If you have been reading about GSSG 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.
Updated 2026-07-02. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Glutathione supports several cellular processes beyond direct antioxidant action. It serves as a cofactor for glutathione peroxidase and glutathione S-transferase enzymes, which reduce peroxides and conjugate electrophiles, respectively. The molecule also acts as a reservoir of cysteine, an amino acid that can limit protein synthesis and redox signaling. In human nutrition, oral glutathione is sold as a supplement, but how much intact glutathione reaches tissues after ingestion remains an active research question. Clinical claims about supplementation are not uniformly supported by controlled trials.
Functionally, glutathione supports redox balance by donating electrons and becoming oxidized. It also serves as a cofactor for enzymes such as glutathione peroxidases and glutathione S-transferases. These enzymes participate in peroxide reduction and in conjugation reactions that help process reactive molecules. Separate from antioxidant roles, glutathione can modify protein cysteines through S-glutathionylation, influencing enzyme activity and signaling. Research continues to examine how these chemical roles translate into whole-organism effects.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. Its glutamate-cysteine linkage uses the gamma-carboxyl group of glutamate, a feature that resists standard peptidases. The cysteine residue provides a thiol group, which gives the molecule its reducing character. In cells, glutathione is often the most abundant small-molecule thiol, with concentrations varying widely by tissue and compartment. It exists mainly in a reduced form called GSH, while oxidation produces a disulfide-linked dimer called GSSG.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C10H17N3O6S | Reduced form; oxidized dimer is C20H32N6O12S2 |
| Molar mass | 307.32 g/mol | For reduced glutathione (GSH) |
| Appearance | White crystalline powder | Typical laboratory and supplement-grade material |
| Solubility | Soluble in water | Poorly soluble in ethanol and other nonpolar solvents |
| Typical storage | -20 C, desiccated, protected from light | Reduced form can oxidize in solution |
Glutathione synthesis proceeds in two ATP-dependent steps catalyzed by glutamate-cysteine ligase and glutathione synthetase. The first step joins glutamate and cysteine to form gamma-glutamylcysteine and is generally rate-limiting. The second step adds glycine to complete the tripeptide. Cysteine availability, feedback inhibition by glutathione, and oxidative conditions influence flux through this pathway. The pathway is conserved across many organisms, and degradation by gamma-glutamyl transpeptidase and related peptidases recycles amino acids for new synthesis.
Within cells, glutathione serves as a cofactor for glutathione peroxidases and glutathione S-transferases. These enzymes reduce hydrogen peroxide and organic peroxides or conjugate electrophilic compounds to the thiol group. The resulting conjugates can be exported and processed through mercapturic acid pathways. Glutathione also contributes to protein thiol homeostasis and to recycling of other antioxidants such as ascorbate. Its precise roles vary by tissue, and many regulatory effects observed in laboratory systems remain difficult to quantify in whole organisms.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. The peptide bond between glutamate and cysteine uses the gamma-carboxyl group of glutamate rather than the alpha-carboxyl group. This unusual linkage protects the molecule from many common peptidases. The cysteine side chain carries a thiol group that can undergo reversible oxidation. Because of this thiol, glutathione participates in redox reactions and helps maintain the reducing environment inside most cells in living systems.
In cells, glutathione exists mainly in a reduced form called GSH. When two GSH molecules react, they form oxidized glutathione, or GSSG, which contains a disulfide bond. The ratio of GSH to GSSG is often used as an indicator of oxidative stress. Enzymes such as glutathione peroxidase and glutathione reductase help cycle the molecule between these two states. This cycling supports antioxidant defense, detoxification of reactive molecules, and regulation of certain signaling pathways.
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.
=== Total thyroxine === Total thyroxine is rarely measured, having been largely superseded by free thyroxine tests. Total thyroxine (Total T4) is generally elevated in hyperthyroidism and decreased in hypothyroidism. It is usually slightly elevated in pregnancy secondary to increased levels of thyroid binding globulin (TBG). Total T4 is measured to see the bound and unbound levels of T4. The total T4 is less useful in cases where there could be protein abnormalities. The total T4 is less accurate due to the large amount of T4 that is bound. The total T3 is measured in clinical practice since the T3 has decreased amount that is bound as compared to T4. Reference ranges depend on the method of analysis. Results should always be interpreted using the range from the laboratory that performed the test. Example values are:
=== Historical use in psychiatry and psychotherapy === LSD was subject to exceptional interest within the field of psychiatry in the 1950s and early 1960s, and Sandoz distributed LSD to researchers under the trademark name Delysid in an attempt to find a marketable use for it. During this period, LSD was controversially administered to hospitalised schizophrenic autistic children, with varying degrees of therapeutic success. It was said to have been tried in every type of mental disorder by 1960. LSD was also used in an attempt to cure homosexuality. Most of the early studies of LSD for psychiatric conditions were of very low quality, often lacking even control groups. In 1975, it was concluded that LSD showed little difference from placebo for most conditions. LSD-assisted psychotherapy was used in the 1950s and early 1960s by psychiatrists such as Humphry Osmond, who pioneered the application of LSD to the treatment of alcoholism, with promising results. Osmond coined the term "psychedelic," meaning "mind manifesting," as a term for LSD and related hallucinogens, superseding the previously held "psychotomimetic" model (in which LSD was believed to mimic schizophrenia). In contrast to schizophrenia, LSD can induce transcendent experiences, with lasting psychological benefit.
