Glutathione (GSH) is the tripeptide γ-L-glutamyl-L-cysteinyl-glycine, formula C10H17N3O6S and molecular weight 307.33 g/mol.[1] It is the most abundant non-protein thiol in mammalian tissues and a cen...
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Certificate of Analysis included with every order.
Technical Specifications
Purity
≥98%
Form
Lyophilized Powder
Storage
-20°C
Molecular Weight
307.33 g/mol (C10H17N3O6S, reduced GSH)
Sequence
γ-Glu-Cys-Gly (γ-L-glutamyl-L-cysteinyl-glycine)
CAS Number
70-18-8
About Glutathione
Glutathione (GSH) is the tripeptide γ-L-glutamyl-L-cysteinyl-glycine, formula C10H17N3O6S and molecular weight 307.33 g/mol.[1] It is the most abundant non-protein thiol in mammalian tissues and a central molecule in defense against oxidative stress, redox signaling and detoxification of xenobiotics.[3] Pepitiva supplies glutathione as a lyophilized powder (600 mg vials, ≥98% purity) for in vitro and preclinical research.
Reduced and oxidized forms
The reduced form (GSH, CAS 70-18-8) carries a free thiol on its cysteine; two GSH molecules oxidize to glutathione disulfide (GSSG, 612.6 g/mol).[1][8] The balance between the two is used as a readout of cellular redox state, and methods for measuring GSH status are an established part of the field.[2][5]
Why researchers study glutathione
Glutathione protects cells from oxidative damage and from toxic electrophiles, by reducing oxidants and by conjugating electrophiles.[2] Dysregulated glutathione synthesis has been linked to diabetes, pulmonary and liver fibrosis, alcoholic and cholestatic liver injury, endotoxemia and drug-resistant tumor cells.[3]
For research use only. Not for human consumption.
Quality & Storage
≥98% purity. Lyophilized Powder. Storage: -20°C. For research purposes only.
Mechanism of Action
Antioxidant and conjugation chemistry
GSH eliminates oxidants by reduction and removes electrophiles by conjugation, and it helps maintain redox homeostasis.[2] In oxidizing conditions it is converted to GSSG, and a fall in the GSSG-to-GSH ratio has been used as an indicator of reduced oxidative stress.[5]
Biosynthesis
Cells make glutathione in the cytosol in two enzymatic steps. Glutamate cysteine ligase (GCL), made of a catalytic (GCLC) and a modifier (GCLM) subunit, is the rate-limiting enzyme, followed by glutathione synthetase (GS). Cysteine availability and GCL activity are the key determinants of synthesis, and the genes are regulated by Nrf2 through the antioxidant response element, by AP-1 and by NF-κB.[3]
Fate of oral glutathione
In healthy volunteers, a single oral dose did not significantly raise plasma glutathione, cysteine or glutamate over 270 minutes, which the authors attributed to hydrolysis by intestinal and hepatic γ-glutamyltransferase.[4] A later 6-month randomized trial found that daily oral glutathione increased glutathione stores in blood, erythrocytes, plasma and lymphocytes, with levels returning to baseline after a 1-month washout.[5]
Research Applications
Research findings
Systemic availability (1992): no significant rise in circulating glutathione after a single oral dose in 7 volunteers.[4]
Body stores (2015): in a 6-month trial in 54 adults, glutathione rose by 30 to 35% in erythrocytes, plasma and lymphocytes in the higher-dose group, the GSSG-to-GSH ratio fell, and natural killer cytotoxicity more than doubled at 3 months.[5]
Skin lightening (reviews, 2025 and 2026): a systematic review found that topical and oral glutathione reduced the melanin index in some trials, but described intravenous use as contraindicated because of lack of efficacy and side effects; a 2026 review concluded that the evidence for intravenous glutathione is too limited to justify routine use and noted hepatotoxicity, hypersensitivity and possible renal and endocrine effects.[6][7]
Laboratory research applications
Redox biology: GSH/GSSG measurements as indicators of oxidative stress in cells and tissues.[2][5]
Detoxification studies: conjugation of electrophiles and xenobiotics.[2][3]
Regulation of synthesis: GCL and GS expression, Nrf2/ARE signaling, and cysteine supply.[3]
Disease models: liver injury, fibrosis and drug-resistant tumor cells, where glutathione synthesis is dysregulated.[3]
Related research compounds: the copper peptide GHK-Cu and methylcobalamin (vitamin B12) are other compounds studied in cellular metabolism and tissue models.
The human findings above are scientific background only. This product is sold for laboratory research and is not intended for human or veterinary use.
