Uses of Melatonin

Evidence continues to accumulate in research journals and case studies about melatonin’s effectiveness in treating many conditions. This chapter focuses on those conditions for which the use of melatonin has been well documented. The last chapter of the book will discuss uses of melatonin for which research is in the very early stages.


Up to 40% of adults endure frequent nights of inadequate sleep. As a family physician I often hear from frustrated patients about their difficulties in getting a restful night. When I give lectures or seminars on how to sleep better, countless people describe to me their anguish and despair. One young woman says that even walking past her bedroom gives her a panicky feeling. She fears her bed. She associates her bed with horrible nights of alertness in the dark.

Many insomniacs use over-the-counter medicines like Benadryl, Nyquil, or Sominex. Some try herbal products such as valerian root or sip chamomile tea.

There are many causes for inadequate or disrupted sleep (see the following table). If you suffer from insomnia, consult this list to see if any of the reasons apply to you. Take necessary steps to correct them. Follow the twenty tips to deep sleep as outlined in Chapter 9. If, after following all these steps, you continue with frequent episodes of insomnia, consult a physician to make sure you have no serious medical or psychological causes. If your exam and tests are normal, it may be appropriate to temporarily attempt the help of a sleep medicine. A good choice is melatonin.

MacFarlane, from McMaster University in Toronto, Canada, tested the effect of 75 mg of melatonin administered nightly at 10 pm to 13 insomniacs. A significant improvement in sleep and daytime alertness was observed with melatonin compared to treatment with placebo. Six of the 13 participants also reported improved mood. In some insomniacs the response to melatonin was delayed by several nights.

The dosage used to treat insomnia is quite variable. One option is to start with 1 mg 2 hours before bed. Try this for a few nights. If no improvement is noted, try 2 or 3 mg. Use this higher dosage for a few more nights. Experiment to see what hour before bedtime is right for you to take melatonin. Some people may find taking a pill several hours before bed helps them more than taking it 1 hour before. It may be trial and error until you come up with the best dosage and timing for your unique self.

There is a condition called delayed sleep phase insomnia. People with this condition cannot fall asleep at the same clock time, but have no difficulty sleeping when bedtime is delayed 2-5 hours. If bedtime the first night is 12 midnight, the following night they would sleep normally at 2 am, the night after at 4 am, and so on. Melatonin seems to be very effective for patients who have this syndrome. It resets their clock, by advancing their sleep phase. Dahlitz, from the University of London, successfully treated 8 patients with this syndrome using 5 mg of melatonin at 10 pm.

In cases of severe insomnia where a pharmaceutical pill alone is not effective, combining it and melatonin, both at low doses, may be of great benefit (Ferini-Strambi, 1993). Taking lower doses of pharmaceutical sleeping pills should reduce their side effects.

When deciding to stop the use of melatonin or any sleeping medicine, it is best to taper off over a period of 1 to 2 weeks to avoid any sleep disturbances. Melatonin may in some individuals cause rebound insomnia, as do some other sleeping pills, but to a much lesser degree. Only a small percentage of people feel any withdrawal symptoms. Marilyn, a survey participant, writes, “I stopped taking melatonin last summer after regular use and noticed no withdrawal symptoms at that time. Most recently, I have noticed that if I stop taking it after a few days (usually 3 or 4), I have more trouble falling asleep. I also wake more often during the night.”

Jerry, from Denver, notes, “I took 3 mg of melatonin for 2 months because I was going through a rough divorce. I stopped taking it last week and did not notice any withdrawal. My sleep is not as deep, but not any different than what it was before I started taking melatonin.”

Even though withdrawal is uncommon, and mild, it is still best to taper off slowly. For example, if you have been using 3 mg of melatonin regularly for a while and you feel you don’t need it anymore, lower the dose to 2 mg for a few nights, then 1 mg for another few nights, and stop.

