A practical reference on glutathione: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-11-19 and is reviewed periodically as new material appears.
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.
Synthesis occurs in two ATP-dependent steps: glutamate-cysteine ligase joins glutamate and cysteine to form gamma-glutamylcysteine, and glutathione synthetase adds glycine to complete the tripeptide. The pathway is feedback-inhibited by GSH and limited by cysteine availability, so cysteine supply often constrains production. Once formed, GSH participates in redox buffering, xenobiotic conjugation, and protein glutathionylation. Glutathione peroxidase uses GSH to reduce hydrogen peroxide and lipid peroxides, yielding GSSG, while glutathione reductase regenerates GSH using NADPH. Glutathione S-transferases conjugate electrophiles to GSH, supporting detoxification and excretion.
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.
| 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 |
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.
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.
== Other research == In October 2021, Relief announced that its collaboration partner, Texas-based Acer Therapeutics, had successfully filed for a New Drug Application with US FDA for their drug ACER-001, for the treatment of Urea Cycle Disorders (UCDs) and Maple syrup urine disease. In September 2021, APR launched a chewable tablet for the treatment of Phenylketonuria, called PKU GOLIKE KRUNCH, in Germany and Italy. APR are also developing Nexodyn, a drug which aids in the management of hard-to-heal ulcers requiring long periods of treatment. Relief is actively developing RLF-100 for non-COVID-19 related acute and chronic lung diseases, such as Pulmonary sarcoidosis.
Many of the Germans who stayed in Czechoslovakia later emigrated to West Germany (more than 100,000). As the German population was transferred out of the country, the former Sudetenland was resettled mostly by Czechs but also by other nationalities of Czechoslovakia: Slovaks, Greeks (arriving in the wake of the Greek Civil War 1946–49), Carpathian Ruthenians, Romani people and Jews who had survived the Holocaust, and Hungarians (though the Hungarians were forced to do so and later returned home—see Hungarians in Slovakia: Population exchanges). Some areas, such as part of Czech Silesian-Moravian borderland, southwestern Bohemia (Šumava National Park), western and northern parts of Bohemia, remained depopulated for several strategic reasons (extensive mining and military interests) or are now protected national parks and landscapes. Moreover, before the establishment of the Iron Curtain in 1952 to 1955, the so-called "forbidden zone" was established by means of engineer equipment up to 2 km (1.2 mi) from the border in which no civilians could reside. A wider region, or "border zone", existed up to 12 km (7 miles) from the border in which no "disloyal" or "suspect" civilians could reside or work. Thus, the entire Aš-Bulge fell within the border zone, a status that remained until the Velvet Revolution in 1989.
=== Ba'athist rule (1963–2024) === Following the 1963 coup, the People's Assembly largely served as a rubber stamp for the ruling Ba'athists. Only parties affiliated with the National Progressive Front could participate in elections. The 2012 elections, held on 7 May, resulted in a new parliament that, for the first time in four decades, was nominally based on a multi-party system. The opposition was represented by the Popular Front for Change and Liberation, which won six seats. It later boycotted the 2016 elections as the government had not upheld its pledges to seek constitutional amendments and pursue political negotiations. In 2016, Hadiya Khalaf Abbas, whom had represented Deir ez-Zor since 2003, became the first woman elected to be the Speaker, whilst in 2017, Hammouda Sabbagh became the first Syriac Orthodox Christian to have held the post.
