The FDA temporarily banned Tryptophan supplements in 1989 due to a contaminated batch of product manufactured by a single Japanese company (Showa Denko) using a recombinant genetically engineered method instead of the common and easy fermentation method.

The contamination led to an EMS outbreak affecting only those customers who bought from suppliers using the faulty raw material. The FDA lifted the ban in 2006 after research showed the cause was not Tryptophan but impurities in the specific batch.

Prior to the ban Tryptophan was a very popular supplement in the 1970s and 1980s, and continued to be used in animal feed as a necessity for the health and growth of farmed animals

At Turkey Sleep we are fully aware of the dangers of contaminated or faulty ingredient supply and therefore we only source from 100% VERIFIED and NON-GMO suppliers using the 100 year old fermentation process that results in pure ultra high quality L-Tryptophan amino acid.