Melatonin: The Myths and Facts

Courtney Ratzburg

Outline: Click on the section you wish to go to

What is being said about melatonin
Melatonin and Sleep
Melatonin and Jet Lag
Melatonin and the Immune System
Melatonin and Age-Related Disorders
Melatonin and sleeping disorders
Melatonin and Jet Lag
Conclusions on Melatonin

Melatonin is a hormone produced in the pineal gland. The pineal gland is about the size of a pea and is located in the center of the brain ( Melatonin is secreted at night or in the dark ( It is used to regulate the sleeping cycle. It is also found to correlate with a lot of other functions and problems in the body. Because of its many uses, melatonin is being manufactured by pharmaceutical companies as a dietary supplement. People are using it to treat everything from jet lag to cancer. There have been many studies done on the effects of melatonin. The bulk of the studies have been done on the effects of melatonin on sleep and on treating jet-lag. The findings show that melatonin is proven to be an effective sleep aid and also help alleviate jet lag.

Melatonin is a substance that the public is taking without being knowledgeable about its benefits, side or dosage. Many companies manufacture melatonin. There are two kinds of melatonin available, synthetic or natural. It is recommended to take the synthetic time release formula. It is the closer to the molecular make-up of melatonin and is made with pharmaceutical grade ingredients. Natural melatonin may contain animal parts through which viruses and diseases can be carried (

What is being said about melatonin

Melatonin and Sleep

Melatonin is used most frequently for sleeping troubles and jet-lag. By differing the amount of exposure to lightness and darkness, there is a possibility of abrupting the sleep/wake cycle. It is believed this change results from varying levels of melatonin being produced. Taking melatonin is thought to induce sleep. It is found to work best when taken between twenty to forty minutes before bedtime. Low levels of melatonin seem to impede or disrupt sleep ( Without rising levels of melatonin in the evening, it is difficult to fall asleep ( The peak of melatonin production appears to be at 2:00 a.m. Melatonin levels rise when the sun goes down and decrease after 2:00a.m. ( By taking melatonin tablets before bedtime, one can supplement their melatonin levels, making sleep come more easily and sleeping more consistently.

Melatonin and Jet Lag

Melatonin is also used to relieve jet-lag. Jet lag occurs after experiencing rapid, long distance travel through different time zones. Other behaviors that produce symptoms similar to jet lag are working all night shifts, staying up all night and working multiple shifts. All of these behaviors upset the biological clock. Through upsetting the biological clock, a person may experience fatigue, dizziness, loss of ability to think clearly or a headache ( The use of melatonin before bedtime is said to help reset your biological clock, therefore relieving symptoms (

Melatonin and the Immune System

It is thought that much repair of the immune system occurs at night, therefore interacting with melatonin. When people are exposed to frequent artificial light and they do not get enough sleep melatonin levels are suppressed. Some forms of cancer are thought to be related to melatonin levels. ôMelatonin levels of breast and prostate patients are reduced to half the normal levels.ö ( In two cases of sarcoidosis, which were not responding to long term treatments, melatonin was used. In between four to five months of being treated with 20mg daily, the symptoms were alleviated (

Melatonin and Age-Related Disorders

Melatonin levels are found to decline with age, leading scientists to believe that lack of melatonin brings about age related disorders. Among the diseases that melatonin is thought to effect are Alzheimer's disease, glucose intolerance, impaired immune function and cancer ( In studies done on rats and mice, melatonin was found to increase their life-span by about 20% ( There have not been any studies completed on melatonin related to the prolonging of the human life span What studies have proven about melatoninThere have been many studies done on the effects of melatonin on the body over the past few years. Melatonin is most frequently used for the treatment of sleeping problems and in curing jet-lag. Therefore, most studies that have been done on melatonin have been done in these two subject areas. Studies have been done linking melatonin as a cure for other disorders, but there have not been enough studies available to show substantial evidence in melatonin curing other disorders.