Abiogenesis – Life arising from non-living matter Brine pool – Accumulation of brine in a seafloor depression Endeavour Hydrothermal Vents – Group of Pacific Ocean hydrothermal vents Extremophiles – Organisms capable of living in extreme environmentsPages displaying short descriptions of redirect targets Hydrogen sulfide chemosynthesis - system of generating energy used in hydrothermal vents Lost City Hydrothermal Field Magic Mountain (British Columbia) – Hydrothermal vent field in the northeast Pacific 9° North – Region of hydrothermal vents on the East Pacific Rise in the Pacific Ocean Pito Seamount – Seamount in the Pacific Ocean north-northwest of Easter Island Submarine volcano – Underwater vents or fissures in the Earth's surface from which magma can erupt Volcanogenic massive sulfide ore deposit, also known as VMS deposit – Metal sulfide ore deposit Deep sea mining
Sources: en.wikipedia.org
In September 1981, shortly after Mahathir assumed office as prime minister, the country carried out the "Dawn Raid", a calculated operation orchestrated by Permodalan Nasional Berhad (PNB) to regain majority ownership of Guthrie, one of the largest British-owned plantation companies at the time. This move symbolized a broader effort under Mahathir's leadership to reduce foreign dominance over Malaysia's economy and reclaim control of national assets. A month after the Dawn Raid, Mahathir introduced the "Buy British Last" (BBL) policy, which lasted from October 1981 to March 1983. The reason for this policy was rooted in several grievances with Britain. Britain's decision to abolish tuition fee subsidies for Commonwealth students placed a heavy financial burden on Malaysia, which had to cover the increased costs for approximately 17,000 Malaysian students studying in the UK. Additionally, British media criticism of Malaysia's internal policies further strained relations. The BBL policy, which directed government ministries and agencies to deprioritize British goods and services, significantly affected Britain, causing estimated losses of between £15.5 million and £50 million in the early months. This eventually led to negotiations, culminating in Mahathir and British Prime Minister Margaret Thatcher meeting in 1983 to resolve the tensions and end the policy. Mahathir later recalled persuading Thatcher that raising tuition fees was a mistake, leading Thatcher to introduce scholarships for Malaysian students.
Francis Harry Compton Crick (8 June 1916 – 28 July 2004) was an English molecular biologist, biophysicist, and neuroscientist. He, James Watson, Rosalind Franklin, and Maurice Wilkins played crucial roles in deciphering the helical structure of the DNA molecule. Crick and Watson's paper in Nature in 1953 laid the groundwork for understanding DNA structure and functions. Together with Maurice Wilkins, they were jointly awarded the 1962 Nobel Prize in Physiology or Medicine "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material". Crick was an important theoretical molecular biologist and played a crucial role in research related to revealing the helical structure of DNA. He is widely known for the use of the term "central dogma" to summarise the idea that once information is transferred from nucleic acids (DNA or RNA) to proteins, it cannot flow back to nucleic acids. In other words, the final step in the flow of information from nucleic acids to proteins is irreversible. During the remainder of his career, Crick held the post of J.W. Kieckhefer Distinguished Research Professor at the Salk Institute for Biological Studies in La Jolla, California. His later research centred on theoretical neurobiology and attempts to advance the scientific study of human consciousness. Crick remained in this post until his death in 2004; "he was editing a manuscript on his death bed, a scientist until the bitter end" according to Christof Koch.
Estradiol cypionate is available in the United States. It was previously marketed in Spain and Italy, but was discontinued in these countries and is no longer available in Europe. Estradiol cypionate has mostly been used in the United States, similarly to testosterone cypionate, with both of these medications having been developed by Upjohn, an American pharmaceutical company. Besides the United States, estradiol cypionate has been marketed in France, Germany, Italy, Spain, and Japan, among other countries. Estradiol cypionate for human use is not available in Canada, although it is marketed in several veterinary formulations in this country. Estradiol cypionate is available in Taiwan in combination with testosterone cypionate. It is also available as a combined injectable contraceptive in combination with medroxyprogesterone acetate in at least 18 countries, mostly in Latin America and Southeast Asia. Estradiol cypionate/testosterone cypionate and estradiol cypionate/medroxyprogesterone acetate were both formerly marketed in the United States, but have been discontinued in this country.