Storage & Handling Guidelines
Proper storage and handling are essential to maintain peptide integrity and ensure reliable research results. All Pepitiva Biolabs peptides are supplied as lyophilized (freeze-dried) powder, which provides excellent long-term stability when stored correctly. Store lyophilized peptides at -20°C for long-term storage or 2-8°C for short-term use. Once reconstituted, peptide solutions should be stored at 2-8°C and used within the timeframe specified in the product documentation. Always use sterile bacteriostatic water for reconstitution and handle peptides in a clean laboratory environment to prevent contamination. Avoid repeated freeze-thaw cycles, as thermal stress can cause peptide degradation and loss of biological activity.
Quality Control & Certification
This product is manufactured under strict quality control protocols and has been verified through comprehensive analytical testing. Each batch undergoes reverse-phase HPLC analysis for purity determination and electrospray ionization mass spectrometry (ESI-MS) for molecular identity confirmation. A detailed Certificate of Analysis (COA) is available for download, documenting purity percentage, molecular weight verification, appearance, and recommended storage conditions. Pepitiva Biolabs maintains batch-level traceability from synthesis through delivery, ensuring complete transparency and quality assurance for your research.
Frequently Asked Questions
What is glutathione?
A tripeptide, γ-L-glutamyl-L-cysteinyl-glycine, and the most abundant non-protein thiol in mammalian tissues. It protects cells against oxidants and electrophiles and helps maintain redox balance.
What is the molecular weight and CAS number of glutathione?
Reduced glutathione (GSH): 307.33 g/mol, formula C10H17N3O6S, CAS 70-18-8 (PubChem CID 124886). The oxidized form, glutathione disulfide (GSSG), is 612.6 g/mol.
What is the difference between reduced (GSH) and oxidized (GSSG) glutathione?
GSH has a free thiol group; when it neutralizes oxidants, two GSH molecules join through a disulfide bond to form GSSG. The GSSG-to-GSH ratio is used as a marker of oxidative stress.
Is oral glutathione absorbed?
Results differ by study design. A single oral dose did not raise plasma glutathione in healthy volunteers, but a 6-month randomized trial of daily oral glutathione found increased stores in blood cells and plasma.
Does glutathione lighten skin?
Evidence is limited. Some trials of topical and oral glutathione reported a lower melanin index, but reviews consider intravenous use unsupported and raise safety concerns.
How should glutathione lyophilized powder be stored?
Keep the lyophilized powder at −20 °C, protected from light and moisture.
Is this product approved for human use?
No. This product is intended exclusively for in vitro scientific research and laboratory use. It is not approved for human or veterinary use, not intended for diagnostic or therapeutic purposes, and should not be administered to humans or animals under any circumstances.
How do I reconstitute this peptide?
Add sterile bacteriostatic water slowly to the vial, directing the stream against the glass wall rather than directly onto the lyophilized powder. Gently swirl the vial until the powder is fully dissolved — do not shake vigorously. The recommended reconstitution volume depends on your desired concentration. Refer to the product documentation for specific guidance.
Can I get a Certificate of Analysis (COA)?
Yes. A Certificate of Analysis is included with every order and is also available for download from the product page. The COA documents HPLC purity, mass spectrometry identity confirmation, batch number, production date, and storage recommendations.
Forman HJ, Zhang H, Rinna A. Glutathione: overview of its protective roles, measurement, and biosynthesis. Mol Aspects Med. 2009;30(1-2):1-12. PubMed
Lu SC. Glutathione synthesis. Biochim Biophys Acta. 2013;1830(5):3143-3153. PubMed
Witschi A, Reddy S, Stofer B, Lauterburg BH. The systemic availability of oral glutathione. Eur J Clin Pharmacol. 1992;43(6):667-669. PubMed
Richie JP Jr, Nichenametla S, Neidig W, et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. Eur J Nutr. 2015;54(2):251-263. PubMed
Sarkar R, Yadav V, Yadav T, et al. Glutathione as a skin-lightening agent and in melasma: a systematic review. Int J Dermatol. 2025;64(6):992-1004. PubMed
Aloraini K, Alangari A, Arif J, Alkhodairy F. Glutathione for skin lightening via intravenous, oral, and topical routes: a critical narrative review of current evidence, safety, and the evidence-practice gap. J Med Life. 2026;19(7):511-523. PubMed
Sources are peer-reviewed publications indexed in PubMed and trial registrations on ClinicalTrials.gov. Each citation was checked against its PubMed record.
For research use only. Not for human consumption.
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