Melatonin and sleeping disorders

By differing the amount of exposure to lightness and darkness, there is a possibility of abrupting the sleep/wake cycle. It is shown this change results from varying levels of melatonin being produced. There have been many studies done on the effect that melatonin has on sleep in hopes of treating sleep related disorders. There have not been many products manufactured that do not have a ôhang overö effect and make users feel tired in the morning. Melatonin might be the answer. Many elderly have sleeping disorders whether they are healthy or unhealthy (Garfinkel, Laudon, Nof, & Zisapel, 1995). Garfinkel, Lauden, Nof and Zisapel (1995) did a randomized, double bind, crossover study in which they regulated the sleep quality of 12 elderly people. The melatonin used in the study was controlled release melatonin. Some of the participants were given 2 mg of melatonin for three weeks. Others were given a placebo for three weeks. There was a great improvement in the sleep of those who took the melatonin in comparison to those who took the placebo. The time it took for the subjects to fall asleep was decreased dramatically. The time it took them to wake up was also significantly shorter. All of the subjects were found before hand to have a melatonin deficiency. With the extra grams of melatonin, they slept through the night quite efficiently. This study has lead researchers to believe that the replacement of melatonin in elderly people could increase their ability to sleep. No significant side effects were noted. Elderly people with sleeping problems should look into the benefits of melatonin.

J. E. Jan and other researchers (1994) did a study on the sleeping disorders in children with severe sleep disorders. Most of the subjects were disabled and melatonin was their last hope of giving themselves and their families rest. The fifteen subjects were given 2 to 5 mg or the placebo at bedtime for seven to ten days. The study was a randomized, double-blind, crossover study. The melatonin had a positive effect on most of the children. The phase setting action of melatonin seemed to achieve the desired effects. Some responded after the first dose. Most benefited by the third dose. There were not any side effects noted. The subjects did not have any hangover effects. The researchers found an improved mood in the children. Melatonin has a positive role in the relief of chronic sleep disorders.

Zhdanova (1995) conducted a study of healthy males with normal sleeping habits to determine the effects of melatonin on their sleeping patterns. The study was a double-blind placebo controlled experiment in three phases. All of the males were drug free, did not smoke and had an average diet. The average age of the subject was 26 years old. Zhdanova found that there was a large difference between the effects of melatonin and the placebo. The subjects who had the melatonin took a shorter time to fall asleep than those who had the placebo. The subjects fell asleep around 40 minutes faster than they usually did. The size of the dosage did not seem to matter. The lower dosages of melatonin worked as well as the larger ones. The dosage worked at 1 mg. The best time to administer the dosage was around an hour before bedtime. The subjects did not find any negative side-effects. The melatonin worked well in all cases.

Melatonin and Jet Lag

Claustrat (1992) conducted a study to see how melatonin alleviated jet-lag . It was a double-blind study on healthy volunteers flying from North America to France who were abnormally sensitive to jet-lag. The subjects took either 8 mg of melatonin or a placebo. The study concluded that melatonin helped to alleviate jet-lag on eastern bound flights. Some of the subjects did experience adverse side-effects though. There were a few cases a headache, and feeling drowsy later. In comparison with the placebo, the effects were positive. The subjects experienced a better mood, had an easier time falling asleep and were efficient the morning after their travel. Though there were a few side effects, the results on a whole were positive.

Lino (1993) conducted a study of the effects of melatonin on jet-lag. He recommends that melatonin be taken at 11 p.m. local time. His subjects all experienced positive results. They traveled from Hong Kong to Rome and from Rome to Hong Kong. The subjects were all medical doctors. They all received 5 mg of melatonin. Lino found out that doses of melatonin taken a few days in advance were not needed and only produced negative side-effects. These side-effects included headaches and a hang-over feeling.

