hi tracy. here the site i got it from. www.biochemicals.com theres info on the site. there is l trytophan in the uk. but this is the onlyone i can find thats fda registered..

back in 1991 in japan i believe. it was banned. because of an japanese outbreak.a type of rare blood disease.a contamination of l trytophan,was believed..
its only been back on the market for the last couple of years..
the one from this site. has been thoughly tested..
it really relaxes me. and makes me sleep better..