Page data last changed: . Registry refreshes and identity assessments are separate from scientific content review.
The body's most abundant intracellular thiol antioxidant.
Also known as: GSH · gamma-glutamylcysteinylglycine
Part of the Foundational & therapeutic peptides cluster
Overview
Glutathione (GSH) is a tripeptide of glutamate, cysteine and glycine and the most abundant small-molecule antioxidant inside human cells. Its reactive cysteine thiol drives redox and detoxification chemistry. It is widely sold as a supplement and studied in biochemistry; this page is educational and not medical advice.
Source & context
Biological / chemical source: Synthesized in nearly all human cells from glutamate, cysteine and glycine
Primary research or clinical context: Sold as a dietary supplement; studied in biochemistry
An unusual peptide bond
Glutathione is written as γ-Glu-Cys-Gly because glutamate joins cysteine through its side-chain (gamma) carboxyl rather than the usual alpha linkage. This gamma bond resists ordinary peptidases, helping the molecule persist inside cells where its cysteine thiol cycles between reduced (GSH) and oxidized (GSSG) forms.
Role and availability
Glutathione participates in neutralizing reactive oxygen species and conjugating toxins for excretion, making it a central redox buffer. It is available as an over-the-counter supplement, though oral absorption is debated in the literature. This educational summary describes its chemistry without dosing or health-outcome claims.
Sequence of the selected reference form
Sequence backbone for the reference form: Reduced L-glutathione, gamma-L-glutamyl-L-cysteinylglycine. Termini, stereochemistry and modifications are described below.
XCG
X positions gamma-L-glutamyl residue; its gamma-carboxyl, rather than alpha-carboxyl, forms the peptide bond to L-cysteine. X marks a noncanonical residue; see the expanded sequence and reference chemistry below.
Analyze sequences in the playground →Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
The primary PubChem IUPAC name and molecular graph establish gamma-Glu-Cys-Gly order, both L stereocentres and a reduced thiol. This is a non-ribosomal tripeptide, so no UniProt precursor is assigned. X avoids depicting its first bond as an ordinary alpha-peptide linkage.
- Molecular form
- Reduced L-glutathione, gamma-L-glutamyl-L-cysteinylglycine
- Species
- Not species-specific; physiological biosynthetic L-form
- Termini (N / C)
- Free alpha-amino group of L-glutamate / Free glycine carboxylic acid (-COOH); glutamate alpha-carboxyl also remains free
Average reference mass · Molecular identity assessment: 2026-10-05
Reference policy updated: 2026-10-05
gamma-L-Glu-Cys-Gly-OH
- Molecular formula
- C10H17N3O6S
- Average reference mass
- ≈ 307.33
- Backbone
- Reduced L-glutathione, gamma-L-glutamyl-L-cysteinylglycine
- C-terminus
- Free glycine carboxylic acid (-COOH); glutamate alpha-carboxyl also remains free
- PubChem CID: 124886
Chemistry values: curated profile, PubChem.
Clinical development snapshot
ClinicalTrials.gov lists 270 registered studies with “Glutathione” as an intervention (snapshot 2026-10-01). A registry footprint is not evidence of efficacy or approval.
| NCT | Title | Phase | Status | Updated |
|---|---|---|---|---|
| NCT07833865 | The Effect of Light Therapy on Cellular Energy and Oxidative Stress in Healthy Adults and Type 1 Diabetic Pati | Not applicable | not yet recruiting | 2026-09-25 |
| NCT03459287 | Study to Evaluate the Efficacy & Safety of the INTERCEPT Blood System for RBCs in Complex Cardiac Surgery Pati | Phase 3 | completed | 2026-09-22 |
| NCT07304440 | Adia Med of Winter Park LLC Autism Spectrum Disorder Research Study | Phase 1 | recruiting | 2026-09-22 |
| NCT04740580 | Glutathione, Brain Metabolism and Inflammation in Alzheimer's Disease | Early phase 1 | active not recruiting | 2026-09-09 |
| NCT03493178 | Glutathione in Mild Cognitive Impairment | Early phase 1 | active not recruiting | 2026-09-04 |
| NCT07792369 | 26DT052; Scaling Busulfan Dose to Body Surface Area in Children | Phase 1 | not yet recruiting | 2026-08-28 |
Glutathione — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Reduced L-glutathione, gamma-L-glutamyl-L-cysteinylglycineAverage reference mass: 307.33 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
Change log
Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.
- Trials1 registered study added on ClinicalTrials.gov (now 270).
FAQ about Glutathione
What is Glutathione?+
Glutathione (GSH) is a tripeptide of glutamate, cysteine and glycine and the most abundant small-molecule antioxidant inside human cells. Its reactive cysteine thiol drives redox and detoxification chemistry. It is widely sold as a supplement and studied in biochemistry; this page is educational and not medical advice.
What Canadian product status is recorded for Glutathione?+
Canadian product status for Glutathione has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the length of the selected reference form for Glutathione?+
The selected reference form (Reduced L-glutathione, gamma-L-glutamyl-L-cysteinylglycine) has 3 residues or residue-derived units in its backbone. Other forms in this family may have a different length.
Related peptides
References & further reading
- 1.Averill-Bates (2023). The antioxidant glutathione. Vitam Horm
- 2.Sarkar et al. (2025). Glutathione as a skin-lightening agent and in melasma: a systematic review. Int J Dermatol
- 3.Pelton (2024). The Glutathione Theory of Aging. Altern Ther Health Med
- 4.Morris et al. (2013). Glutathione and infection. Biochim Biophys Acta
- 5.Iskusnykh et al. (2022). Glutathione in Brain Disorders and Aging. Molecules
- 6.Oestreicher et al. (2019). Glutathione: subcellular distribution and membrane transport (1). Biochem Cell Biol
- 7.Calabrese et al. (2017). Mitochondrial Glutathione: Regulation and Functions. Antioxid Redox Signal
- 8.Reid et al. (2000). Methods for measuring glutathione concentration and rate of synthesis. Curr Opin Clin Nutr Metab Care
- 9.PubChem — compound summary for Glutathione (CID 124886)
- 10.Wikipedia — Glutathione