Tryptophan-Induced Eosinophilia–Myalgia Syndrome

Abstract

Beginning in the late spring of 1989, large numbers of patients became ill with a disorder first recognized the following October and termed the eosinophilia—myalgia syndrome.1 , 2 Almost all the people affected had taken dietary supplements of tryptophan, a naturally occurring amino acid publicized as useful for the treatment of insomnia, depression, and premenstrual symptoms. The median dose ingested was 1.5 g per day — twice the usual dietary intake. The duration of ingestion varied from a few weeks to several years, and a few patients had stopped taking the tryptophan before their symptoms appeared. As of February 9, 1990, the . . .