Cellular Redox Homeostasis & Detoxification
L-Glutathione Reduced — Master Cellular Antioxidant
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.
Reduced glutathione (GSH) is a tripeptide with the sequence γ-Glu-Cys-Gly. The gamma-peptide bond between glutamate and cysteine (rather than the standard alpha-peptide bond) is a critical structural feature: it protects glutathione from degradation by most intracellular peptidases, which cleave alpha-peptide bonds. This unusual linkage is also why glutathione synthesis requires two dedicated enzymes (glutamate-cysteine ligase and glutathione synthetase) rather than the ribosomal machinery used for standard protein synthesis.
The thiol group (-SH) of the cysteine residue is the functionally active site of glutathione, serving as the electron donor in antioxidant reactions. The molecular weight is 307.32 Daltons.
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 xenobiotics and endogenous metabolites, facilitating their excretion and detoxification.
GSH also maintains the redox state of protein thiol groups through thiol-disulfide exchange reactions, protecting enzymes and structural proteins from oxidative inactivation.
Glutathione is often called the body's 'master antioxidant' — and that's not marketing language, it's biochemistry. It's a tripeptide (three amino acids: glutamate, cysteine, and glycine) that your body produces in every cell, and it's the primary molecule your cells use to neutralize oxidative stress, detoxify harmful compounds, and recycle other antioxidants like vitamins C and E.
Glutathione works through two main mechanisms. First, it directly neutralizes reactive oxygen species (ROS) — the unstable molecules that damage DNA, proteins, and cell membranes. Second, it's the primary substrate for glutathione S-transferase enzymes, which are your liver's main detoxification machinery. It also regenerates oxidized vitamin C back to its active form. Glutathione levels decline with age, chronic illness, and environmental toxin exposure, which is why it's a key biomarker in aging and disease research.
Oxidative stress is implicated in virtually every major chronic disease — cardiovascular disease, neurodegeneration, cancer, and diabetes. Glutathione is the frontline defense against it. Research into glutathione depletion and supplementation is relevant to understanding aging, liver disease, immune function, and the mechanisms of many drug toxicities (acetaminophen overdose, for example, kills liver cells by depleting glutathione).
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.
Donates electrons to neutralize reactive oxygen and nitrogen species, becoming GSSG; regenerated by glutathione reductase/NADPH.
Enables GPx-mediated reduction of H₂O₂ and organic hydroperoxides, protecting against lipid peroxidation and oxidative DNA damage.
Conjugated to electrophilic xenobiotics and endogenous metabolites by glutathione S-transferases, facilitating renal and biliary excretion.
Maintains protein cysteine residues in reduced state via thiol-disulfide exchange, preserving enzyme activity and structural protein integrity.
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| Compound Class | Tripeptide (γ-Glu-Cys-Gly) — not a standard peptide bond |
| Molecular Weight | 307.32 Da |
| Active Site | Cysteine thiol group (-SH) |
| Intracellular Concentration | 1–10 mM (cytoplasm) |
| Redox Forms | GSH (reduced) / GSSG (oxidized) |
| Available Sizes | 200mg vials |
| Form | Lyophilized powder |
| Purity | ≥99% (third-party tested) |
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Purchase Glutathione at Purgo LabsMedical Disclaimer: All content on this site is for educational and research purposes only. Research peptides are not FDA-approved for human use. Always consult a qualified healthcare professional before considering any peptide or supplement protocol. Nothing on this site constitutes medical advice, diagnosis, or treatment.
