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Research use only
· 7 min read
Redox biochemistry runs on a currency that most lab catalogues treat as routine. Glutathione (GSH) - the tripeptide L-gamma-glutamyl-L-cysteinylglycine, PubChem CID 124886, CAS 70-18-8, C10H17N3O6S, 307.33 g/mol - is the cell's principal low-molecular-weight thiol and the substrate against which half the enzyme literature in oxidative stress measures itself. Kovalabs supplies the reduced form strictly as a laboratory research reagent for in-vitro and analytical use; everything below describes what published studies have investigated, not any human use.
| Compound | Glutathione (GSH), reduced form |
|---|---|
| Synonyms | L-glutathione reduced; gamma-L-glutamyl-L-cysteinylglycine; GSH |
| Class / mechanism | Tripeptide thiol; principal intracellular low-molecular-weight antioxidant and enzyme cofactor (GSH/GSSG redox couple) |
| Molecular formula | C10H17N3O6S |
| Molecular weight | 307.33 g/mol |
| CAS number | 70-18-8 |
| PubChem CID | 124886 |
Glutathione is a tripeptide, but not a conventionally assembled one. The glutamate residue donates its gamma-carboxyl group - not the alpha-carboxyl - to form the peptide bond with cysteine. That single structural choice makes all the difference at the bench: most cellular peptidases cleave alpha-carboxyl linkages, so GSH survives intracellularly at millimolar concentrations without constant replacement, which is precisely what makes it useful as a redox buffer. The second defining feature is the free cysteinyl thiol (-SH), the chemically reactive centre of the molecule and the atom that does the actual chemistry.
The reduced form is indexed in PubChem under CID 124886, with molecular formula C10H17N3O6S and a molecular weight of 307.33 g/mol; the CAS number is 70-18-8 and the EINECS number 200-725-4. These identifiers cross-resolve cleanly: the PubChem property record for CID 124886 returns InChIKey RWSXRVCMGQZWBV-WDSKDSINSA-N and the IUPAC name (2S)-2-amino-5-[[(2R)-1-(carboxymethylamino)-1-oxo-3-sulfanylpropan-2-yl]amino]-5-oxopentanoic acid, confirming the stereochemistry of the L-tripeptide. Worth stating plainly: the oxidised dimer (glutathione disulfide, GSSG) and the various salt forms carry distinct CIDs and CAS numbers. A vial labelled "glutathione" could be the reduced form, the oxidised form, or a sodium salt - they are not interchangeable, and only the reduced form (CID 124886, CAS 70-18-8) is what this page describes.
| Property | Value | Source |
|---|---|---|
| Compound | L-glutathione, reduced (GSH) | PubChem CID 124886 |
| Chemical class | Tripeptide thiol (gamma-glutamyl peptide) | PubChem / Aquilano 2014 |
| Molecular formula | C10H17N3O6S | PubChem CID 124886 |
| Molecular weight | 307.33 g/mol | PubChem CID 124886 |
| CAS number | 70-18-8 | PubChem CID 124886 |
| EINECS | 200-725-4 | PubChem CID 124886 |
| InChIKey | RWSXRVCMGQZWBV-WDSKDSINSA-N | PubChem CID 124886 |
| Reactive centre | Free cysteinyl thiol (-SH) | Aquilano 2014 |
| Oxidised counterpart | Glutathione disulfide (GSSG, distinct CID) | Aquilano 2014 |
Glutathione's biochemistry turns on a reversible two-electron redox reaction. The cysteinyl thiol of one GSH molecule donates a reducing equivalent; two oxidised glutathiones are joined by a disulfide bond to form GSSG. Glutathione reductase, using NADPH as cofactor, reverses the reaction and regenerates the reduced monomer. The intracellular GSH:GSSG ratio is a widely used analytical index of cellular redox state - it recurs as a measured readout across the laboratory literature for exactly this reason (Aquilano et al., Frontiers in Pharmacology, 2014). This is a description of the molecule's intrinsic redox chemistry; no physiological effect is asserted.
GSH is the thiol substrate and cofactor for two enzyme families central to the oxidative-stress literature. As the cofactor for glutathione peroxidases (GPx), it reduces hydroperoxides with concomitant formation of GSSG. As the conjugating thiol for glutathione S-transferases (GST), it forms thioether conjugates with electrophilic substrates, a reaction studied extensively in xenobiotic detoxification research. The GSSG generated in both reactions feeds back into glutathione reductase, completing the glutathione redox cycle. Biosynthetically, GSH is assembled de novo intracellularly in two sequential ATP-dependent ligation steps: glutamate-cysteine ligase (GCL) forms gamma-glutamylcysteine, then glutathione synthetase adds glycine. These are descriptions of in-vitro enzyme-cofactor relationships and biosynthetic pathway context; no in-vivo outcome is implied (Aquilano et al., 2014).
The entries below are described strictly as study design and the names of the analytes each trial registered. No result, direction, magnitude, effect or benefit is stated or implied; doses quoted are design parameters of the cited trials, not guidance of any kind.
These studies are listed as research context only; they are not findings a reader should expect.
