Phe-Glu-Cys-Gly is a tetrapeptide comprising L-phenylalanine, L-α-glutamic acid, L-cysteine, and glycine. L-phenylalanine is an essential amino acid important for protein synthesis and the production of neurotransmitters. L-α-glutamic acid plays a role in cellular metabolism and neurotransmission. L-cysteine is a sulfur-containing amino acid involved in antioxidant defense and protein structure. Glycine contributes to collagen formation and various metabolic processes. This peptide combines these amino acids to potentially support metabolic processes, antioxidant defenses, and overall health.