Glutathione
Also known as: GSH, γ-L-glutamyl-L-cysteinylglycine, L-glutathione
Glutathione (also called GSH or γ-L-glutamyl-L-cysteinylglycine) is an endogenous tripeptide antioxidant in the Antioxidant / Redox Modulator class. Glutathione is a tripeptide of glutamate, cysteine and glycine and the principal intracellular thiol buffer, present in millimolar concentrations in most cells.
For research use only.
Key Facts
- CAS
- 70-18-8
- Molecular Weight (MW)
- 307.32 g/mol
- Half-life
- ~1.5 hours (IV); oral bioavailability limited
- FDA status
- Not Approved
- Evidence level
- Limited Human Evidence
- Human dose established
- Yes
- Administration Route
- Oral (the only route with controlled trial dosing)
- Frequency
- Once or twice daily
- Last updated
- Sep 6, 2026
- Reviewed
- Aug 30, 2026
- Targets
- Reactive oxygen speciesGlutathione peroxidase
Vendor price snapshot
Each vendor counts once, at the median price per mg of its own listings; the typical range is the middle half of vendors. From public vendor listings collected between Dec 2025 and Sep 2026, so confirm the live price on the vendor site. Peptide Library does not sell peptides.
- Vendors listing this peptide
- 27
- Listed offers
- 34
- Median price per mg
- $0.048/mg
- Typical $0.043–$0.096/mg
Research summary
Endogenous antioxidant tripeptide sold as an oral supplement and used IV in clinics. Not FDA-approved as a standalone drug for systemic “detox” or skin-lightening claims.
Peptide Library's Glutathione profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Glutathione dosage chart
Glutathione has human dosing evidence, but only by mouth. Randomised trials support oral doses of 250 mg once or twice daily, 500 mg once daily, and 250–1000 mg daily for raising body stores. The intravenous and intramuscular administration it is generally sold for in the peptide market has no controlled trial establishing a dose, and the skin-lightening claim it is sold on is contested in the dermatology literature.
| Human dosing established | Yes |
|---|---|
| Studied dose range | 250–1000 mg daily, oral |
| Route | Oral (the only route with controlled trial dosing) |
| Frequency | Once or twice daily |
| Duration studied | Up to 6 months in the longest controlled trial |
| Evidence level | Limited Human Evidence |
| Last reviewed | 2026-09-05 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| Systematic review — oral glutathione for skin lightening and melasmaClinical trial · Systematic review of randomised controlled trials | Participants across five randomised controlled trials and one open-arm study | 250 mg once daily, 250 mg twice daily, or 500 mg once daily | Oral | Once or twice daily | — | Melanin index, versus placebo | Glutathione as a skin-lightening agent and in melasma: a systematic review. Int J Dermatol. 2025. |
| Oral supplementation RCT (Richie et al., 2015)Clinical trial · Randomised double-blind placebo-controlled trial | Non-smoking adults (n=54) | 250 mg or 1000 mg per day | Oral | Daily | 6 months | Glutathione stores in blood, erythrocytes, plasma, lymphocytes and buccal cells | Richie JP et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr. 2015. |
| Critical review — skin whitening claimsResearch-reported · Critical review | Review of the available human evidence | No established injectable dose identified | Various | — | — | Assessment of evidence quality for skin whitening | Glutathione as a skin whitening agent: facts, myths, evidence and controversies. Indian J Dermatol Venereol Leprol. 2016. |
Where sources disagree
- Every dose above is oral. Glutathione is sold in the peptide market for intravenous or intramuscular injection, commonly at 600–2000 mg per session; no controlled trial establishes an injectable dose, and oral evidence does not transfer to injection.
- The skin-lightening effect the compound is marketed on remains contested in dermatology. The reviews cited above are explicit about small sample sizes and short follow-up, and one is titled around whether the claim is myth or verity.
- Glutathione appears as an outcome measure in thousands of trials of unrelated interventions, which inflates apparent evidence volume. Only studies that administer glutathione itself are counted here.
Reconstitution
Common research vial sizes: 600 mg, 1500 mg.
| Vial | Bacteriostatic water | Concentration | Per 0.01 mL |
|---|---|---|---|
| 600 mg | 6 mL | 100 mg/mL | 1 mg per 0.01 mL |
| 1500 mg | 10 mL | 150 mg/mL | 1.5 mg per 0.01 mL |
These figures are arithmetic only — they convert a vial and a volume into a concentration. They are not a recommendation to take any dose.
Calculate reconstitution & dose →Handling & administration
- Reconstitution Guide
- Commonly reconstituted with bacteriostatic water for research use
- Injection Sites
- Abdomen (subQ)Glute (IM)
- Concentration Example
- 600 mg vial reconstituted with 3 mL = 200 mg/mL
- Timing Notes
- Often administered on empty stomach (oral) or slow IV push/infusion
- Expected Onset
- Variable; antioxidant markers may shift within weeks
How to reconstitute Glutathione
- Check the vial size and diluent volume. The profile example for Glutathione is: Commonly reconstituted with bacteriostatic water for research use.
- Swab both vial stoppers and draw the bacteriostatic water into a sterile syringe.
- Add the water slowly down the inside wall of the peptide vial so it does not jet onto the powder, then swirl gently until the solution is clear. Do not shake.
- Record the resulting concentration: 600 mg vial reconstituted with 3 mL = 200 mg/mL.
- Label the vial with the date and concentration, refrigerate it (see Storage & stability below), and use the calculator preset to convert a dose in mcg into syringe units.
