Glutathione (GSH) is a tripeptide composed of glutamate, cysteine, and glycine, and is the most abundant intracellular antioxidant in the human body. It serves as a primary substrate for glutathione peroxidase, a key enzyme in neutralizing reactive oxygen species and protecting cells from oxidative damage. Beyond antioxidant function, glutathione plays essential roles in xenobiotic detoxification via conjugation reactions in the liver, immune cell proliferation, and regulation of apoptosis. Research interest also encompasses its role in skin depigmentation, where high-dose glutathione administration has been studied for effects on melanin synthesis pathways.