Sleeping problems in children have also been treated successfully with melatonin supplements. James Jan, M.D., from British Columbia’s Children’s Hospital in Vancouver, Canada, has effectively treated over 90 children with insomnia due to conditions such as autism, Down’s syndrome, mental retardation, hyperactivity, neurological disabilities, benign sleep myoclonus (muscle spasm), certain types of epilepsy, and more. He reports in the March 1995 issue of Developmental Medicine and Child Neurology that no side-effects or tolerance has been found. The doses used were 2.5 mg to 10 mg, with little benefit from higher doses. Melatonin was required for two to three months, after which many of the children maintained the improved sleeping patterns without it.

Jet Lag

Symptoms of jet lag include irritability, difficulty concentrating, headache, low mood, and fatigue. The change in sleeping patterns may also contribute to temporarily lowering our immunity, making us more prone to colds and infections.

Jet lag symptoms are usually worse when traveling west to east since most people have a circadian cycle longer than 24 hours (Harma, 1993). Melatonin taken in the evening of the new time zone can provide a quick readjustment.

Should melatonin be taken a few days before a trip or on the night of arrival? In a double-blind placebo-controlled trial (Petrie, 1993), 52 members of an international cabin crew were randomly assigned to 3 groups:

The early melatonin group took 5 mg starting 3 nights prior to the flight and continued 5 nights after arrival.

The late melatonin group took placebo for 3 nights before the flight then 5 mg melatonin the night of arrival and continued for 5 nights.

The third group received placebo pills throughout the study.

The late melatonin group reported significantly less jet lag and sleep disturbance following the flight compared to placebo. The late melatonin group also showed a significantly faster recovery of energy and alertness than the early melatonin group. Surprisingly, the placebo group also did better than the early melatonin group. These findings show melatonin has potential benefits for jet lag when given on the night of arrival as opposed to starting a few nights before the trip.

What dosage of melatonin should you take? As we discussed previously, a wide range of dosages works for people. An additional factor to consider with jet lag is the hours of difference between the new time zone and the one you’re used to. The larger the difference, the more melatonin may be required. For instance, a dose of 3 mg may be required if you need to sleep 3 hours earlier while a 6 hour change may require more. No definite numbers can be given that apply to everyone. One rough estimate is to take 1 mg of melatonin for every hour difference. In other words, if you travel from the West Coast to the East, and there is a 3 hour change in time, take 3 mg. If you travel from the East Coast to Europe, and you need to sleep 6 hours earlier, take 6 mg.

When is the best time to take melatonin for jet lag? For most people, roughly 1 to 3 hours before the new desired bedtime works well. You may also consider splitting the dose. For instance, if you plan to take a total of 6 mg, use 3 mg about 2 hours and 1 hour before bed.

Melatonin can also be used for red-eye flights. Tommy Turner, a 37 year old banking consultant, tells me, “I’ve used melatonin to prevent jet lag twice. Both times I used a 2.5 mg sublingual dose. I left Atlanta a 7:30 pm and slept on the plane for 5 hours. I arrived in London the next morning, refreshed.”

Shift Work

C. Boyes, a pharmacy doctoral student in Corvallis, Oregon, writes, “I work with many people at Salem Memorial Hospital who take melatonin for shift syndrome. They love it. Many of the night shift staff use it. They take a 3 mg dose about 8 am when they get off from work and state that they begin to feel drowsy about 30 minutes later. They claim to sleep better with fewer interruptions. They wake up refreshed with no hangover. I have also seen several doctors begin to routinely order melatonin as a sleep medication for their patients. We have had no complaints from patients, no apparent side effects, and it has been effective in all of the cases so far. The only side effect I have heard of was that one night shift worker said that he had a slightly upset stomach if he didn’t take the medication with food.”

Folkard and colleagues examined the effect of melatonin supplements on sleep, mood and behavior in a small group of police officers working spans of 7 successive night shifts. Compared to placebo, and to no treatment, melatonin (5 mg) taken at the desired bedtime improved sleep, mood, and led to increased alertness during working hours.

