How to Read a Glutathione Certificate of Analysis (COA)
A Certificate of Analysis is only useful if you know which number on it matters for the compound in front of you. For Glutathione, the informative checks are not the same as for a generic short peptide.
Overview
On a certificate, look for reduced glutathione at about 307 and check how much oxidised glutathione (about 613) is there. The certificate for this batch is available on request.
What Glutathione actually is
Glutathione is a very small peptide — just three building blocks, glutamate, cysteine and glycine — that nearly every cell makes for itself. Its sulfur group grabs reactive oxygen, which makes it the main built-in antioxidant researchers measure when they study oxidative stress. This is the reduced form, called GSH.
Supplied for laboratory research use only — not for human or animal use.
Third-party tested by HPLC and LC-MS, ≥99% purity, with a Certificate of Analysis available on request. Ships across Canada.
Technical detail below
Assays that are informative for Glutathione
What to check on the COA
Check that the main peak is reduced GSH (about 307.3 Da) and look for a GSSG peak (about 612.6 Da) — the GSH:GSSG ratio is the real quality indicator for this compound. Content per vial matters more than usual at a 1500 mg fill.
Glutathione disulfide (GSSG), γ-glutamyl-cysteine, cysteinyl-glycine and free cysteine.
Verify a Popular Peptides batch
Every batch is third-party tested by HPLC and LC-MS with a published Certificate of Analysis (≥99% purity). Enter a lot number to pull the COA for the exact vial in front of you.
What Glutathione is studied for
Glutathione is the most abundant low-molecular-weight thiol in most cells, and the ratio of reduced to oxidised glutathione is widely used as a read-out of oxidative stress in cell-culture and tissue studies.
Meister and Anderson (Annu Rev Biochem 1983) reviewed glutathione synthesis by γ-glutamylcysteine synthetase and glutathione synthetase, and its breakdown by γ-glutamyl transpeptidase — the framework most synthesis and turnover studies still use.
GSTs conjugate glutathione to electrophilic compounds, and this conjugation step is a standard model in xenobiotic-metabolism research.
Glutathione peroxidases use GSH to reduce hydrogen peroxide and lipid hydroperoxides, with glutathione reductase recycling GSSG back to GSH using NADPH — a common model for studying peroxide handling in vitro.
Summarizes published preclinical literature — see the selected references below. Provided for research reference only; not a claim of efficacy or a description of human use.
References describe in-vitro and preclinical research and are listed for reference only — not evidence of efficacy and not a description of human use.
More Glutathione reference
Lyophilized and reconstituted storage conditions, plus the practical working window.
Diluent selection, dissolution behaviour, and the calculator preset for this compound.
Which solvents work, why, and what abnormal dissolution behaviour indicates.
The specific chemical routes by which this molecule breaks down, and how to limit each.
Compound-specific bench practices, and the errors most often made with this molecule.
What to inspect on arrival, and which conditions actually warrant rejecting a vial.
Questions specific to this compound — structure, chemistry, and common misconceptions.
Purity & COA reference for other compounds
Reviewed for research-use compliance by Kobi Williams, Founder — Popular Peptides Canada. Last reviewed 22 July 2026.
Glutathione is supplied strictly as a research chemical for in-vitro laboratory and research use only. It is not intended for human or animal consumption, diagnostic, or therapeutic use. This page is educational laboratory-handling reference information — not medical advice, not usage guidance, and not a protocol.