If you have been reading about glutathione and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It contains an unusual gamma-glutamyl bond between glutamate and cysteine, which resists cleavage by many peptidases. The reduced form, GSH, carries a thiol group on cysteine and is the dominant intracellular form in most cells. Its structure allows it to participate in redox reactions and to serve as a sulfur donor. The oxidized form, GSSG, consists of two GSH molecules joined by a disulfide bond.
In cells, glutathione helps maintain the reducing environment of the cytosol and supports enzymes that counteract reactive oxygen species. It acts as a cofactor for glutathione peroxidases, which reduce hydrogen peroxide and lipid peroxides, and for glutathione S-transferases, which conjugate electrophiles. The ratio of GSH to GSSG is often used as an indicator of oxidative stress, although the ratio can vary by compartment and cell type. Glutathione also stores cysteine, an amino acid that can be limiting for protein synthesis and antioxidant defense.
Glutathione is a small tripeptide made of glutamic acid, cysteine, and glycine. Its cysteine thiol group allows reversible oxidation and reduction, making it central to cellular redox chemistry. The reduced form, often abbreviated GSH, predominates inside most cells, while the oxidized disulfide form, GSSG, forms when two GSH molecules react. The ratio of GSH to GSSG is widely used as an indicator of oxidative stress in laboratory research, though it does not by itself diagnose a clinical condition.
Biosynthesis occurs in two ATP-dependent steps. The enzyme glutamate-cysteine ligase joins glutamate and cysteine, forming gamma-glutamylcysteine; glutathione synthetase then adds glycine to produce the complete tripeptide. Because the peptide bond from glutamate uses the gamma-carboxyl group, glutathione resists digestion by many ordinary peptidases. Tissues vary in synthesis capacity, and the liver generally contains high concentrations relative to many other organs. This uneven distribution contributes to organ-specific differences in redox buffering and affects how experimental results are interpreted across tissue types.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C10H17N3O6S | For reduced glutathione; the oxidized dimer has two sulfur atoms. |
| Molar mass | 307.32 g/mol | Calculated for the reduced form. |
| Appearance | White to off-white crystalline powder | Typical for solid reagent; solutions are usually colorless. |
| Solubility | Freely soluble in water | Poorly soluble in nonpolar organic solvents. |
| Typical storage | -20 °C, desiccated, protected from light | Limits oxidation, moisture uptake, and degradation. |
Accurate measurement of glutathione begins with careful sample handling. Because GSH oxidizes rapidly to GSSG, samples must be processed quickly or frozen immediately. Acid precipitation with metaphosphoric acid or perchloric acid is common; it lowers pH, precipitates proteins, and helps preserve the reduced form. Chelating agents such as EDTA can limit metal-catalyzed oxidation. For whole blood, hemolysis releases glutathione from erythrocytes, so plasma and serum values differ substantially from whole blood values.
Several analytical methods can quantify glutathione, including high-performance liquid chromatography (HPLC) with UV or fluorescence detection for separating GSH and GSSG. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers higher specificity and sensitivity, often detecting nanomolar concentrations. The enzymatic recycling assay, often called the Tietze method, measures total glutathione by coupling reduction of GSSG to a colorimetric or fluorometric readout. Capillary electrophoresis and electrochemical detection are also used in specialized laboratories. Each method has distinct advantages and limitations regarding throughput, cost, and susceptibility to interference.
Glutathione is a small tripeptide built from glutamic acid, cysteine, and glycine. Its peptide bond between glutamate and cysteine involves the gamma-carboxyl group rather than the usual alpha-carboxyl group. This structure gives the molecule a reactive thiol on the cysteine residue. The reduced form, often abbreviated GSH, is the predominant intracellular species in many cell types. Because the thiol can donate electrons, glutathione participates in redox chemistry and in the conjugation of reactive molecules.
Cells synthesize glutathione through two ATP-dependent steps: glutamate-cysteine ligase joins glutamate and cysteine, and glutathione synthetase adds glycine to form the complete tripeptide. Breakdown occurs through gamma-glutamyl transpeptidase and subsequent peptidase reactions, forming the gamma-glutamyl cycle. Within cells, glutathione also forms a disulfide-linked dimer called GSSG when two GSH molecules react. The balance between GSH and GSSG is widely used as an indicator of oxidative conditions, although the ratio can vary by compartment and tissue.