Sequence & molecular data
| Amino acid sequence | γ-L-Glutamyl-L-cysteinylglycine |
|---|---|
| Molecular formula | C10H17N3O6S |
| Molecular weight | 307.32 g/mol |
| CAS number | 70-18-8 |
| Half-life | ~1.5 hours (IV); oral bioavailability limited |
| Appearance | White crystalline powder |
| Formulation | Lyophilized Powder |
| PubChem CID | 124886 |
| FDA UNII | GAN16C9B8O |
| ChEMBL | CHEMBL1543 |
| DrugBank | DB00143 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Glutathione is a tripeptide of glutamate, cysteine and glycine and the principal intracellular thiol buffer, present in millimolar concentrations in most cells. It serves as the electron donor for glutathione peroxidases, which reduce hydrogen peroxide and lipid hydroperoxides, and as the conjugating substrate for glutathione S-transferases in phase II detoxification. The ratio of reduced to oxidised glutathione is a standard index of cellular redox state. The practical limitation is delivery: orally administered reduced glutathione is largely hydrolysed in the gut, so systemic concentrations rise little, which is why intravenous administration and precursor strategies such as N-acetylcysteine are studied instead.
Origin
Endogenous tripeptide; also produced synthetically.
Targets
Studies
- The effects of the oral supplementation of L-Cystine associated with reduced L-Glutathione-GSH on human skin pigmentation: a randomized, double-blinded, benchmark- and placebo-controlled clinical trial
- Exploring the Safety and Efficacy of Glutathione Supplementation for Skin Lightening: A Narrative Review
- Glutathione in HIV-Associated Neurocognitive Disorders
- Effects of chromium supplementation on oxidative stress biomarkers
- Bypassing the bottleneck: Gamma-glutamylcysteine supplementation for brain glutathione enrichment in Alzheimer's disease
Regulatory & research status
Glutathione is not an FDA-approved product. It is sold for laboratory research and has no approved medical use.
| FDA status | Not Approved |
|---|---|
| Availability | OTC / Supplement |
| WADA (sport) | Permitted |
| Library classification | Research-Only |
Benefits
Glutathione side effects
Glutathione has only limited human data, so the list below is incomplete and its side-effect profile is not well established.
Side Effects
- IV: asthma-like reactions rare
- Abdominal cramps (oral)
Contraindications
- Asthma (caution IV)
- Sulfur sensitivity
Stacking
Common stacking partners
Combinations that include Glutathione, with the proposed rationale, an evidence grade and what is not established, are catalogued in the peptide stacks directory.
Storage & stability
Lyophilized (freeze-dried) peptide powder is far more stable than the reconstituted solution. Keep sealed vials cold, dry and away from light; long-term storage is typically frozen, with short-term refrigeration for vials in use.
Once reconstituted in bacteriostatic water, keep the solution refrigerated, avoid repeated freeze–thaw cycles and agitation, and label the vial with the reconstitution date and concentration. Discard any solution that turns cloudy or shows particulates.
Degradation rates differ by sequence: peptides containing methionine, cysteine, asparagine or glutamine are more prone to oxidation and deamidation, so shelf life after reconstitution is compound-specific rather than universal.
Read the full guide: how to store peptides before and after reconstitution →
Source: Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. (PMID 20143256). General guidance for research handling; not product-specific instructions.
Glutathione: frequently asked questions
What is Glutathione?
Endogenous antioxidant tripeptide sold as an oral supplement and used IV in clinics. Not FDA-approved as a standalone drug for systemic “detox” or skin-lightening claims.
How does Glutathione work?
Glutathione is a tripeptide of glutamate, cysteine and glycine and the principal intracellular thiol buffer, present in millimolar concentrations in most cells. It serves as the electron donor for glutathione peroxidases, which reduce hydrogen peroxide and lipid hydroperoxides, and as the conjugating substrate for glutathione S-transferases in phase II detoxification.
Is Glutathione FDA approved?
No. Glutathione is not approved by the FDA for any indication and is categorised as otc / supplement. It has not been reviewed for safety or efficacy as a medicine, and published research should be read as investigation rather than established use.
What is the half-life of Glutathione?
Reported half-life for Glutathione is ~1.5 hours (IV); oral bioavailability limited. Half-life describes how long the compound persists in circulation, not how long any effect lasts, and published figures vary with route of administration, formulation and the population studied.
What is the amino acid sequence of Glutathione?
Glutathione has the sequence γ-L-Glutamyl-L-cysteinylglycine, giving a chain of 3 amino acids. Its molecular formula is C10H17N3O6S.
Is Glutathione banned in sport?
Glutathione is recorded here as permitted in sport. Anti-doping status is revised annually, so athletes subject to testing should confirm against the current WADA Prohibited List before use.
References
- PubChem GSHExternal reference
- The effects of the oral supplementation of L-Cystine associated with reduced L-Glutathione-GSH on human skin pigmentation: a randomized, double-blinded, benchmark- and placebo-controlled clinical trial — J Cosmet Dermatol, 2022External reference
- Exploring the Safety and Efficacy of Glutathione Supplementation for Skin Lightening: A Narrative Review — Cureus, 2025External reference
- Glutathione in HIV-Associated Neurocognitive Disorders — Curr Issues Mol Biol, 2024External reference
- Effects of chromium supplementation on oxidative stress biomarkers — Int J Vitam Nutr Res, 2023External reference
- Bypassing the bottleneck: Gamma-glutamylcysteine supplementation for brain glutathione enrichment in Alzheimer's disease — J Alzheimers Dis, 2026External reference
Related research, comparisons & guides
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Sep 6, 2026 · Version 2
This Glutathione profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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