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In the exact center of your brain resides a tiny organ called the pineal (pronounced "pie-NEEL") gland, which is about the size and shape of a kernel of corn. This gland produces a hormone called melatonin.

    Melatonin is one of the most versatile and potent substances in the body, a principal player in the maintenance of health and well-being in all stages of life. Not only does this amazing hormone counteract stress, fight off viruses and bacteria, improve the quality of sleep, minimize the symptoms of jet lag, and regulate biological rhythms, it may even help protect against cancer, reduce the risk of heart disease, and play a role in determining how long we live.

Melatonin Aids Sleeps

Until very recently, only two of melatonin's many roles–enhancing sleep and relieving jet lag–have been high-lighted in the media.

    The general public first learned that melatonin is a remedy for insomnia in the fall of 1993. Highly publicized results of a sleep study conducted at the Massachusetts Institute of Technology (MIT) revealed that a mere trace of melatonin–0.1 milligrams–enhanced sleep in healthy young volunteers.

    The number of people who might benefit from taking melatonin as a sleep aid is enormous. In the United States approximately one out of every four adults and two out of every four senior citizens have trouble falling asleep or staying asleep. Women as a group have more difficulty sleeping than men, partly because of the effects of menstruation, pregnancy, nursing, child care, and menopause.

    Melatonin researchers do not agree on exactly how melatonin helps people sleep. There are two possible mechanisms: (1) it may alter your circadian rhythms, shifting the time that you normally fall asleep to a more desirable time of day; and/or (2) it may have a direct sleep-inducing effect.

    Melatonin's effect on body temperature is one of the keys to its ability to enhance sleep. It has been known since 1835 that the temperature of the human body has a distinct circadian rhythm, rising during the day and falling at night. The daily swing in temperature is only about a degree, but it still has a strong influence on sleep. As a rule, it is easier to fall asleep when your body temperature is falling and to wake up when it is on the rise. Interestingly, you will fall asleep the most quickly and sleep the longest if you turn out the lights while your body temperature is dropping the most rapidly. This fall happens to coincide with the steepest rise in your nightly melatonin levels, which takes place somewhere between nine P.M. and twelve A.M., depending on your unique circadian rhythm. If you go to bed at some other point in your melatonin cycle, either earlier or later, your sleep may be neither as restful nor as long.

    Melatonin has none of the negative side effects associated with traditional sleep medications. To begin with, it does not significantly disrupt the sleep architecture. Nor does nature's sleeping pill interfere with a person's memory or performance the next day. Nor does melatonin appear to have negative side effects in the elderly.

    Another reason that melatonin is such a superlative sleep aid is that it does not lose its effectiveness over time. Benzodiazepines can become less effective after only two or three nights of use. By contrast, melatonin may become a more effective sleep aid with chronic use.

    Several studies have shown that melatonin dramatically reduces the symptoms of transmeridian travel. It helps people fall asleep more quickly once they reach their new destination and even more important, it helps adjust their biological rhythms to local time. In effect, melatonin resets the body clock to match the bedside clock, cutting in half the number of days that people suffer from jet lag.

Many Facets of Melatonin

One of melatonin's main functions is to trigger the body's nightly cycle of rest and repair. At around two or three in the morning, when your melatonin levels peak, there is a significant increase in the number of immune cells circulating in your bloodstream, enhancing your body's defenses against cancer, viruses, and bacteria.

    Melatonin also plays a vital role in boosting your immune system when you are under stress, whether that stress comes from viral infection, emotional stress, drugs that suppress the immune system, or the aging process.

    Melatonin is the most potent, versatile antioxidant there is. As a nation, Americans toss down almost a billion dollars' worth of antioxidant vitamins each year. We eat foods high in antioxidants and take antioxidant vitamins because studies have shown that they give us a wide range of health benefits, from a lowered risk of heart disease and certain cancers to a reduced incidence of cataracts. Antioxidants help protect us from disease by attacking dangerously reactive molecules called free radicals, which can cause extensive damage to the body. More than sixty diseases, from rheumatoid arthritis to herpes zoster, are now believed to be caused or exacerbated by free radicals. Antioxidants stop free radicals in their tracks, helping to preserve the integrity of our cells and protect our overall health.

