L-glycine (and sipernet)

Glycine is a simple non-essential amino acid, and is the only amino acid that is not optically active (it has no stereoisomers). Glycine is one of the 20 common amino acids found in proteins – it is obtained naturally from fish, meat, beans and dairy products.

This amino acid is essential for the biosynthesis of nucleic acids as well as of bile acids, porphyrins, creatine phosphate, and other amino acids. Glycine enhances the activity of chemical messengers (neurotransmitters) in the brain that are involved in memory and cognition.