Conclusions on Melatonin

Is melatonin safe? Melatonin is one of the least toxic substances known ( The only side effects related with taking a large amount of melatonin are continued drowsiness and a slower reaction time ( . Many people are discouraged from taking melatonin. People with the symptoms of severe mental illness, severe allergies, auto-immune diseases, or immune system cancers such as leukemia should not be taking melatonin. It is also not recommended during pregnancy or for women who want to conceive ( There have not been many significant studies done with this drug. While it appears to be safe, melatonin has not yet been approved by the Food and Drug Administration.

A normal question with any dietary supplement is how much should someone take? There is no answer for this question. One study suggests that a 1.5mg dosage at bedtime would be the best ( The appropriate dose can vary enormously form person to person ( One doctor has administered doses ranging from .1 mg to 200 mg, and has seen results both ways ( Another researcher suggests to begin melatonin treatment with one mg before bedtime. If it does not aid in falling to sleep, increase the dosage. If a user wakes up feeling fatigued or hung over, decrease the dosage ( It is agreed upon that it should be taken before bedtime.

Melatonin is a new discovery. It has yet to go through the extensive studies which most hormones and other dietary supplements go through. It seems to have many positive effects on the body. Distributors of the drug are making all kinds of unproved claims. Advertisements claim that melatonin enhances your sex life, helps you exhibit more energy and assists you in gaining muscle ( Caution is recommended when taking melatonin. Dr. Wurtman says of melatonin, "These pills are being sold without certification by the Food and Drug Administration, and this worries me terribly." He goes on to say "We've purchased melatonin from some health food stores and checked the purity. These tablets are not pure. People should not take melatonin for the time being except under controlled research conditions." ( Melatonin is a substance that could be very useful in many treatments once the right research has been done. Many manufacturers are making a lot of money off of people who do not know what they are taking. Melatonin is at a very experimental stage right now.

Many studies have been done on melatonin's effects on the sleep cycle and on jet-lag. Most of the studies have shown positive results. The individuals experienced very few negative side-effects and found themselves in a better mood because they were well rested. The best dosage of melatonin is yet to be found. Very high doses in women (300mg) have been known to cause some ovarian problems. Too much melatonin can leave the subject drowsy and unalert. It is best to start with a small dosage and slowly increase the dosage until it reaches the desired effects. It is not recommended for anyone who has sever mental illness, severe allergies, auto-immune diseases, or immune system cancers.

hough melatonin seems safe at the moment, it is the new ômiracleö drug that advertisers claim can cure almost anything. The public should use caution and educate themselves on any drug and its effects before they take it. This caution should be used with melatonin.


Claustrat, B., Brun, J., David, M., Sassolas, G., & Chazot, G. (1992).

Melatonin and Jet Lag: Confirmatory Result Using a Simplified

Protocol. Biological Psychiatry, 32, 705-711.

Garfinkel, D., Laudon, M., Nof, D., & Zisapel, N. (1995). Improvement of

sleep quality in elderly people by controlled-release melatonin. The

Lancet, 346, 541-543.

Jan, J. (1994). The Treatment of Sleep Disorders With Melatonin.

Developmental Medicine and Child Neurology, 36, 97-107.

Lino, A., Silvy, S., Condorelli, L., & Rusconi, A. (1993). Melatonin and Jet

Lag: Treatment Schedule. Biological Psychiatry, 34, 587.

Zhdanova, I. (1995). Sleep - inducing effects of low doses of melatonin

ingested in the evening. Clinical Pharmacology & Therapeutics, 57,



Psychology Department

The Health Psychology Home Page is produced and maintained by David Schlundt, PhD.

Vanderbilt Homepage | Introduction to Vanderbilt | Admissions | Colleges & Schools | Research Centers | News & Media Information | People at Vanderbilt | Libraries | Administrative Departments | Medical 

  Return to the Health Psychology Home Page
  Send E-mail comments or questions to Dr. Schlundt


Search: Vanderbilt University
the Internet

  Help  Advanced

Tip: You can refine your last query by searching only the results by clicking on the tab above the search box

Having Trouble Reading this Page?  Download Microsoft Internet Explorer.