What Is Glutathione?

Glutathione (GSH) is a tripeptide consisting of three amino acids: glutamate, cysteine, and glycine, linked by the unusual gamma-peptide bond between glutamate and cysteine (giving it the full name gamma-glutamylcysteinylglycine). It is the most abundant intracellular antioxidant in mammalian cells, with cytosolic concentrations typically in the millimolar range. Glutathione exists in two primary forms: reduced glutathione (GSH) and oxidised glutathione disulphide (GSSG), and the GSH/GSSG ratio is a widely used marker of cellular redox status in research settings. TrueCanPeptides provides Glutathione 1500mg for laboratory and research applications.

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Mechanism of Action

Glutathione serves multiple functions in cellular redox biology. As a direct antioxidant, GSH donates electrons to neutralise reactive oxygen species (ROS) and reactive nitrogen species (RNS), becoming oxidised to GSSG in the process. Glutathione reductase then recycles GSSG back to GSH using NADPH, maintaining the reductive capacity of the cell.

Glutathione is also the obligate cofactor for glutathione peroxidases (GPx enzymes), which catalyse the reduction of hydrogen peroxide and lipid hydroperoxides. Additionally, GSH participates in Phase II detoxification through glutathione S-transferases (GST), which conjugate GSH to electrophilic compounds to facilitate their elimination. The tripeptide also regulates protein function via S-glutathionylation — a reversible post-translational modification studied in redox signalling research.

Research Applications

Glutathione is one of the most extensively studied molecules in cell biology research:

• Cellular redox biology: Used as a reference compound and experimental tool for studying oxidative stress, GSH/GSSG ratios, and antioxidant pathway capacity in cell culture models.
• Oxidative stress research: Investigated in models of ROS-induced cell stress to characterise the role of glutathione depletion or supplementation on cell viability and signalling.
• Glutathione peroxidase studies: Employed in enzyme kinetics and activity assays characterising GPx family members and their substrates.
• Detoxification pathway research: Studied in liver cell models for its role in Phase II drug metabolism and xenobiotic conjugation via glutathione S-transferases.
• Mitochondrial redox: Investigated for its role in mitochondrial matrix antioxidant defence, with separate mitochondrial GSH pools studied in the context of organelle-level redox homeostasis.
• Ageing biology: GSH levels and redox status are examined in models of cellular senescence and age-associated oxidative burden.

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Storage & Handling

Glutathione in reduced form (GSH) is susceptible to oxidation. Store the lyophilised or powder form at −20°C under inert atmosphere or in a sealed, desiccated container. Prepare aqueous solutions fresh and use promptly; oxidation in solution is accelerated by light, heat, and heavy metal contamination. For extended storage of dissolved GSH, consider acidic buffers (pH 3–5) or inert gas blanketing. Monitor GSH/GSSG ratio in working preparations when redox state is experimentally critical.

See the Peptide Storage Guide and quality and purity standards.

Related Research

Researchers working in antioxidant and redox biology may also find these compound guides relevant:

• SS-31 (Elamipretide) — mitochondria-targeting peptide studied in cardiolipin and oxidative stress research
• ARA-290 — anti-inflammatory peptide investigated in neuroprotection and cellular stress research
• KPV — anti-inflammatory tripeptide studied in melanocortin receptor and inflammatory signalling research

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Disclaimer: This content is intended for educational and research purposes only. The compounds discussed on this page are not approved for human therapeutic use by Health Canada or any other regulatory authority. They are not intended to diagnose, treat, cure, or prevent any disease or medical condition. TrueCanPeptides supplies research compounds strictly for in vitro and laboratory research use. All information presented is derived from published preclinical and early-phase research literature and does not constitute medical advice. Consult a qualified healthcare professional before making any health-related decisions.

Glutathione: The Master Antioxidant Tripeptide

Glutathione (GSH) is a tripeptide — γ-L-glutamyl-L-cysteinyl-glycine — and the most abundant intracellular antioxidant in mammalian cells, reaching concentrations of 1–10 mM in most cell types. Unlike most peptides, glutathione has an unusual γ-peptide bond between the glutamate and cysteine residues (via glutamate’s side-chain carboxyl rather than its α-carboxyl), which confers resistance to most peptidases and contributes to its intracellular stability.

Structure and Chemistry

• Full name: γ-L-glutamyl-L-cysteinyl-glycine (GSH)
• Amino acids: 3 (with γ-peptide bond — not a standard peptide bond)
• Molecular weight: ~307 Da (reduced form)
• Active group: Free thiol (–SH) on cysteine residue — the site of antioxidant activity
• Oxidized form: GSSG (glutathione disulfide) — two GSH molecules linked by disulfide bond after oxidation
• GSH:GSSG ratio: A key indicator of cellular redox status; normal cells maintain >100:1 ratio
• Format: Lyophilized powder (reduced form)

Biological Functions in Research Context

• ROS scavenging: GSH donates electrons to neutralize reactive oxygen species including hydrogen peroxide (via glutathione peroxidase/GPx), superoxide, and organic peroxides
• Xenobiotic conjugation: Glutathione S-transferases (GSTs) conjugate GSH to electrophilic compounds and drug metabolites, facilitating their export and detoxification — central to drug metabolism research
• Protein thiol protection: GSH protects cysteine residues in proteins from irreversible oxidation via glutathionylation (reversible mixed disulfide formation)
• Redox signalling: The GSH/GSSG ratio regulates redox-sensitive transcription factors (NF-κB, AP-1, Nrf2) and is a key parameter in oxidative stress research models
• Immune cell function: Lymphocytes and macrophages require high intracellular GSH for proliferation and cytokine production; GSH depletion is used to study immunosuppression mechanisms

Storage and Handling

• Store lyophilized at −20°C, desiccated and protected from oxygen exposure
• The free thiol group is highly susceptible to oxidation — minimize air exposure at all stages
• Reconstitute in deoxygenated or nitrogen-purged sterile water for maximum stability
• Post-reconstitution: use immediately or aliquot under inert gas and store at −80°C; oxidizes within hours at room temperature in open air
• Measure GSH:GSSG ratio post-reconstitution if redox state is critical for your assay

Glutathione is supplied for qualified in vitro laboratory research purposes only. Not for human or animal administration. Not evaluated or approved by Health Canada.

Available: Glutathione 1500mg from TrueCanPeptides | NAD+ 1000mg | Immune & Longevity research compounds