic reperfusion injury. Life Sciences. 2000;67(2):101-112.
Lagneux C, Joyeux M, Demenge P, Ribuot C, Godin-Ribuot D. Protective effects of melatonin againstischemia-reperfusion injury in the isolated rat heart. Life Sciences. 2000;66(6):503-509.
Lewy AJ, Emens J, Jackman A, Yuhas K. Circadian uses of melatonin in humans. Chronobiol Int.
2006;23(1-2):403-12.
Low Dog T, Riley D, Carter T. Traditional and alternative therapies for breast cancer. Alt Ther.
2001;7(3):36-47.
Lusardi P, Piazza E, Fogari R. Cardiovascular effects of melatonin in hypertensive patients wel control ed bynifedipine: a 24-hour study. Br J Clin Pharmacol. 2000;49(5):423-7.
Malhotra S, Sawhney G, Pandhi P. The therapeutic potential of melatonin: a review of the science. MedscapeGeneral Medicine 2004;6(2).
Moretti RM, Marelli MM, Maggi R, Dondi D, Motta M, Limonta P. Antiproliferative action of melatonin on humanprostate cancer LNCaP cells. Oncol Rep. 2000;7(2):347-351.
Nagtagaal JE, Laurant MW, Kerkhof GA, Smits MG, van der Meer YG, Coenen AM. Effects of melatonin onthe quality of life in patients with delayed sleep phase syndrome. J Psychosom Res. 2000;48(1):45-50.
Peled N, Shorer Z, Peled E. Pillar G. Melatonin effect on seizures in children with severe neurologic deficitdisorders. Epilepsia. 2001;42(9):1208-1210.
Picciril o JF. Melatonin. Prog Brain Res. 2007;166:331-3.
Pillar G, Shahar E, Peled N, Ravid S, Lavie P, Etzioni A. Melatonin improves sleep-wake patterns inpsychomotor retarded children. Pediatr Neurol. 2000;23(3):225-228.
Ram PT, Yuan L, Dai J, Kiefer T, Klotz DM, Spriggs LL, et al. Differential responsiveness of MCF-7 humanbreast cancer cell line stocks to the pineal hormone, melatonin. J Pineal Res. 2000;28(4):210-218.
Reiter RJ. Melatonin: clinical relevance. Best Pract Res Clin Endocrinol Metab. 2003;17(2):273-85.
Sack RL, Brandes RW, Kendall AR, Lewy AJ. Entrainment of free-running circadian rhythms by melatonin inblind people. N Engl J Med. 2000;343(15):1070-1077.
Schernhammer E, Hankinson S. Urinary melatonin levels and breast cancer risk. J Nat Canc Instit2005;97(14):1084-1087.
Shamir E, Barak Y, Shalman I, Laudon M, Zisapel N, Tarrasch R, et al. Melatonin treatment for tardivedyskinesia: a double-blind, placebo-controlled, crossover study. Arch Gen Psych. 2001;58(11):1049-1052.
Shamir E, Laudon M, Barak Y, Anis Y, Rotenberg V, Elizur A, et al. Melatonin improves sleep quality of patientswith chronic schizophrenia. J Clin Psychiatry. 2000;61(5):373-377.
Simko F, Pechanova O. Potential roles of melatonin and chronotherapy among the new trends in hypertensiontreatment. J Pineal Res. 2009 Sep;47(2):127-33. Epub 2009 Jun 29. Review.
Smits MG, Nagtegaal EE, van der Heijden J, Coenen AM, Kerkhof GA. Melatonin for chronic sleep onsetinsomnia in children: a randomized placebo-controlled trial. J Child Neurol. 2001;16(2):86-92.
Srinivasan V, Spence DW, Pandi-Perumal SR, Trakht I, Cardinali DP. Therapeutic actions of melatonin incancer: possible mechanisms. Integr Cancer Ther. 2008 Sep;7(3):189-203. Review.
Stewart LS. Endogenous melatonin and epileptogenesis: facts and hypothesis. Int J Neurosci.
2001;107(1-2):77-85.
van Wijingaarden E, Savitz DA, Kleckner RC, Cai J, Loomis D. Exposure to electromagnetic fields and suicideamong electric utility workers: a nested case-control study. West J Med. 2000;173;94-100.
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