Leslie Hicks is an American full professor of analytical chemistry at the University of North Carolina at Chapel Hill. Her work primarily focuses on the study of proteomics and protein post-translational modifications using mass spectrometry, and identifying biologically active peptides in plants.
In March 2020, UPS expanded its autonomous trips with TuSimple by adding an extra route between Phoenix and El Paso, Texas. In January 2021, UPS announced it had agreed to sell UPS Freight, its less-than-truckload freight business, to TFI International, a Canadian transport and logistics company, for $800 million. UPS said the move would allow it to focus on small-package delivery. At the time of the sale, UPS Freight had about 14,500 employees, approximately 11,000 of them represented by the Teamsters union, and generated an estimated $3.15 billion in revenue in 2020 offering services across the US, Canada, and Mexico. TFI had reported $4.1 billion in revenue in 2019 and already operated truckload and LTL services in Canada. The acquisition was completed in April and UPS Freight was renamed TForce Freight. In 2021, following the company's shift to target smaller customers to boost profits during the COVID-19 pandemic, UPS reported a 21% jump in their fourth quarter sales to $24.9 billion. CEO Carol Tomé reported that Amazon paid UPS $11.3 billion in shipping in 2020, accounting for 13.3% of the company's revenue. In September 2021, UPS entered into an agreement to acquire Roadie for an undisclosed amount with the transaction expected to be closed in the fourth quarter. In May 2022, UPS acquired logistics company Delivery Solutions, a key partner for Walmart's GoLocal network. In November 2022, it was announced UPS had acquired the healthcare focused, Europe-based warehousing and temperature-controlled transport company, Bomi Group.
From ancient times until the advent of the modern era, the most widely worn traditional dress in India was draped. For women, it took the form of a sari, a single piece of cloth many yards long. The sari was traditionally wrapped around the lower body and the shoulder. In its modern form, it is combined with an underskirt, or Indian petticoat, and tucked in along the waistband for more secure fastening. It is also commonly worn with an Indian blouse, or choli, which serves as the primary upper-body garment; the sari's end passes over the shoulder, covering the midriff and obscuring the upper body's contours. For men, a similar but shorter length of cloth, the dhoti, has served as a lower-body garment. The use of stitched clothes became widespread after Muslim rule was established by the Delhi Sultanate (c. 1300 CE) and continued by the Mughal Empire (c. 1525 CE). Among the garments introduced during this time and still commonly worn are: the shalwars and pyjamas, both styles of trousers, and the tunics kurta and kameez. Shalwars are atypically wide at the waist but narrow to a cuffed bottom. A drawstring holds them up, causing them to pleat at the waist. When the pants are cut quite narrow, on the bias, they are called churidars. The kameez is a long shirt or tunic. Its side seams left open below the waistline. The kurta is traditionally collarless and made of cotton or silk; it is worn plain or with embroidered decoration, such as chikankari; and typically falls to either just above or just below the wearer's knees.
Sources: en.wikipedia.org
== Business and finance == CLS Group, a global financial market utility Celestica, New York Stock Exchange symbol CLS Communication, translation services CLS Holdings, UK investment company Core Labor Standards, ILO Crown Liquor Saloon, ornate bar in Belfast, Northern Ireland
One of the best examples of the special features caused by DNA encoding is the synthesis of the self-assembling library introduced by Mlecco et al. First, two sublibraries are synthesized. In one of the sublibraries BBs are attached to the 5’ end of an oligonucleotide containing a dimerization domain followed by the codes of the BBs. In the other sublibrary the BBs are attached to the 3’ end of the oligonucleotides also containing a dimerization domain and the codes of another set of BBs. The two sublibraries are mixed in equimolar quantities, heated to 70 °C then allowed to cool to room temperature, heterodimerize and form the self-assembling combinatorial library. One member of such two pharmacophore library is shown in the figure. In affinity screening, the two BBs of the pharmacophore may interact with the two adjacent binding sites of the target protein.
The right and left fibrous rings of heart (annuli fibrosi cordis) surround the atrioventricular and arterial orifices. The right fibrous ring is known as the annulus fibrosus dexter cordis, and the left is known as the annulus fibrosus sinister cordis. The right fibrous trigone is continuous with the central fibrous body. This is the strongest part of the fibrous cardiac skeleton. The upper chambers (atria) and lower (ventricles) are electrically divided by the properties of collagen proteins within the rings. The valve rings, central body, and skeleton of the heart consisting of collagen are impermeable to electrical propagation. The only channel allowed (barring accessory/rare preexcitation channels) through this collagen barrier is represented by a sinus that opens up to the atrioventricular node and exits to the bundle of His. The muscle origins/insertions of many of the cardiomyocytes are anchored to opposite sides of the valve rings. The atrioventricular rings serve for the attachment of the muscular fibers of the atria and ventricles, and for the attachment of the bicuspid and tricuspid valves. The left atrioventricular ring is closely connected, by its right margin, with the aortic arterial ring; between these and the right atrioventricular ring is a triangular mass of fibrous tissue, the fibrous trigone, which represents the os cordis seen in the heart of some of the larger animals, such as the ox. Lastly, there is the tendinous band, already referred to, the posterior surface of the conus arteriosus.
