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Veterinarian Reviewed on June 6, 2012 by Paulina Nelega, RH
Posted in Uncategorized


L-Tryptophan is an amino acid that is produced by animals and plants. L-tryptophan is known as an essential amino acid. This classification means that the body cannot produce it and it must be acquired by food intake. It has been used as an aid to treat insomnia, depression, anxiety, PMDD, and ADD. It has also been used as an assist to smoking cessation, although not all of these uses have been approved by the FDA. It should not be used as a substitute for prescribed medications. It has also been implied that it helps with athletic endeavors and for Tourette’s syndrome.

Function of L-Tryptophan

L-Tryptophan eventually converts to serotonin. Serotonin levels will affect a person’s moods due to the effect on the nerve cells in their brain. It will cause blood vessels to narrow as well.


It is dangerous for anyone to purchase this dietary supplement from foreign sources. Internet vendors are not always reliable and there have been problems with l-tryptophan purchased from sources in foreign countrie. The distribution outside the US is not done under the same standards as those of the FDA. There have been instances when serious medical conditions appeared after the ingestion of l-tryptophan. Back in 1989, a condition called EMS (eosinophylia-myalgia syndrome) surfaced in many people. Many became gravely ill and others died. When the compound was examined, it was found to have trace levels of other ingredients that were impure. For that reason the Food and Drug Administration has limited the availability from unprofessional manufacturers. Unfortunately, the FDA does not have any control over internet sales from foreign vendors.

There haven’t been any reported cases of this syndrome in more recent years, but it will prove beneficial to be aware of the symptoms associated with it. There will be severe muscle pain, primarily in the back, shoulders and legs. This may be accompanied by numbness, tingling, weakness and burning. There can also be tremors, twitching and swelling in your body. In some cases there may also be changes in the skin such as yellowing, hardening and dryness. You may experience an uneven heartbeat and difficulty breathing.

Before taking L-Tryptophan

It is vitally important to have a conference with your physician, pharmacist, herbalist or your other healthcare providers before using l-tryptophan. There are conditions that will prohibit the use of this supplement. It may be necessary to adjust the dosage and have special tests performed before you begin taking it. Some indications for caution are:

• Kidney disease

• Liver disease

• Fibromyalgia or other muscle disorder

• High levels of eosinophils, a form of white blood cells

Studies have not been conducted aimed to the safety of taking l-tryptophan if you are pregnant or plan to become pregnant. There is a possibility that it will pass into the breast milk and can cause harm to a nursing infant. Do not give any food supplement to a child without first consulting with your physician.

Sources of L-Tryptophan

Most of the protein based foods that we eat have tryptophan. This is especially true in oats, chocolate, dates, milk, cottage cheese, yogurt, red meat, fish, poultry, eggs, sunflower seeds, peanuts and chickpeas. The amount of tryptophan in turkey is no higher than in other meats. It is believed that the fatigue following that Thanksgiving or Christmas meal may be due to the carbohydrates that are eaten at that same meal.

Read also: Hawthorn Berry and Restless Leg Syndrome

Our Expert

Paulina Nelega, RH
Paulina Nelega, RH, has been in private practice as a Clinical Herbalist for over 15 years. She has developed and taught courses in herbal medicine, and her articles on health have appeared in numerous publications. She is very passionate about the healing power of nature. Ask Dr. Jan

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