glutathione comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-12-24. Numbers and descriptions here follow the published literature rather than marketing material.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. Its cysteine residue carries a thiol group, which allows the molecule to participate in reduction and oxidation reactions. The compound exists in most living cells, where the reduced form, often abbreviated GSH, is usually more abundant than the oxidized disulfide form, GSSG. Intracellular concentrations are commonly in the millimolar range, while extracellular concentrations are much lower. This uneven distribution supports its role as a major cellular redox buffer.
Cells synthesize glutathione through two ATP-dependent enzymatic steps. The first step combines glutamate and cysteine to form gamma-glutamylcysteine, catalyzed by glutamate-cysteine ligase. The second step adds glycine, producing the complete tripeptide, catalyzed by glutathione synthetase. Glutathione itself can inhibit the first enzyme, providing negative feedback when levels are high. Because cysteine is often limiting, its availability influences how quickly the pathway proceeds. These reactions occur in the cytosol, and the resulting glutathione can be distributed to other compartments.
Glutathione functions in redox balance, detoxification, and sulfur amino acid storage. It participates in reactions that help maintain ascorbate and protein thiol status. The molecule serves as a cofactor for several enzymes, including glutathione peroxidases and glutathione S-transferases. These enzymes reduce peroxides and conjugate electrophiles, respectively. Glutathione also contributes to the metabolism of xenobiotics and to the transport of cysteine between tissues. How interorgan transport and tissue-specific regulation shape whole-body pools remains an active area of study.
Samples for glutathione analysis require careful handling because the compound oxidizes readily and can be consumed by enzymes after collection. Blood is often treated with acid or thiol-blocking agents soon after draw, and plasma should be separated quickly from red blood cells. Tissues are usually snap-frozen or extracted immediately. Aqueous solutions of glutathione are less stable than dry powder and degrade faster at neutral or alkaline pH, in light, or with dissolved oxygen. Repeated freeze-thaw cycles also reduce reliability.
Quality control for glutathione materials checks identity, assay, purity, water content, and disulfide content. Commercial products vary from research-grade powder to dietary supplements, and labels may not distinguish reduced from oxidized forms. In the United States, oral glutathione is commonly sold as a dietary supplement rather than an approved drug, while injectable forms fall under different rules and may require a prescription. Regulatory status differs by country. Analytical certificates, when available, help verify what a material contains, but independent testing remains important for interpretation.
Laboratory measurement of glutathione typically starts with rapid acid extraction to prevent oxidation and enzymatic degradation. Common methods include enzymatic recycling assays, high-performance liquid chromatography, and liquid chromatography coupled with mass spectrometry. The recycling assay uses glutathione reductase and a thiol-reactive colorimetric or fluorescent reagent, measuring total glutathione after converting disulfide forms. Chromatographic methods can separate reduced and oxidized forms, which helps when the redox ratio is the target. Choice of method affects sensitivity, specificity, and the amount of sample needed.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C10H17N3O6S | Reduced glutathione (GSH) |
| Molar mass | 307.32 g/mol | Calculated for C10H17N3O6S |
| Appearance | White to off-white powder | Typical solid form |
| Solubility | Water-soluble | Polar tripeptide |
| Common synonyms | GSH; L-glutathione | Gamma-glutamylcysteinylglycine |
Synthesis occurs in two ATP-dependent steps. The enzyme glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine. The first step is rate-limiting and is influenced by cysteine availability and feedback inhibition by GSH. Breakdown involves gamma-glutamyl transferase and subsequent peptidases, which release constituent amino acids for reuse. Because turnover differs among tissues, measurements from blood, plasma, and tissues are not directly interchangeable. Research continues to clarify how compartment-specific pools are regulated in health and disease.
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.
Commercial glutathione is produced by microbial fermentation or chemical synthesis, then purified. Reduced and oxidized grades are offered separately, with purity specifications often exceeding 98 percent. The compound appears in foods such as fresh fruits, vegetables, and meats, although cooking and processing can lower amounts. Oral, topical, and inhaled forms are discussed in research and consumer contexts, but absorption and tissue delivery remain active areas of study. Regulatory status varies by country and intended use.
Glutathione is a small sulfur-containing peptide built from glutamic acid, cysteine, and glycine. Its distinctive feature is a gamma-glutamyl bond between glutamate's side-chain carboxyl group and cysteine's amino group. This linkage resists ordinary peptidases and helps the molecule remain stable inside cells. The reduced thiol form, often abbreviated GSH, is the dominant intracellular species. The oxidized disulfide dimer, GSSG, forms when two reduced molecules link through their cysteine sulfur atoms. The balance between these forms is a common redox indicator.
