Glutathione: Tripeptide Antioxidant Research Guide (2026)
Last updated
Introduction (research-only scope)
Glutathione is the tripeptide gamma-glutamyl-cysteinyl-glycine, present in millimolar concentrations inside most cells and central to redox balance. It is the most abundant compound in this catalog by biological ubiquity and one of the best characterised molecules in cell biology. This guide covers the biology, what our batch documentation shows, and the regulatory position.
Research use only. The material described here is a laboratory reagent for in-vitro research by qualified professionals. It is not a medicine, supplement, cosmetic ingredient or veterinary product, is not for human or animal use, and nothing on this page is medical advice or a claim of effect in any person.
What is Glutathione?
Glutathione (molecular mass 307.32, CAS 70-18-8) is unusual among peptides in carrying a gamma-linkage between glutamate and cysteine, which protects it from ordinary peptidases. Peptra Labs supplies it as a lyophilised reagent, 600 mg per vial. A note on our own batch data: the published report for batch QYA055 measured 96.43%, below the 98% specification we apply to peptides. We publish the measured value rather than a rounded claim; if your protocol requires a higher grade, ask us before ordering.
How the reported mechanism works
Redox couple
The reduced form (GSH) and the oxidised dimer (GSSG) form the cell’s main redox buffer; the GSH/GSSG ratio is a standard readout of oxidative state in cell experiments.
Synthesis and conjugation
It is synthesised in two ATP-dependent steps described in the 2013 review in Biochimica et Biophysica Acta, and it serves as the conjugating substrate for glutathione S-transferases in phase II detoxification, which is why it appears in toxicology assays.
What the published evidence covers
Unlike most compounds here, glutathione biology is textbook material rather than a contested literature: the 2017 redox theory of aging review sets out how central the couple is to current thinking. What is contested is not the biology but supplementation claims, which fall outside what a laboratory reagent page should assert. In the laboratory it is used as a redox standard, a conjugation substrate and a component of buffers.
How to verify a Glutathione research peptide is real and pure
Two tests answer two different questions: mass spectrometry confirms identity (expected molecular mass 307.32), HPLC quantifies purity. Our specification is at least 98%. The published report for batch QYA055 reported 96.43% measured purity and can be checked on the testing laboratory’s own platform: third-party verification. Match the batch number printed on your vial against the lab reports archive rather than relying on a certificate image; what a valid certificate must contain is explained in how to read a certificate of analysis.
Storage and reconstitution
Store the lyophilised material sealed, dry and protected from light at 2 to 8 °C for routine laboratory use, colder for long-term archiving. After reconstitution with bacteriostatic water, keep refrigerated and use within the window your protocol defines; repeated freeze-thaw cycles degrade peptides. General handling for all our reagents is in the peptide storage protocol.
Regulatory status
Glutathione is an endogenous compound sold in some jurisdictions as a food supplement ingredient; the reagent supplied here is neither a supplement nor a medicine and is not an authorised medicine in the European Union, the United Kingdom or the United States. It is not named on the WADA Prohibited List. Research-grade material supplied here is not a medicine and is for in-vitro laboratory use only. The wider framework, including anti-doping status, is described in the peptide risk profile.
Why labs choose our Glutathione
Batch-numbered vials, published reports where a batch has been tested, shipping from an EU warehouse with tracking (no customs inside the EU) and prices shown with VAT included. Product page: Glutathione 600 mg. Country-by-country sourcing questions are covered in the buyer guide Buy Glutathione in Europe.
References
- Lu SC. Glutathione synthesis. Biochim Biophys Acta. 2013. PubMed 22995213
- Jones DP, Sies H. Redox theory of aging: implications for health and disease. Clin Sci (Lond). 2017. PubMed 28667066