Kynurenic acid is a product of the normal metabolism of amino acid L-tryptophan which has been shown to have a neuroactive profile. It exhibits activity against NMDA receptors and Neuronal acetylcholine receptor subunit alpha-7. It has been investigated as a potential therapeutic compound and as a biomarker in a number of neurological disorders. Although Kenyruic acid exhibits a poor penetration of the blood-brain barrier, it remains to be of particular interest to those researching Schizophrenia.