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.
Updated 2026-05-01. Numbers and descriptions here follow the published literature rather than marketing material.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine. It occurs in nearly all living cells, with highest concentrations in liver, kidney, and red blood cells, and exists in reduced (GSH) and oxidized disulfide (GSSG) forms. The cysteine thiol group enables reversible oxidation and reduction reactions. This property makes glutathione a central participant in cellular redox balance. The balance between these forms is often used as an indicator of oxidative stress.
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.
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 present in most tissues, with especially high concentrations in the liver. It also serves as a cofactor for some enzymes and helps transport amino acids across cell membranes. In plants and microorganisms, glutathione contributes to stress responses and metal handling. The molecule is synthesized in two ATP-dependent steps, first producing gamma-glutamylcysteine and then adding glycine. Because cysteine availability often limits synthesis, dietary and metabolic factors can influence glutathione levels. Research continues to examine how these levels relate to health and disease.
| Property | Value | Notes |
|---|---|---|
| Common name | Glutathione | Reduced form is abbreviated GSH |
| Chemical class | Tripeptide | Composed of glutamate, cysteine, and glycine |
| Molar mass | 307.32 g/mol | For reduced glutathione |
| CAS Registry Number | 70-18-8 | For reduced L-glutathione |
| Appearance | White crystalline powder | Typical solid reference material |
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.
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.
Because GSH is central to redox balance, its status is studied in aging, liver disease, neurodegenerative conditions, and metabolic disorders. Observational studies often report lower GSH or higher GSSG in affected tissues, but such associations do not establish that raising glutathione changes disease outcomes. Oral glutathione is digested into amino acids, and whether intact absorption occurs remains debated; precursors such as N-acetylcysteine and cysteine donors are also investigated. Regulatory agencies generally treat glutathione as a dietary supplement, not an approved drug, and clinical claims require evidence from controlled trials.
Glutathione is a small tripeptide composed of glutamate, cysteine, and glycine, with the unusual gamma-glutamyl linkage between glutamate and cysteine. Its cysteine thiol group makes it a major non-enzymatic antioxidant in cells. The reduced form, GSH, predominates in most intracellular compartments, while the oxidized disulfide form, GSSG, is produced when GSH reduces reactive oxygen species. Intracellular concentrations often reach millimolar levels, whereas plasma concentrations are much lower, typically in the low micromolar range. This gradient reflects active synthesis, transport, and consumption rather than passive distribution.
Glutathione supports detoxification by conjugating reactive electrophiles through glutathione S-transferases. The resulting conjugates are processed and exported, often after further metabolism. It also stores cysteine, transports amino acids across membranes through the gamma-glutamyl cycle, and assists in the maturation of iron-sulfur clusters and some prostaglandins. In plants, animals, and many microbes, the molecule appears in similar roles, but concentrations vary enormously between tissues. Liver, kidney, and red blood cells tend to contain high amounts, while blood plasma contains much less.
Glutathione is a small tripeptide built from glutamate, cysteine, and glycine. The peptide bond between glutamate and cysteine uses the gamma-carboxyl group, a linkage that resists ordinary peptidases. Cells make it in two ATP-dependent steps: gamma-glutamylcysteine synthetase joins glutamate and cysteine, then glutathione synthetase adds glycine. The pathway is feedback-inhibited by glutathione itself, so intracellular levels tend to stay within a narrow range. Because cysteine is often limiting, sulfur amino acid supply influences how much glutathione a cell can produce.
In its reduced form, glutathione carries a sulfhydryl group that can donate electrons. This property lets it act as a major cellular antioxidant and redox buffer. Glutathione peroxidase uses it to reduce hydrogen peroxide and lipid peroxides, while glutathione reductase regenerates the reduced form using NADPH. The ratio of reduced glutathione to glutathione disulfide is widely used as an indicator of oxidative stress, though the ratio changes with compartment, cell type, and sample handling. Oxidized glutathione can also form mixed disulfides with proteins, affecting their activity.
=== Diaphragm check valve === A diaphragm check valve uses a flexing rubber diaphragm positioned to create a normally-closed valve. Pressure on the upstream side must be greater than the pressure on the downstream side by a certain amount, known as the pressure differential, for the check valve to open allowing flow. Once positive pressure stops, the diaphragm automatically flexes back to its original closed position. This type is used in respirators (face masks) with an exhalation valve.
== Function == Humanin has several cytoprotective effects. Humanin and related peptides have antiinflammatory, immunomodulatory and neuroprotective effects and are of interest in the treatment of cardiovascular diseases such as atherosclerosis and heart failure, and neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and Huntington's disease.
