The article discusses the importance of glutathione (GSH) in human health and disease. GSH, a water-soluble tripeptide, is the most abundant non-protein thiol in animal cells and plays a crucial role in maintaining cellular redox balance. It serves as an antioxidant, detoxifying electrophilic compounds and peroxides through reactions catalyzed by glutathione S-transferases (GSTs) and glutathione peroxidases (GPx). The redox cycle involving GSH and its oxidized form, glutathione disulfide (GSSG), is tightly regulated to maintain optimal cellular function. Imbalances in GSH levels are associated with various diseases, including cancer, neurodegenerative disorders, cystic fibrosis (CF), HIV, and aging. Polymorphisms in genes encoding GSH-related enzymes, such as γ-glutamylcysteine synthetase (γ-GCS) and GSTs, can influence disease susceptibility and progression. The article also explores the role of GSH in cellular signaling pathways, immune function, and the regulation of protein function through glutathionylation. Additionally, it highlights the therapeutic potential of restoring GSH levels in conditions such as HIV and aging.The article discusses the importance of glutathione (GSH) in human health and disease. GSH, a water-soluble tripeptide, is the most abundant non-protein thiol in animal cells and plays a crucial role in maintaining cellular redox balance. It serves as an antioxidant, detoxifying electrophilic compounds and peroxides through reactions catalyzed by glutathione S-transferases (GSTs) and glutathione peroxidases (GPx). The redox cycle involving GSH and its oxidized form, glutathione disulfide (GSSG), is tightly regulated to maintain optimal cellular function. Imbalances in GSH levels are associated with various diseases, including cancer, neurodegenerative disorders, cystic fibrosis (CF), HIV, and aging. Polymorphisms in genes encoding GSH-related enzymes, such as γ-glutamylcysteine synthetase (γ-GCS) and GSTs, can influence disease susceptibility and progression. The article also explores the role of GSH in cellular signaling pathways, immune function, and the regulation of protein function through glutathionylation. Additionally, it highlights the therapeutic potential of restoring GSH levels in conditions such as HIV and aging.