Glutathione is a tripeptide molecule consisting of glutamic acid, cysteine, and glycine. It is present in every cell in the human body and plays an essential role in maintaining the redox balance, regulating detoxification pathways, and protecting against oxidative stress. The metabolism of glutathione is a complex process that involves multiple enzymes and pathways. Understanding the intricate pharmacokinetics of glutathione is crucial for comprehending the pathogenesis of several diseases. The primary pathway of glutathione biosynthesis is through the action of two enzymes, gamma-glutamylcysteine synthetase (GCS) and glutathione synthetase (GS). GCS catalyzes the formation of gamma-glutamylcysteine from glutamic acid and cysteine, which is followed by the addition of glycine by GS to complete the synthesis of glutathione. The regulation of GCS is a key step in glutathione metabolism, and it is influenced by various physiological and pathological factors such as cytokines, oxidative stress, and inflammation. Apart from de novo synthesis, glutathione metabolism also involves the recycling of oxidized glutathione (GSSG) to its reduced form (GSH) through the action of the enzyme glutathione reductase. The ratio of GSH/GSSG is a reliable indicator of the redox state of a cell and is involved in signaling processes in various cellular pathways. Additionally, the conjugation of glutathione to xenobiotic compounds by glutathione S-transferases (GSTs) is a crucial step in the detoxification of many harmful chemicals and drugs. Recent advances in understanding the role of glutathione metabolism in pathological conditions have shed light on its potential therapeutic applications. Several diseases such as cancer, neurodegenerative disorders, and cardiovascular diseases are associated with alterations in glutathione metabolism. For instance, the dysregulation of glutathione metabolism is implicated in the development of drug resistance in cancer cells. Therefore, targeting glutathione metabolism has emerged as a potential therapeutic strategy for cancer treatment. In conclusion, glutathione plays a critical role in the maintenance of cellular redox balance and is involved in various detoxification pathways. The pathways involved in glutathione metabolism are complex and involve several enzymes, which are influenced by various physiological and pathological factors. Understanding the pharmacokinetics of glutathione is of utmost importance for the development of targeted therapeutic interventions for several diseases.