Overview
Glutathione (GSH) is a tripeptide consisting of glutamic acid, cysteine, and glycine, connected by an unusual gamma-peptide bond between the glutamate and cysteine residues. It is the most abundant intracellular antioxidant in mammalian cells, with concentrations ranging from 1–10 mM in the cytoplasm, and is often referred to as the "master antioxidant" due to its central role in cellular redox homeostasis. Unlike most antioxidants, glutathione is synthesized endogenously by virtually all cell types and can be regenerated from its oxidized form (GSSG) by glutathione reductase using NADPH as a cofactor. This regeneration capacity makes glutathione a renewable, catalytic antioxidant system rather than a consumable one — a key distinction in understanding its biological significance.
Mechanism of Action
Glutathione exerts its antioxidant effects through multiple mechanisms. In its primary antioxidant role, GSH donates electrons to neutralize reactive oxygen species (ROS) and reactive nitrogen species (RNS), becoming oxidized to glutathione disulfide (GSSG). GSSG is then reduced back to GSH by glutathione reductase using NADPH, completing the catalytic cycle. As a cofactor for glutathione peroxidases (GPx), GSH facilitates the reduction of hydrogen peroxide (H₂O₂) and organic hydroperoxides to water and alcohols, respectively — a critical defense against lipid peroxidation and oxidative DNA damage. As a substrate for glutathione S-transferases (GSTs), GSH is conjugated to electrophilic xeno
Research Evidence
- Most abundant intracellular antioxidant (1–10 mM cytoplasmic concentration) — the 'master antioxidant'
- Catalytic antioxidant system: regenerated from GSSG by glutathione reductase/NADPH
- GSH/GSSG ratio is a primary indicator of cellular redox state and oxidative stress
- Cofactor for glutathione peroxidases (GPx) — critical defense against lipid peroxidation and oxidative DNA damage
- Substrate for glutathione S-transferases (GSTs) — primary phase II detoxification enzyme system
Bottom line: Glutathione is the most abundant antioxidant in the human body and one of the most important molecules in cellular health. Its role in detoxification, immune function, and oxidative stress management makes it a cornerstone of longevity and disease research. The research-grade lyophilized form supplied by Purgo Labs is for laboratory use only.
Research Protocols & Dosage
Evidence-based research protocols, administration routes, and dosage considerations for Glutathione are detailed in the full compound profile. See also: Dosage guide for Glutathione.
Sourcing & Quality
Glutathione is available from Purgo Labs with third-party COA verification and research-grade purity standards. View Glutathione at Purgo Labs.