=== Generative Merkmale === Die Blütezeit reicht von Juni bis August. Der Blütenstiel ist schlank und behaart. Die relativ große Blütenknospe ist meist 15 bis 25 (10 bis 30) Millimeter lang und hängt über. Beim Öffnen der Blütenknospe fallen die zwei Kelchblätter ab. Die geöffneten, zwittrigen Blüten sind bei einem Durchmesser von 5 bis 10 Zentimetern radiärsymmetrisch. Die vier weißen bis violetten (selten roten) Blütenkronblätter sind etwa doppelt so groß wie die Kelchblätter und weisen am Grund einen dunklen Fleck auf. Die Staubblätter sind in gelbe Staubfäden und 2 bis 4 Millimeter lange Staubbeutel gegliedert. Die Blüte ist meist schon nach wenigen Tagen komplett bestäubt und wirft dann auch ihre Blütenkronblätter ab. Die Blüten von Ziermohnrassen können andersfarbig sein und mehr als vier Blütenkronblätter besitzen. Die kugeligen Kapselfrüchte enthalten hunderte Samen. Die relativ kleinen Samen sind nierenförmig, hart, erhaben netzartig geadert und grubig vertieft. Stahlblaue Samen sind der Wildform am ähnlichsten, weißliche Samen enthalten weniger Öl und werden zur Mehlherstellung verwendet. Eine Sorte mit grauen Samen (Waldviertler Graumohn) ist in Österreich populär und dessen Herkunftsbezeichnung geschützt. Die Tausendkornmasse beträgt nur etwa 0,3 bis 0,7 Gramm. Die Chromosomenzahl beträgt 2n = 22 oder 44.
== Standortbedingungen == Die ökologischen Zeigerwerte nach Landolt et al. 2010 sind in der Schweiz: Feuchtezahl F = 2+ (frisch), Lichtzahl L = 4 (hell), Reaktionszahl R = 3 (schwach sauer bis neutral), Temperaturzahl T = 4 (kollin), Nährstoffzahl N = 4 (nährstoffreich), Kontinentalitätszahl K = 3 (subozeanisch bis subkontinental). Der Schlafmohn wird in den Alpentälern bis in Meereshöhen von 1600 Metern angebaut.
=== Taxonomie === Die Erstveröffentlichung von Papaver somniferum erfolgte 1753 durch Carl von Linné in Species Plantarum, Tomus I, Seite 508. Das Artepitheton somniferum leitet sich aus dem Lateinischen ab und bedeutet „Schlaf bringend“; es verweist auf die Verwendung als Schlafmittel für Kinder in der griechischen Antike. Synonyme für Papaver somniferum L. sind: Papaver album Mill., Papaver hortense Hussenot nom. illeg., Papaver officinale C.C.Gmel., Papaver somniferum var. nigrum DC., Papaver somniferum subsp. nigrum (DC.) Thell., Papaver somniferum subsp. nigrum Schübl. & G. Martens, Papaver somniferum subsp. hortense Arcang., Papaver somniferum subsp. hortense (Hussenot) Corb., Papaver somniferum subsp. songaricum Basil.
Sources: de.wikipedia.org
Papaver somniferum L. subsp. somniferum: Die Chromosomenzahl ist 2n = 22 oder 44. Papaver somniferum subsp. setigerum (DC.) Arcangeli (Syn.: Papaver setigerum DC.): Sie kommt in Südeuropa, Nordafrika, Vorderasien und in Makaronesien vor. Die Chromosomenzahl beträgt 2n = 22 oder 44. Papaver somniferum subsp. songaricum Basil.: Sie kommt auf der Balkanhalbinsel und in Asien vor.
Sources: de.wikipedia.org
GSH is the reduced form with a free thiol group, while GSSG is the oxidized disulfide-linked dimer. Most assays distinguish the two because their balance reflects redox conditions. The names are not interchangeable.
It is synthesized in the body from amino acids, so it is not classified as an essential dietary nutrient for most people. Dietary and supplemental forms are studied for their effects on tissue levels and health markers. Evidence varies by population and outcome.
The phrase highlights its high intracellular concentration and its role in several antioxidant and detoxification reactions. It is not the only antioxidant, and the term can oversimplify its functions. Scientific descriptions usually specify the pathway or enzyme involved.
GSH is the reduced form of glutathione, with a free thiol group on cysteine. GSSG is the oxidized disulfide form, created when two GSH molecules become linked. The two forms exist together, and their balance is often reported as the GSH/GSSG ratio in laboratory studies.