Mitochondrial glutathione (mGSH) plays a critical role in maintaining cellular redox homeostasis and preventing disease. Mitochondria are essential for energy production through oxidative phosphorylation (OXPHOS), which generates adenosine triphosphate (ATP). However, the electron transport chain (ETC) in mitochondria produces reactive oxygen species (ROS), which can cause oxidative stress and damage cells if not properly regulated. Glutathione (GSH), a major cellular antioxidant, is synthesized in the cytoplasm and transported to mitochondria, where it helps neutralize ROS and maintain mitochondrial function. mGSH is involved in redox regulation, electron transfer, and the biosynthesis of iron-sulfur clusters within mitochondria. A imbalance in the ratio of mitochondrial ROS to mGSH can lead to cell dysfunction, apoptosis, necroptosis, and ferroptosis, contributing to various diseases. ROS are produced during OXPHOS and can cause oxidative damage to proteins, lipids, and DNA. Mitochondrial antioxidant enzymes, such as superoxide dismutase (SOD), help neutralize ROS, but their activity can be affected by factors like mitochondrial dysfunction and oxidative stress. GSH is a key component of the redox system, with its reduced form (GSH) and oxidized form (GSSG) playing critical roles in maintaining cellular redox balance. The GSH/GSSG ratio reflects the cell's redox capacity and is essential for cellular health and function. GSH is synthesized in the cytoplasm and transported to mitochondria via specific carriers. The synthesis of GSH involves enzymatic steps, including the action of GSH synthetase and GCL (glutamate-cysteine ligase). GSH levels decrease with age and are affected by various factors, including oxidative stress, inflammation, and disease. GSH deficiency is associated with a range of diseases, including chronic diseases, microbial infections, and genetic disorders. GSH deficiency can lead to increased oxidative stress, mitochondrial dysfunction, and programmed cell death, such as apoptosis, autophagy, necroptosis, and ferroptosis. Therapeutic strategies to increase GSH levels include supplementation with synthetic GSH, amino acids like cysteine, glycine, and glutamic acid, and N-acetylcysteine (NAC). Maintaining the GSH/GSSG ratio and reducing ROS accumulation are critical for mitochondrial function and antioxidant defense. Adjunctive therapies, such as probiotics, traditional Chinese medicines, and zinc supplementation, can also enhance antioxidant effects and reduce oxidative stress. Further research is needed to develop effective therapies for diseases associated with oxidative stress and mitochondrial dysfunction.Mitochondrial glutathione (mGSH) plays a critical role in maintaining cellular redox homeostasis and preventing disease. Mitochondria are essential for energy production through oxidative phosphorylation (OXPHOS), which generates adenosine triphosphate (ATP). However, the electron transport chain (ETC) in mitochondria produces reactive oxygen species (ROS), which can cause oxidative stress and damage cells if not properly regulated. Glutathione (GSH), a major cellular antioxidant, is synthesized in the cytoplasm and transported to mitochondria, where it helps neutralize ROS and maintain mitochondrial function. mGSH is involved in redox regulation, electron transfer, and the biosynthesis of iron-sulfur clusters within mitochondria. A imbalance in the ratio of mitochondrial ROS to mGSH can lead to cell dysfunction, apoptosis, necroptosis, and ferroptosis, contributing to various diseases. ROS are produced during OXPHOS and can cause oxidative damage to proteins, lipids, and DNA. Mitochondrial antioxidant enzymes, such as superoxide dismutase (SOD), help neutralize ROS, but their activity can be affected by factors like mitochondrial dysfunction and oxidative stress. GSH is a key component of the redox system, with its reduced form (GSH) and oxidized form (GSSG) playing critical roles in maintaining cellular redox balance. The GSH/GSSG ratio reflects the cell's redox capacity and is essential for cellular health and function. GSH is synthesized in the cytoplasm and transported to mitochondria via specific carriers. The synthesis of GSH involves enzymatic steps, including the action of GSH synthetase and GCL (glutamate-cysteine ligase). GSH levels decrease with age and are affected by various factors, including oxidative stress, inflammation, and disease. GSH deficiency is associated with a range of diseases, including chronic diseases, microbial infections, and genetic disorders. GSH deficiency can lead to increased oxidative stress, mitochondrial dysfunction, and programmed cell death, such as apoptosis, autophagy, necroptosis, and ferroptosis. Therapeutic strategies to increase GSH levels include supplementation with synthetic GSH, amino acids like cysteine, glycine, and glutamic acid, and N-acetylcysteine (NAC). Maintaining the GSH/GSSG ratio and reducing ROS accumulation are critical for mitochondrial function and antioxidant defense. Adjunctive therapies, such as probiotics, traditional Chinese medicines, and zinc supplementation, can also enhance antioxidant effects and reduce oxidative stress. Further research is needed to develop effective therapies for diseases associated with oxidative stress and mitochondrial dysfunction.