FDA
TALK PAPER

Food and Drug Administration
U.S. Department of Health and Human Services
Public Health Service 5600 Fishers Lane Rockville, MD 20857
FDA Talk Papers are prepared by the Press Office to guide FDA personnel in responding with consistency and accuracy to questions from the public on subjects of current interest. Talk Papers are subject to change as more information becomes available. 
 
T98-48                        Print Media:         301-827-6242
August 31, 1998               
                              Consumer Inquiries:  800-532-4440

IMPURITIES CONFIRMED IN DIETARY SUPPLEMENT 5-HYDROXY-L-TRYPTOPHAN

FDA scientists have confirmed the presence of impurities in some 5-hydroxy-L-tryptophan (5HTP) products currently marketed and widely promoted as dietary supplements. These products are being used as aids for insomnia, depression, obesity, and in children with attention deficit disorder. FDA's analytical results are consistent with those obtained and published by researchers from the Mayo Clinic.

One of these impurities is known as "peak X." Although the significance of finding "peak X" and other impurities in dietary supplements containing 5-HTP is unknown, past experiences with these products suggests vigilance is warranted. "Peak X" was identified in one case of the illness eosinophilia-myalgia syndrome (EMS) associated with 5HTP in 1991. Impurities similar to "peak X" were also found in L-tryptophan that was associated with a 1989 epidemic of EMS. 5HTP and L-tryptophan are related in that 5HTP is synthesized from L-Tryphophan in the body. The exact cause of the 1989 epidemic and of the case of EMS associated with 5HTP remain unclear.

EMS is a serious systemic illness characterized by elevations of certain white blood cells and severe muscle pain. The Centers for Disease Control and Prevention (CDC) has identified more than 1,500 cases of EMS, including at least 38 deaths associated with the use of L-tryptophan. The medical literature reports approximately 10 previous cases of EMS worldwide associated with use of products containing 5HTP.

Research has not resolved whether these EMS were caused by L-tryptophan or 5HTP, one or more impurities, or other factors. At this time, FDA is unaware of any recent illnesses associated with the 5HTP products being sold as dietary supplements. The widespread promotion and use of these products, however, began only recently.

FDA is working closely with its colleagues at CDC and NIH to monitor the situation and is consulting with other professionals and patient groups. To assist in its monitoring efforts, FDA encourages consumers to contact FDA's MedWatch program by calling 1-800-FDA-1088 to obtain information about how to report serious adverse events.

Physicians and other health care practitioners are encouraged to report such adverse events to FDA's MedWatch program by phone (1-800-FDA-1088), fax (1-800-FDA-0178) or mail (using postage-paid form) to FDA, HF-2, 5600 Fishers Lane, Rockville, MD 20852-9787.

This is a mirror of the page at HTTP://www.fda.gov/bbs/topics/ANSWERS/ANS00891.html

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