==== Formation of the UPP ==== The Unidade de Polícia Pacificadora (Pacifying Police Units) or UPP was a security program in Rio de Janeiro that aimed to reclaim favelas from criminal organizations, such as CV, ADA, and TCP, through community policing. The strategy worked in two parts: deployment of the Military Police of Rio (PMERJ) into the favelas, and then increasing the amount of police officers who were meant to interact with the community through units, in hopes of creating a healthier relationship between favela residents and law enforcement than what existed in years prior. For decades, interactions with police in Rio de Janeiro were abrasive; violent conflicts between drug traffickers and the police led to widespread civilian casualties, and numerous instances of abuses of power by the police led to a general distrust by favela residents. The creation of the UPP aimed to both restructure the police force and its interactions with civilians, while also deterring criminal activity leading up to the 2014 World Cup and 2016 Summer Olympics. A secondary component of the UPP plan was the creation of UPP Social, which aimed to address the social welfare needs of the favelas by UPP units. This included improvements to sanitation, education, and healthcare, among other social issues. In 2008, the first UPP was set up in the Santa Marta favela, with more quickly following -- coalescing in 32 units overall, spanning all of Rio de Janeiro's zones (though most were located in Zona Norte).
Gramicidin S differs from other gramicidin types in that it is a cationic cyclic decapeptide and has a structure of an anti-parallel beta-sheet. Gramicidin S molecule is amphiphilic, with hydrophobic amino acids (D-Phe, Val, Leu side chains) and charged aminoacid (L-Orn). It exhibits strong antibiotic activity towards Gram-negative and Gram-positive and even several pathogenic fungi. The mode of action is not entirely agreed upon, but it is generally accepted that it is disruption of the lipid membrane and enhancement of the permeability of the bacterial cytoplasmic membrane. Unfortunately, being hemolytic at even low concentrations, gramicidin S is only used as topical applications at present. Additionally, Gramicidin S has been employed as a spermicide and therapeutic for genital ulcers caused by sexually transmitted disease.
Sources: en.wikipedia.org
=== Economics === In June 2020, Gilead announced that it had set the price of remdesivir at US$390 per vial for the governments of developed countries, including the United States, and US$520 for US private health insurance companies. The expected course of treatment is six vials over five days for a total cost of US$2,340. Being a repurposed drug, the minimum production cost for remdesivir is estimated at US$0.93 per day of treatment. In July 2020, the European Union secured a €63 million (US$74 million) contract with Gilead, to make the drug available there in early August 2020. In October 2020, Gilead Sciences and the European Commission announced they had signed a joint procurement framework contract in which Gilead agreed to provide up to 500,000 remdesivir treatment courses over the next six months to 37 European countries. Among the contracting countries were all 27 EU member states plus the United Kingdom, "Albania, Bosnia & Herzegovina, Iceland, Kosovo, Montenegro, North Macedonia, Norway, and Serbia". At the time, the price per treatment course was not disclosed; Reuters reported the price was 2,070 euros, thereby implying the total value of the contract (if all 500,000 courses are ordered) is approximately €1.035 billion. Under the contract, each participating country will directly place orders with Gilead and pay Gilead directly for its own orders.
Factors affecting chain length and pattern distribution α-Keto acid primers are used to produce branched-chain fatty acids that, in general, are between 12 and 17 carbons in length. The proportions of these branched-chain fatty acids tend to be uniform and consistent among a particular bacterial species but may be altered due to changes in malonyl-CoA concentration, temperature, or heat-stable factors (HSF) present. All of these factors may affect chain length, and HSFs have been demonstrated to alter the specificity of BCKA decarboxylase for a particular α-keto acid substrate, thus shifting the ratio of branched-chain fatty acids produced. An increase in malonyl-CoA concentration has been shown to result in a larger proportion of C17 fatty acids produced, up until the optimal concentration (≈20μM) of malonyl-CoA is reached. Decreased temperatures also tend to shift the fatty-acid distribution slightly toward C17 fatty-acids in Bacillus species.
government experiment that infected hundreds of Guatemalans with syphilis". A previous suit against the United States government was dismissed in 2011 for the Guatemala syphilis experiments when a judge determined that the U.S. government could not be held liable for actions committed outside of the U.S. An experiment was conducted by Vanderbilt University in the 1940s where they gave 800 pregnant women radioactive iron, 751 of which were pills, without their consent. In a 1969 article published in the American Journal of Epidemiology, it was estimated that three children had died from the experiment.
mitochondrial DNA (mtDNA) The set of DNA molecules contained within mitochondria, usually one or more circular plasmids representing a semi-autonomous genome which is physically separate from and functionally independent of the chromosomal DNA in the cell's nucleus. The mitochondrial genome encodes many unique enzymes found only in mitochondria.
The city of Sibiu, with its Brukenthal National Museum, was selected as the 2007 European Capital of Culture and the 2019 European Region of Gastronomy. Multiple castles exist in Romania, including the popular tourist attractions of Peleș Castle, Corvin Castle, and Bran Castle or "Dracula's Castle".
Sources: en.wikipedia.org
GSH is the reduced thiol form, while GSSG is the disulfide-linked oxidized dimer. The GSH:GSSG ratio is used as a redox indicator, though the ratio can vary with sample handling and cell type.
Glutathione is present in many foods, including meats, poultry, fish, some vegetables, and fruits. Cooking, storage, and digestion affect the amounts available for absorption.
Yes, both enzymatic steps in glutathione synthesis consume ATP. The first step, catalyzed by glutamate-cysteine ligase, is usually rate-limiting.
Glutathione is a tripeptide made from glutamate, cysteine, and glycine. Its cysteine residue provides a thiol group that is central to its redox activity. The glutamate-cysteine bond forms through the gamma-carboxyl group of glutamate.