Melatonin - What Is It Made Of?

What Is It Made Of?

Melatonin is a hormone found naturally in the human body, in other animals, in certain plants, and even in some foods. It is made from tryptophan (TRIP-tuh-fan), an essential amino acidAn amino acid that is only found in food; amino acids make up proteins.. When tryptophan is ingested, the body turns it into serotonin that is then made into melatonin. The pineal gland is the primary location for melatonin production but the retina and intestines make small amounts as well.

Melatonin supplements are either synthetic (human-made) or natural (contain animal products). They are chemically identical to the melatonin that is produced by the human body. Some people think that using the natural melatonin, typically made from the pineal glands of animals such as sheep, run a greater risk of being contaminated by a virus. Therefore, the synthetic version is the most recommended and most popular form of melatonin. However, since the FDA does not regulate it, one can never be sure of the effectiveness, purity, or safety of the supplement.

The Trouble with L-tryptophan

Tryptophan is an essential amino acid from which melatonin is made in the body. It was once available as a dietary supplement, known as L-tryptophan. Much like melatonin, it was marketed as a sleep aid. However, in 1989, a batch of L-tryptophan pills (all made in Japan) was contaminated and caused 1,500 people to contract the disease eosinophilia-myalgia syndrome (EMS; pronounced ee-oh-sin-oh-FIHlee-uh my-AL-jee-uh). EMS causes weakness, severe muscle and joint pain, headaches, fever, and shortness of breath. More than thirty people died from the disease in the United States. The FDA banned L-tryptophan, and from that point on Americans had to get tryptophan from food sources.

Some foods that contain tryptophan include the following:

  • Almonds
  • Bananas
  • Chicken
  • Cottage Cheese
  • Eggs
  • Ice Cream
  • Milk
  • Peanuts
  • Shrimp
  • Soy Nuts
  • Tofu
  • Tuna
  • Turkey
  • Yogurt

As a supplement, melatonin consists of much higher amounts of the hormone than are naturally secreted at any one time in the body. A single dose is usually 500 micrograms to 5 milligrams per dose, more than 10 times higher than what is normal in the human body.

A scientist wears a protective suit as he makes up a batch of melatonin in a laboratory in the United Kingdom. Bryn Colton/Assignments Photographers/Corbis.
A scientist wears a protective suit as he makes up a batch of melatonin in a laboratory in the United Kingdom. © Bryn Colton/Assignments Photographers/Corbis.

Studies have not shown the high doses cause greater benefit or greater risk to the body. However, a doctor should be consulted before taking any supplement.

Age Factors

Before reaching puberty, children create the largest amounts of melatonin, with the highest levels between the ages of four and seven. At puberty, melatonin production begins to slow down and gradually decreases to an average of about 30 micrograms per day. Some researchers suggest that the decrease in the level of melatonin at puberty may be related to the fact that the child is maturing sexually.

Research findings have been inconsistent about whether or not melatonin continues to diminish with age. A number of scientists believe that melatonin production decreases as the body ages, which might explain why elderly people have greater sleep problems. However, a study by Dr. J. B. Fourtillan, published in the January 2001 issue of American Journal of Physiology, indicated that the levels of melatonin did not differ between a group of 34 healthy adults over age 65 and a group of 101 healthy adults under age 30.