L-Tryptophan is an essential amino acid. Humans cannot synthesize it and must obtain the compound from their nutritional diet. It is used in the biosynthesis of proteins and is a precursor to the important neurotransmitter serotonin. 

L-Tryptophan is converted in your brain to 5-Hydroxytryptophan (5-HTP) which in turn is converted to the neurotransmitter Serotonin, which is then modified to Melatonin. L-Tryptophan, 5-HTP and Melatonin can be purchased today as dietary supplements, but it is important to understand that chemically they are all very similar, containing what is known as an indole ring. All three have been implicated in possible onset of EMS-like symptoms in recent times.


There is little research continuing in the effort to find a cure for Eosinophilia-Myalgia Syndrome. This is due to the fact that the epidemic stopped soon after L-Tryptophan was recalled by the FDA and that the numbers of those infected were relatively small in comparison to victims of other diseases.  Additionally, since the genetically engineered bacterium is no longer available, definitive experiments cannot be done to resolve the problem. There is some information available, however, which may be helpful to you when explaining what you have to physicians and family.

"Under the 1994 DSHEA (Dietary Supplement Health and Education Act),  I can sell hemlock as a supplement.  It's pure.  It's natural.  And as Socrates found out, it just as naturally kills you."

-Victor Herbert, professor of medicine at the Mount Sinai School of Medicine and
 the Bronx VA Medical Center in New York.

Is there a test for EMS?

Unfortunately, there is no conclusive medical test to prove if you have EMS. That is one of the most frustrating aspects of coping with this disease.  For the most part, doctors don't know much about EMS. They often do not believe you when you tell them you have EMS. For newly sick patients, many doctors will not even consider a diagnosis of EMS.

For now, we can only print articles from our medical page to help educate the physicians. These three are recommended:

eMedicine - Eosinophilia-Myalgia Syndrome : Article by Nicole Quartarolo, MD

eMedicine - Eosinophilia-Myalgia Syndrome : Article by Shrilekha Sairam, MD,

Gold Standard - Criteria Used To Determine Cases of EMS


Current EMS Research Articles:


NEMSN Newsletter Interview with Dr. Clawu - 2002

War on the Homefront: The Enemy Within - 2002

FDA Paper on L-tryptophan & 5-hydroxy-L-tryptophan - 2001

Notes On Tryptophan Disaster - Stephen Barrett M.D. - 2001

1999 NEMSN Health Survey - Karen Tonso - 1999

EMS Long Term Complications - Espinoza, MD - 1999

Status of EMS Research - Gleich MD - 1998

EMS - Peter E. Callegari, M.D. - 1998

Pain, Fatigue, Sleep in EMS - Kaufman - 1998

Chronic EMS Auto Immune Study -McKinley,MD -1997

EMS: Selective Cognitive Impairment, Longitudinal Effects,
and Neuroimaging Findings

The Neuroscience & Endocrinology of Fibromyalgia - 1996

Eye Problems with EMS - Tipperman - 1996

Bitter Pill - Dateline Segment - 1995

Truth About Tryptophan - A.S. Gissen - 1993

Mayo Clinic Editorial

Summary of Tryptophan Toxicity Incident -  John Fagan

EMS Description for Physicians

Each person should seek the medical advice of their own medical professional
for their own situation.

The information contained in these articles is of a general nature.

NEMSN Position Statement on Bio-Engineering of L-Tryptophan related to Eosinophilia-Myalgia Syndrome:
"Even though the bacteria used to produce L-Tryptophan was genetically modified, there is insufficient evidence to prove that these modifications were solely responsible for the contaminants linked to the Eosinophilia-Myalgia Syndrome."