Sunset:
As I promised, here is the information I was able to find on L-Theanine. On-going research is being conducted on L-Theanine and anxiety, but more information is needed before solid conclusions can be drawn.
<A HREF="
http://www.pdrhealth.com/drug_info/nmdr ... 0296.shtml" TARGET=_blank>
http://www.pdrhealth.com/drug_info/nmdr ... 6.shtml</A>
Also, I forgot to post the following information on L-Tryptophan. Thought you might find it of interest. It is from the FDA (it covers amino acid supplements in general and then L-Tryptophan). You will see that it is consistent with what the other link said.
"Amino acids are the individual constituent parts of proteins. Consumption of foods containing intact proteins ordinarily provides sufficient amounts of the nine amino acids needed for growth and development in children and for maintenance of health of adults. The safety of amino acids in this form is generally not a concern. When marketed as dietary supplements, amino acids are sold as single compounds, in combinations of two or more amino acids, as components of protein powders, as chelated single compounds, or in chelated mixtures. Amino acids are promoted for a variety of uses, including body-building. Some are promoted for claimed pharmacologic effects.
The Federation of American Societies for Experimental Biology (FASEB) recently conducted an exhaustive search of available data on amino acids and concluded that there was insufficient information to establish a safe intake level for any amino acids in dietary supplements, and that their safety should not be assumed. FASEB warned that consuming amino acids in dietary supplement form posed potential risks for several subgroups of the general population, including women of childbearing age (especially if pregnant or nursing), infants, children, adolescents, the elderly, individuals with inherited disorders of amino acid metabolism, and individuals with certain diseases.
At least two of the amino acids consumed in dietary supplements have also been associated with serious injuries in healthy adults.
A. L-tryptophan
L-tryptophan is associated with the most serious recent outbreak of illness and death known to be due to consumption of dietary supplements. In 1989, public health officials realized that an epidemic of eosinophilia-myalgia syndrome (EMS) was associated with the ingestion of L-tryptophan in a dietary supplement. EMS is a systemic connective tissue disease characterized by severe muscle pain, an increase in white blood cells, and certain skin and neuromuscular manifestations.
More than 1,500 cases of L-tryptophan-related EMS have been reported to the national Centers for Disease Control and Prevention. At least 38 patients are known to have died. The true incidence of L-tryptophan-related EMS is thought to be much higher. Some of the individuals suffering from L-tryptophan-related EMS have recovered, while other individuals' illnesses have persisted or worsened over time.
Although initial epidemiologic studies suggested that the illnesses might be due to impurities in an L-tryptophan product from a single Japanese manufacturer, this hypothesis has not been verified, and additional evidence suggests that L-tryptophan itself may cause or contribute to development of EMS. Cases of EMS and related disorders have been found to be associated with ingestion of L-tryptophan from other batches or sources of L-tryptophan. These illnesses have also been associated with the use of L-5-hydroxytryptophan, a compound that is closely related to L-tryptophan, but is not produced using the manufacturing process that created the impurities in the particular Japanese product."
(from: <A HREF="
http://www.cfsan.fda.gov/~dms/ds-ill.html" TARGET=_blank>
http://www.cfsan.fda.gov/~dms/ds-ill.html</A> )