Workers who switch to a night shift can improve their adaptation by exposing themselves to bright artificial light at night and shielding themselves from bright light during the day. Shielding can be accomplished by wearing dark goggles during daylight hours (Eastman, 1994).

Those who regularly change work shifts, such as police officers, hospital employees, and factory workers, are more likely to get sick. They report frequent colds, fatigue, low motivation, and stomach problems. Interpersonal relationships may be affected. When an employee has been used to working 9 am to 5 pm and has to change to an 11 pm to 7 am shift, tremendous stress is placed on the body. The circadian rhythm goes haywire. Hormones are not sure when to rise or when to fall. It may take up to 2 weeks or more to completely readjust to the new schedule. Melatonin supplements can accelerate the process of re-adjustment.


Sleep disturbance influences mood and daytime energy (Totterdell, 1994). Actually, we don’t need a study to tell us this, we’ve all experienced these symptoms after a long, toss-and-turn night. It’s hard to be motivated and get things done. Melatonin can improve daytime mood in those who do not normally get a good night’s sleep.

Norman, a 55 year old professor, writes, “One thing is for sure. The quality of my sleep has improved tremendously since taking 1.25 mg of melatonin nightly. Hardly ever, almost never, do I feel sleepy in the early afternoon— and this was common before I started taking melatonin. My mood is better.”
I personally notice increased energy and improved mood and alertness on the days following a great night’s sleep on melatonin.

In an interesting study, a male patient who lacked melatonin was given melatonin supplements. The patient’s pineal gland had been destroyed 5 years earlier in the course of treatment for a pineal tumor. The administration of melatonin 0.5 mg to 2 mg significantly improved his sleep and mood (Petterborg, 1991).

Every medicine has an ideal dosage. Too high doses of melatonin may make some people tired and depressed, especially those who are prone to depression. Leonard, from Vancouver, British Columbia, writes, “I’ve used melatonin and it worked quite well. I’ve had problems getting to sleep all my life. It usually takes me about 2 hours to fall asleep and the melatonin reduced that to around a half hour, a miracle for me. I used either 3 or 6 mg depending on what I felt I would need on a given night. I slept fine without the morning grogginess from other stuff I’ve used over the years. I stopped using it because I noticed that I was feeling a little depressed and I suspected the melatonin. I’ve suffered from serious depression when I was younger— suicide attempts, the whole deal. It went away about 10 years ago. When I stopped using melatonin I returned to my usual (somewhat sleep deprived but not depressed) self again. I think it’s important to look into this possible effect of melatonin. I wonder if someone has to be predisposed to depression to be affected by melatonin like I was. This experience was enough for me to give up using melatonin without regrets despite how well it worked for my insomnia.” It’s possible that Leonard’s melatonin dose was too high for him. Since he does not sleep well, he may benefit from some additional melatonin. Perhaps his ideal dose is 0.5 or 1 mg.

Low amounts of melatonin produced by our pineal gland lead to poor sleep, and consequently cause next-day tiredness and low mood. Too high doses may also have negative effects on mood.

Melatonin doses need also to be adapted to the seasons, to menstrual cycles, to the types of food we eat, to levels of exercise, and so on. A great many factors influence melatonin levels, sleepiness, and mood. You are the best person to figure out your ideal dose.

In addition to its effects on mood, melatonin can diminish anxiety and stress. It can influence the same brain receptors that benzodiazepines, such as Valium, use to provide relaxation (Pierrefiche, 1993). However, benzodiazepines interact negatively with brain receptors involved with memory. Melatonin does not interact with these receptors, and thus does not appear to interfere with memory and learning (Neville, 1986).

We’ve seen how changing the patterns of our sleep cycles through traveling and shift work can produce unpleasant consequences. Just how did these sleep cycles come about, anyway? Evolutionary secrets now revealed tell a fascinating story.

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Written by Ray Sahelian MD

Explore Wellness in 2021