A styptic (also spelled stiptic) is a specific type of antihemorrhagic agent that works by contracting tissue to seal injured blood vessels. Styptic pencils contain astringents. A common delivery system for this is a styptic or hemostatic pencil (not to be confused with a caustic pencil). This is a short stick of medication. Anhydrous aluminium sulfate is the main ingredient and acts as a vasoconstrictor in order to disable blood flow. The stick is applied directly to the bleeding site. The high ionic strength promotes flocculation of the blood, and the astringent chemical causes local vasoconstriction. Before safety razors were invented, a styptic pencil was a standard part of a shaving kit and was used to seal shaving cuts. Some people continue to use styptic pencils for minor skin wounds from safety or electric razors. Styptic powder is used in the veterinary trade to stop bleeding from nails that are clipped too closely. This powder is generally used on animals, such as cats, dogs, and rabbits, whose vein is found in the center of the nail.
Sources: en.wikipedia.org
Peukert ended his essay stating that there were debates about "our dealings with others, notably those different from ourselves. Recent debates about foreign migrants and AIDs present a conflicting picture. On one hand, we can see the continuing survival of a discourse on segregation, untouched by any historical self-consciousness. On the other hand, however, there is a considerable body of opinion pledging for tolerance and responsibility that spring from an awareness of German history and of the genesis of the "Final Solution" from the spirit of science".
==== 1935–1949 ==== Teva Pharmaceutical Industries took its present form through the efforts of Günther Friedländer and his aunt Else Kober on May 1, 1935. The original registration was under the name Teva Middle East Pharmaceutical & Chemical Works Co. Ltd. in Jerusalem, then part of Mandatory Palestine. Friedländer was a German pharmacist, botanist and pharmacognosist, who immigrated to Mandatory Palestine in 1934. The company was built with an investment of £4,900, which came from the family's own capital and partly from loans from other German immigrants. Capital shortage led to the joining of the banker Alfred Feuchtwanger as a partner in Teva, who received 33% of the shares in return for his investment. Friedländer's business philosophy opined that the pharmaceutical industry has a reliable basis in difficult economic times, since "A Jewish mother will always buy medicine for her children". In the Second World War, the company provided medicine to the allied forces and in particular to the British army present in the Middle East. After the war, Sir Alan Gordon Cunningham, the last of the High Commissioners for Palestine and Transjordan, visited Teva on behalf of the Secretary of State for the Colonies. His visit promoted Teva's reputation in the pharmaceutical market and created a momentum for Teva's development. During Mandatory Palestine, Teva exported its medical products to Arab countries. In 1941, Friedländer presented Teva products in an exhibition held in Cairo, Egypt.
== Dietary recommendations == The National Academy of Medicine updated the Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for riboflavin in 1998. The EARs for riboflavin for women and men aged 14 and over are 0.9 mg/day and 1.1 mg/day, respectively; the RDAs are 1.1 and 1.3 mg/day, respectively. RDAs are higher than EARs to provide adequate intake levels for individuals with higher than average requirements. The RDA during pregnancy is 1.4 mg/day and the RDA for lactating females is 1.6 mg/day. For infants up to the age of 12 months, the Adequate Intake (AI) is 0.3–0.4 mg/day and for children aged 1–13 years the RDA increases with age from 0.5 to 0.9 mg/day. As for safety, the IOM sets tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of riboflavin there is no UL, as there is no human data for adverse effects from high doses. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes (DRIs). The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL are defined the same as in United States. For women and men aged 15 and older the PRI is set at 1.6 mg/day. The PRI during pregnancy is 1.9 mg/day and the PRI for lactating females is 2.0 mg/day. For children aged 1–14 years the PRIs increase with age from 0.6 to 1.4 mg/day. These PRIs are higher than the US RDAs.
Sources: en.wikipedia.org
It is a tripeptide of glutamic acid, cysteine, and glycine. The linkage between glutamate and cysteine uses the gamma-carboxyl group, which is unusual for peptides.
GSH is the reduced form with a free thiol group. GSSG is the oxidized dimer formed when two GSH molecules join by a disulfide bond.
It is synthesized inside cells and is not classified as an essential dietary nutrient for most people. Dietary and supplemental sources are studied, but direct requirements are not established in the same way as for vitamins.
Glutathione is a sulfur-containing tripeptide made from glutamate, cysteine, and glycine. It is found in most cells and participates in redox balance and detoxification reactions.