In 1989 more than 1500 people who took the dietary supplement L-tryptophan for insomnia and
depression developed eosinophilia myalgia syndrome (EMS)-a potentially fatal disease
characterized by an excess of a type of white blood cell called eosinophils. Disease
symptoms include fever, muscle aches and inflammation, and skin rashes. As many as 40 of
the patients who became ill died. It is suspected that impurities in the supplements caused
the disease. More recently, similar impurities have been detected in batches of a similar
dietary supplement called L-5-hydroxytryptophan.
This study is designed to learn more about EMS that develops in patients taking
L-5-hydroxytryptophan. The study is open to patients newly diagnosed with eosinophilia
myalgia who have taken L-5-HTP. Patients in the study will have a physical examination and
urine and blood tests. They may also have X rays, an electrocardiogram, magnetic resonance
imaging (MRI), and a skin test for tuberculosis. They will have a psychiatric interview,
take a memory test, and fill out questionnaires relating to sadness and depression.
Patients may also undergo special tests to study conduction of nerve impulses and muscle
Samples of patients' supplements will be taken for chemical analysis.
The L-tryptophan-related eosinophilia myalgia syndrome (EMS), characterized by eosinophilia,
myalgias, myositis, scleroderma-like skin fibrosis and fasciitis, occurred in 1989 in over
1500 patients who had ingested L-tryptophan for sleep disturbances and depression. The
identical clinical syndrome has also occurred in subjects ingesting L-5-hydroxytryptophan
Recently, a letter to Nature Medicine reported the presence of an impurity in 6 out of 6
samples of L-5-HTP obtained randomly at health food stores. This impurity appears to be the
same as the one identified in material ingested by a family (mother and 2 babies) who had
developed an EMS-like syndrome after ingesting L-5-HTP.
Although there have been no definite new cases of L-5-HTP-related EMS, the FDA is currently
investigating unconfirmed reports of possible new cases.
Patients must be at least 18 years of age.
Patients newly diagnosed with eosinophilia and myalgia, and who ingested L-5-HTP.
Subjects will be defined as having 5-L-HTP related EMS according to the diagnostic
criteria originally established by the CDC for diagnosis of L-tyrptophan-related EMS.