Glutathione

The row below carries a price per mg figure: listed price divided by stated peptide content, excluding shipping and codes. It is the same calculation applied on every compound page, so a figure here is directly comparable to one anywhere else on the site.

We currently track a single listing for this compound. When a second vendor is added the rows are ordered by measured $/mg, and the flags for testing and shipping are computed from the data shown. Each row carries its own verification date.

N[C@@H](CCC(=O)N[C@@H](CS)C(=O)NCC(O)=O)C(O)=O

Appearance : white crystalline powder Melting point : 195 °C Solubility, water : freely soluble Solubility, other : insoluble in methanol and diethyl ether

Glutathione is a tripeptide, but it is not a conventional one. The bond joining glutamate to cysteine is formed through the side-chain carboxyl of glutamate rather than the standard alpha-amino linkage — a gamma-glutamyl bond.

That distinction has practical consequences. The gamma linkage is not recognized by most peptidases, so glutathione resists the intracellular degradation that would rapidly clear a standard tripeptide. Cleavage instead requires gamma-glutamyltransferase, an enzyme localized to the external surface of cell membranes.

Correct nomenclature therefore includes the gamma prefix: γ-L-Glutamyl-L-cysteinyl-glycine. Writing it as "L-glutamyl-L-cysteinyl-glycine" describes a different molecule.

Glutathione is supplied and sold in two chemically distinct forms. They are separate compounds with separate registry entries.

GSSG is a disulfide of two GSH molecules, joined through their cysteine thiols. The reduced form is the active antioxidant; the oxidized form is the spent product, recycled back to GSH by glutathione reductase. The GSH/GSSG ratio is used in the literature as an index of oxidative stress.

Material listed on this page is the reduced form (CAS 70-18-8), which the CAS, formula, and molecular weight together confirm. Suppliers stocking both forms list them as separate SKUs, and a page citing GSH literature while shipping GSSG would be describing the wrong molecule.

γ-L-Glutamyl-L-cysteine (GGC) — CAS 636-58-8, C8H14N2O5S, 250.27 g/mol, PubChem CID 123938. The intermediate formed before glycine is added to complete the tripeptide.

Glutathione is synthesized endogenously rather than obtained preformed from diet, assembled in two ATP-dependent steps from glutamate, cysteine, and glycine. Cysteine availability is the usual rate-limiting factor.

The reactive centre is the cysteine thiol. Through it, glutathione serves as electron donor in the reduction of peroxides and as the nucleophile in conjugation reactions.

Reduces hydrogen peroxide and lipid hydroperoxides, oxidizing two GSH to one GSSG in the process.

Catalyses conjugation of glutathione to electrophilic substrates — Phase II metabolism — increasing water solubility for excretion.

Regenerates GSH from GSSG using NADPH, maintaining the intracellular redox pool.

Uses glutathione as cofactor in detoxifying methylglyoxal, a reactive dicarbonyl byproduct of glycolysis.

Glutathione participates in the recycling of other antioxidants, including ascorbate and alpha-tocopherol, extending their activity.

Glutathione has a substantially larger literature than most compounds in this category, reflecting its status as an endogenous metabolite rather than a synthetic analog. Work spans redox biochemistry, hepatology, metabolic research, dermatology, and analytical method development.

A randomized controlled trial examined whether oral supplementation raises body glutathione stores (Richie 2015). Bioavailability is a recurring question in this literature, since glutathione is subject to hydrolysis in the gastrointestinal tract.

A three-week oral supplementation study examined whole-body insulin sensitivity in obese males with and without type 2 diabetes (Søndergård 2021).

An open-label, single-arm, multicenter pilot study examined glutathione in nonalcoholic fatty liver disease (Honda 2017).

A randomized, double-blind, placebo-controlled study examined oral glutathione in relation to skin pigmentation (Arjinpathana 2012). The proposed mechanism in this literature is tyrosinase inhibition and a shift in melanin synthesis from eumelanin toward pheomelanin.

Glutathione metabolism and its implications for health (Wu 2004) is the standard reference review for the pathway.

Beyond investigation as a subject compound, glutathione functions as a reference standard in redox assays, a substrate in glutathione-S-transferase activity measurement, and a component of affinity purification systems for GST-tagged proteins.

Glutathione occupies a different position from synthetic research peptides. It is an endogenous human metabolite, present in every cell, and is widely available as an oral dietary supplement ingredient in the United States.

There is no FDA-approved glutathione drug product in the United States. The World Health Organization has assigned the ATC code V03AB32, placing it among antidotes, reflecting approved use in certain other jurisdictions.

Material supplied for laboratory use is a research chemical. It is not a drug, food, cosmetic, or dietary supplement as supplied, has not been evaluated by the FDA in that form, and is not intended for human or veterinary use.