Die Frau von Meenybraddan ist eine Moorleiche, die 1978 im Meenybraddan Bog (irisch Mín Uí Bhradáin), nahe der Ortschaft Inver (Inbhear) im irischen County Donegal, gefunden wurde. Sie befindet sich heute im Irischen Nationalmuseum in Dublin.
== Fundort == Das Meenybraddan Bog (Moor) liegt inmitten einer weitläufigen Hochmoorlandschaft mit einer Ausdehnung von etwa 400 km². Hier wurde 1942 erstmals Torf abgebaut. Im Bereich der Fundstelle begann der Abbau 1974. Das Moor hatte hier eine Tiefe von mehr als zwei Metern. Die Fundstelle selbst liegt in 300 m Entfernung zur Verbindungsstraße Ardara – Inver und etwa 60 m westlich eines Bog Road genannten Feldweges zwischen Dunkineely und Glenties.Fundort:
== Fundgeschichte == Die Frau von Meenybraddan wurde am frühen Nachmittag des 3. Mai 1978 von dem Bauern Frank Battles und einigen Nachbarn entdeckt. Beim manuellen Torfstechen stießen sie in einer Tiefe von etwa einem Meter auf die in ein Stoffstück eingewickelte Leiche. Sie wurde geborgen und in das Sheil Hospital in Ballyshannon gebracht, wo sie am späten Nachmittag von einem Polizisten aus Mountcharles begutachtet wurde. Am 5. Mai meldete der Leiter der Polizeidienststelle den Fund an die Gerichtsmedizin und das Irische Nationalmuseum, und am nächsten Tag untersuchten zwei Gerichtsmediziner sowie ein Konservator des Nationalmuseums die Leiche und den Fundplatz. Der Gerichtsmediziner Dr. Harbison fertigte noch einige Röntgenaufnahmen an, und am gleichen Abend wurde der Fund nach Dublin transportiert, wo er im städtischen Leichenhaus in einer Kühlkammer gelagert wurde.
== Wissenschaftliche Bearbeitung == Am 23. Mai wurde die Leiche von einem neunköpfigen interdisziplinären Expertenteam untersucht. Da sie bereits leichte Veränderungen durch das Auftauen und Trocknen zeigte, wurde sie in das Dubliner St. James Krankenhaus gebracht und in einer Leichenkühlzelle bei −4 °C eingefroren. In den folgenden Tagen wurde ein Computertomogramm ihres Körpers angefertigt. Am 6. Juni 1978 untersuchte ein Zahnmediziner das Gebiss, und bei einer oberflächlichen Untersuchung der Haut wurde erstmals ein Schimmelpilzbefall beobachtet. Am 13. Juni 1978 ergab eine endoskopische Untersuchung eine weitere Verschlechterung des Erhaltungszustandes, woraufhin alle weiteren geplanten Untersuchungen abgesagt wurden. Zur Stabilisierung wurde die Leiche in einer Tiefkühlkammer der Dubliner Gerichtsmedizin gelagert. Sieben Jahre später, am 22. Juli 1985, wurde die Frau von Meenybraddan in einem speziell angefertigten und mit Trockeneis gekühlten Transportbehälter in die Konservierungswerktätten für organisches Material des Britischen Museums nach London transportiert. Im August 1985 wurde die Leiche aufgetaut und erneut untersucht. Für die spätere Konservierung wurden ihr die inneren Organe entnommen und separat konserviert. Der Körper der Frau wurde mit Polyethylenglykol imprägniert und gefriergetrocknet. Die Konservierung war am 11. November 1985 abgeschlossen, und der Fund konnte am 28. Mai 1987 an das Irische Nationalmuseum überführt werden.
Sources: de.wikipedia.org
Glutathione is built from three amino acids: glutamate, cysteine, and glycine. The linkage involves the gamma-carboxyl group of glutamate rather than the alpha-carboxyl group, which is unusual for peptides. This structure protects the bond from some common peptidases.
It is present in nearly all cells, with notable amounts in the liver, kidneys, and red blood cells. The highest intracellular concentrations are usually in the millimolar range. Levels differ by tissue, age, and physiological state.
It is not classified as an essential nutrient because cells can synthesize it from amino acids. Dietary sources exist, but their contribution to tissue pools is not fully established. The body's production depends on enzyme activity and precursor availability.
Common approaches include enzymatic recycling assays, HPLC, and LC-MS/MS. Acid extraction and rapid processing limit oxidation before analysis.