    Melatonin is not just an antioxidant–it appears to be the most efficient and versatile antioxidant known. It is twice as effective as vitamin E, five times as efficient as glutathione, and five hundred times more effective than the synthetic antioxidant DMSO.

    Recent research has given us new insight into one of the body's own mechanisms for maintaining a healthy heart–the nightly production of melatonin. Melatonin lowers cholesterol and blood pressure, researchers have found, and reduces the risk of irregular heartbeat.

    Compelling new evidence suggests that melatonin plays a primary role in the body's defense against cancer. In a number of studies, when animals were protected with melatonin before being injected with a potent carcinogen cancer failed to develop.

    Melatonin may also slow the growth of cancer once it is established. Test-tube studies have demonstrated that melatonin inhibits the growth of a number of human cancer cells, including breast cancer, lung cancer, cervical cancer, melanoma, and most recently prostate cancer.

    Melatonin shows even more promise in treating cancer when it is used in combination with other therapies. In pilot studies conducted primarily in Europe, melatonin has improved the effectiveness of virtually all forms of cancer therapy, including chemotherapy, surgery, immunotherapy, and radiation. When melatonin is added to these therapies, more patients experience complete remission of their tumors than when these therapies are used alone. In addition, the majority of patients live longer, experience fewer side effects, and have a better quality of life. The clinical implications are enormous.

    Melatonin may prove to be a worthy adversary to AIDS virus. It stimulates a number of immune cells known to be deficient in AIDS patients (including T-helper cells, natural killer cells, and a vital signaling compound called interleukin-2). In addition, melatonin has the potential to protect AIDS patients from the toxic effects of frequently prescribed drugs such as AZT and to improve the quality of life of those in the final stages of the disease.

    What sets melatonin apart from virtually all other treatments for cancer and AIDS is its lack of toxicity. Hundreds of animals and human studies have shown it to be extremely safe, nontoxic, and nonaddictive hormone. In the most extensive trial to date, fourteen hundred women have been taking high doses of the hormone for over four years with little evidence of negative side effects. Dozens of smaller studies have produced similar findings. According to one knowledgeable researcher, "You'd have to drown yourself in melatonin to have it be toxic."

    Taking melatonin may extend your health, productive life span. As you age, your body produces less and less melatonin, depriving you of this sleep-enhancing free-radical-scavenging, heart-calming, immune-stimulating cancer-fighting hormone–in short, depriving you of one of your best defenses against aging. Replenishing your supply of this vital hormone may allow you to live longer and delay the onset of crippling diseases such as arthritis, diabetes, heart disease, cancer, Alzheimer's and Parkinson's. This possibility is more than wishful thinking. In laboratory studies, giving melatonin to aging animals has extended their life span by as much as 20 percent.

    The fact that a substance with so many remarkable properties is available for sale without a prescription is unprecedented in the annals of medicine. We have a great deal yet to learn about melatonin, including which doses are best for which uses and who should not be taking it.

    Our body produces very little melatonin in the daytime. If you take a melatonin tablet at the wrong time of day, you work at cross-purposes to your natural biological rhythms. Even more troubling, children produce ample amounts of melatonin on their own. Except in rare instances–and then only under a doctor's supervision–there is no reason to give children melatonin.

    Your natural supply of melatonin is vital to your health because it helps your body function the way it was designed to function. A modern lifestyle may be robbing you of this important hormone. For example, in our ignorance–and arrogance–we have constructed artificial lighting environments that alienate us from the earth's natural cycle of light and dark. This artificial lighting can wreak havoc on your production of melatonin, giving you too much melatonin in the daytime, when you want to be active and alert, and too little at night, when you need to be sleeping.

    Electromagnetic fields (EMFs)–those invisible waves of energy given off by power lines, household wiring, and electrical appliances–may also be reducing your melatonin levels, a possibility that is now being scrutinized in laboratories around the world. But the worst threat to your natural supply of melatonin may be to take one of many common prescription drugs. Drugs that have been proven to lower melatonin levels in humans include the most widely sold pain relievers, a popular anti-anxiety drug, the top-selling antidepressant, and many heart medications.

Frequently Asked Questions About Melatonin

Question: Why do people respond so differently to melatonin? I take a small dose and sleep like a log. My spouse take three times as much and notices no effect whatsoever.

