Isotonix® L-Tryptophan is an isotonic version of the essential amino acid, l-tryptophan. L-Tryptophan is an essential amino acid that helps maintain healthy levels of serotonin in the brain. Serotonin helps regulate mood. Isotonix® L-Tryptophan provides maximum results by combining itself with niacin and Vitamin B6, members of the B vitamin family, which promote normal...