When is a Drug Not a Drug? the L-Tryptophan Tragedy: Lessons to Be Learned

Abstract

In November, 1989, the Centers for Disease Control (CDC) began receiving reports of a rare condition called Eosinophilia-Myalgia Syndrome (EMS) in individuals known to be taking the amino acid L-tryptophan (LT). The association between LT and EMS came as a surprise to physicians and scientists because LT is an essential amino acid present in the diet and has been available as a nutritional supplement, without a prescription, since the 1960s. However, despite a recall of LT products instituted by the Food and Drug Administration (FDA), as of July 5, 1991, 1,543 cases of EMS, including 31 deaths, have been reported to the CDC. This paper discusses the manufacturing, scientific, and regulatory issues which led to the EMS epidemic and recommends that regardless of how a substance is regulated, its purity be monitored and ensured by a responsible scientific or regulatory agency in order to protect the health of the public.