Other Name(s):

a-amino-b-[3-indollyl]-propionic acid

Unsubstantiated Claims:

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Tryptophan may induce sleep and has been used to treat insomnia. It is claimed to be a natural antidepressant and stress reducer. It may help treat hyperactivity in children and mania in a person who is manic-depressive. Tryptophan also decreases the appetite.

Recommended Intake:

The FDA has prohibited sales of tryptophan, because it is seen as a dangerous chemical. Although controversy continues as to whether tryptophan is the cause for a potentially fatal side effect, at this time it is recommended that no one take supplemental tryptophan.

Side Effects, Toxicity and Interactions:

The use of tryptophan has been associated with a potentially fatal condition called eosinophilic myositis or eosinophilia-myalgia (EMS). This condition was linked to tryptophan produced by a Japanese company that had recently changed its chemical processes. The cause of the condition has been hotly debated; most scientists doubt that tryptophan itself caused the condition, but rather that it was caused by some intermediate in the reaction.

Ongoing studies have implicated 4,5-tryptophan-dione as the probable contaminant. In a study of over-the-counter tryptophan, this contaminant was found to make up 0.5 to 10.3 percent of the samples of tryptophan. The presence of this contaminant in all samples suggests that current tryptophan supplements are not safe to use.

Additional Information:

Click here for a list of reputable Web sites with general information on nutrition.


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