For laboratory work, the dominant handling consideration is oxidative sensitivity. The cysteinyl thiol oxidises readily to the disulfide dimer GSSG - especially in neutral-to-alkaline aqueous solution, in the presence of trace copper or iron, and on exposure to atmospheric oxygen. A sample allowed to oxidise before analysis is no longer measuring reduced glutathione; it is measuring a mixture of GSH and GSSG, which is a different experiment. Store the solid sealed, cool and dry, protected from light and moisture, and away from oxidising agents; exclude or chelate metal contamination.
As a bench procedure, dissolve in oxygen-purged or freshly prepared near-neutral-to-slightly-acidic buffer immediately before analytical use and limit air exposure. Analytical samples are typically acid-stabilised or derivatised promptly to preserve the reduced-form measurement. None of this constitutes a preparation method for any use in humans or animals; it is bench handling of a reagent. See the reconstitution guide for general laboratory handling.
The identity trap here is worth naming explicitly. A vial labelled "glutathione" could be the reduced form (CID 124886, CAS 70-18-8), the oxidised dimer GSSG, a sodium salt, or something else entirely - they carry distinct identifiers and distinct redox and stability profiles. A certificate of analysis is not optional: every Kovalabs batch ships with one, so the mass and purity of the material in hand can be checked against the documented identifiers (formula C10H17N3O6S, MW 307.33 g/mol, CAS 70-18-8) rather than taken on trust. Glutathione sits within the cellular research pathway in the Kovalabs catalogue.
Three tiers, read sceptically. Tier one is solid: the chemistry is not in question - reduced glutathione is a real, well-characterised tripeptide (CID 124886, CAS 70-18-8, C10H17N3O6S) whose gamma-glutamyl bond, free cysteinyl thiol and reversible GSH/GSSG redox couple are documented identity, and it is genuinely present inside cells at millimolar concentrations. Tier two is the middle ground: the enzyme-cofactor roles for GPx and GST, and the redox-cycle chemistry, rest largely on in-vitro and biosynthetic-pathway work - and a cell in a dish is not a person. Tier three is the weakest: the registered human trials catalogued above recorded only analyte concentrations and redox-ratio endpoints, with no outcome this page asserts. It is not a licensed medicine, and it has not been shown to produce defined outcomes in humans. Curiosity is warranted; certainty is not.
Glutathione is supplied by Kovalabs for laboratory and in-vitro research only. It is not a medicine, not a supplement, and not for human or veterinary use, and nothing on this page describes a dose, a route, a schedule or an outcome to pursue. It has not been evaluated by the MHRA or any comparable regulator for safety or efficacy in humans or animals. Every batch is third-party tested with a certificate of analysis. See the full research disclaimer for terms.
Glutathione is the tripeptide L-gamma-glutamyl-L-cysteinylglycine, the principal low-molecular-weight thiol inside cells. Its defining features are a gamma-glutamyl peptide bond that resists most peptidases and a free cysteinyl thiol that is its reactive centre. Kovalabs supplies the reduced form (PubChem CID 124886) strictly as a research reagent, not for human or veterinary use.
The reduced form is indexed in PubChem under CID 124886 with molecular formula C10H17N3O6S and a molecular weight of 307.33 g/mol. The CAS number is 70-18-8 and the EINECS number 200-725-4. The CID, CAS, formula and weight all cross-resolve to the same molecule, reduced L-glutathione, with InChIKey RWSXRVCMGQZWBV-WDSKDSINSA-N.
GSH is reduced monomeric glutathione, carrying a free cysteinyl thiol. GSSG is the oxidised disulfide dimer, formed when two glutathione molecules are joined by a disulfide bond. The two interconvert through a reversible two-electron redox couple, and the GSH:GSSG ratio is a standard analytical index of cellular redox state. GSSG and glutathione salt forms carry distinct identifiers and should not be conflated with the reduced-form reference material.
Reported strictly as study design and endpoint names: a 6-month randomised, double-blind, placebo-controlled trial (Richie et al., 2015; 250 and 1000 mg/day arms) measured glutathione concentrations in blood, erythrocytes, plasma, lymphocytes and buccal cells plus the whole-blood GSSG/GSH ratio. A 4-week randomised, double-blind, placebo-controlled trial (Allen and Bradley, 2011; 500 mg twice daily) measured urinary F2-isoprostanes and 8-OHdG plus erythrocyte glutathione and the GSH:GSSG ratio. These are the analytes the trials measured; no effect of glutathione on them is asserted, and the doses are study-design parameters, not guidance.
As bench handling of a research reagent only. The reduced form is an air-sensitive crystalline solid that oxidises to GSSG in neutral-to-alkaline solution and with trace copper or iron. Store it sealed, cool, dry and protected from light, away from oxidising agents and metal contamination. Reconstitute in oxygen-purged or freshly prepared near-neutral-to-slightly-acidic buffer immediately before analytical use and limit air exposure. Samples are typically acid-stabilised or derivatised promptly to preserve the reduced-form measurement. None of this is a preparation method for any use in humans or animals; see the reconstitution guide.
Glutathione is supplied by Kovalabs strictly as a laboratory research reagent for in-vitro and analytical use. It is not a medicine, not a supplement, and not for human or veterinary use, and it has not been evaluated by the MHRA or any comparable regulator for safety or efficacy in humans or animals. Every batch ships with a certificate of analysis. See the full research disclaimer for terms.