Answer: Soon after it is absorbed, the melatonin from a tablet to capsule passes through your liver, where some of the hormone is converted into a related substance (6-hydroxymelatonin sulfate), which is then excreted in your urine. Some people have livers that remove most of the melatonin from circulation; as a result, even a relatively high dose of the hormone can have little effect. Others have livers that allow most of it to enter the bloodstream intact, resulting in a noticeable effect from a small dose.

There is no way of knowing in advance how you will metabolize melatonin, so you may have to find the right dose by trial and error. One physician who prescribes melatonin recommends that you start with a small dose, say 0.5 milligrams, and increase or decrease the dose as necessary. (A dose higher than 10 milligrams may result in high levels of melatonin well into the next day.)

Question: Melatonin helps me falls asleep, but often I wake up in the middle of the night and have a hard time getting back to sleep. Why is this?

Answer: Melatonin has an unusually short half-life, from 30 to 40 minutes. This means that several hours after you take melatonin, you may have negligible amounts in your bloodstream, depriving you of its sleep-enhancing effect.

Taking melatonin at bedtime can also cause you to wake up very early in the morning, even if you normally sleep soundly throughout the night. This early-morning awakening is caused by the rapid elimination of melatonin from your bloodstream. Normally (that is, without taking supplemental melatonin), the amount of melatonin in your bloodstream falls off around five or six in the morning. This decline in melatonin causes your temperature to rise, which your body interprets as a wake-up signal. When you take a supplemental melatonin at bedtime, you create an artificially sharp rise in your melatonin levels for the next few hours and a correspondingly abrupt decline thereafter, causing your body temperature to rise prematurely–which can interrupt your sleep.

    People have found various remedies for this problem. Some people take a relatively high dose of melatonin at bedtime, which sustains an elevated level of melatonin throughout the night. (Be wary of taking too much melatonin, however, because you may experience next-day drowsiness.) Others take a second, smaller dose of melatonin if and when they wake up in the middle of the night. A third and increasingly common solution is to take melatonin in a timed-release format. Timed-release preparations release the melatonin gradually throughout the night, preventing a sharp decline in the early morning. A number of timed-release preparations are now on the market.

Question: Will taking melatonin interfere with my body's natural production of the hormone?

Answer: Taking hormonal supplements can cause your body to slow down production of those same hormones, a phenomenon known as a "negative feedback reaction." It is not known for certain whether the prolonged use of melatonin causes such a reaction, but preliminary results from an ongoing clinical trial suggest that it many not.

Question: I have heard that melatonin should not be taken by those with an autoimmune disease. I have arthritis. Will I make matters worse by taking medication?

Answer: Melatonin has a complex and not fully understood influence on the immune system. It is theoretically possible that taking the hormone might exacerbate an autoimmune disease by stimulating parts of the immune system that are already too reactive.

Question: I'm taking a number of medications. Will melatonin interfere with the positive effects of those drugs or perhaps cause a negative reaction?

Answer: It is possible that melatonin will interfere with some of the actions of steroid drugs. One reason steroid drugs are prescribed is to suppress the immune system, which is a desirable response when treating a number of conditions such as inflammation and various autoimmune disorders. Melatonin has a stimulatory effect on the immune system.

    There is no evidence that melatonin will counteract the effect of other drugs, however. In fact, melatonin may have a positive effect when taken in conjunction with some medications, in particular those drugs that interfere with the body's natural production of melatonin, such as certain pain relievers, heart medications, and sleeping pills.

    Before you add melatonin to other prescription drugs, consult your doctor.

Question: How do I know if the medication I've purchased is pure and safe?

Answer: Melatonin, like many other substances available in health food stores, is categorized as a food supplement, and producers of food supplements do not have to adhere to the stringent standards mandated for prescription drugs. Therefore, there is less guarantee as to its purity.

    As with other food supplements, it is wise to buy melatonin from a company that has earned a reputation for producing quality products–even if the price is somewhat higher. There are several grades of melatonin available for sale. The purer the product, the higher the cost to wholesalers. Melatonin that sells for a bargain basement price may be made from a lesser-grade raw material.

Source: Reiter, R.J., Robinson, J. Melatonin. Bantam Book, New, 1995.