As a practical matter, when platinum group metals are purified through dissolution in aqua regia, gold (commonly associated with PGMs) is precipitated by treatment with iron(II) chloride. Platinum in the filtrate, as hexachloroplatinate(IV), is converted to ammonium hexachloroplatinate by the addition of ammonium chloride. This ammonium salt is extremely insoluble, and it can be filtered off. Ignition (strong heating) converts it to platinum metal: 3 [NH4]2[PtCl6] → 3 Pt + 2 N2 + 2 [NH4]Cl + 16 HCl Unprecipitated hexachloroplatinate(IV) is reduced with elemental zinc, and a similar method is suitable for small scale recovery of platinum from laboratory residues. Aqua regia reacts with tin to form tin(IV) chloride, containing tin in its highest oxidation state: 4 HCl + 2 HNO3 + Sn → SnCl4 + NO2 + NO + 3 H2O Aqua regia can react with iron pyrite to form iron(III) chloride: FeS2 + 5 HNO3 + 3 HCl → FeCl3 + 2 H2SO4 + 5 NO + 2 H2O
Though extremely neutron-rich for such a light element, 48Ca is very stable because it is a doubly magic nucleus, with 20 protons and 28 neutrons arranged in closed shells. Its beta decay to 48Sc is very hindered by the gross mismatch of nuclear spin: 48Ca has zero nuclear spin, being even–even, while 48Sc has spin 6+, so the decay is forbidden by conservation of angular momentum. While two excited states of 48Sc are available for decay as well, they are also forbidden due to their high spins. As a result, when 48Ca does decay, it does so by double beta decay to 48Ti instead, being the lightest nuclide known to undergo double beta decay. 46Ca can also theoretically double-beta-decay to 46Ti, but this has never been observed. The most common isotope 40Ca is also doubly magic and could undergo double electron capture to 40Ar, but this has likewise never been observed. Calcium is the only element with two primordial doubly magic isotopes. The experimental lower limits for the half-lives of 40Ca and 46Ca are 5.9 × 1021 years and 2.8 × 1015 years respectively. Excluding 48Ca, the longest lived radioisotope of calcium is 41Ca. It decays by electron capture to stable 41K with a half-life of about 105 years. Its existence in the early Solar System as an extinct radionuclide has been inferred from excesses of 41K. Traces of 41Ca also still exist today, as it is a cosmogenic nuclide, continuously produced through neutron activation of natural 40Ca. Many other calcium radioisotopes are known, ranging from 35Ca to 60Ca.
Sources: en.wikipedia.org
Troglitazone is an antidiabetic and anti-inflammatory drug, and a member of the drug class of the thiazolidinediones. It was prescribed for people with diabetes mellitus type 2. It was patented in 1983 and approved for medical use in 1997. It was subsequently withdrawn.
James Sherr, head of Russia and Eurasia Programme at Chatham House, wrote in The Telegraph: "The current crisis demonstrates that the Cold War has not been replaced by common values between East and West, but by the revival of hard Realpolitik. [...] Mikhail Saakashvili, Georgia's President, might have been profoundly unwise to employ massive force against the pro-Russian separatists in South Ossetia last Thursday, but his lapses of judgement are not the point. The commanders of Russian forces and their political masters in the Kremlin hoped he would behave exactly as he did. [...] Ukraine has no territorial conflicts, but it has a potential territorial dispute, Crimea." On 10 August 2008, Quentin Peel wrote in the Financial Times, "Saakashvili boosted military spending and refused to rule out the use of force. But he did not intend to use it. By all accounts he was unprepared for the latest confrontation: he was booked to be on a flight to Beijing." On 11 August 2008, The New York Times noted Putin's strong personal enmity towards Georgian president Saakashvili. On 11 August 2008, Robert Kagan wrote that the war was not a result of a "miscalculation" by Georgia, but "revanchist" Russia's attempt to respond to revolutions in Georgia and Ukraine.
=== Pain scale === Acute or chronic pain can be directly measured by pain scales such as the numerical rating scale (NRS) and visual analog scale (VAS). A serial pain scale from 0 (no pain) to 10 (worst pain imaginable) can quantify pain intensity. It can also monitor symptom improvement in nursing women who experience persistent nipple pain for at least two weeks postpartum.
Historian John Lewis Gaddis claims that Solidarity survived repression because it embodied a distinctive national identity that communist authorities were unable to suppress, while economic stagnation increasingly discredited the ruling party's ideology. In February 1989 the Polish People's Republic opened talks with opposition, known as the Polish Round Table Agreement, which allowed elections with participation of anti-Communist parties in June 1989. These negotiations legalized Solidarity and established the framework for partially free parliamentary elections,which facilitated sweeping victory for opposition candidates and effectively ended communist rule in Poland. However, not every Communist regime showed the same restraint that year; a telling example stemmed from Chinese authorities, whose forces shot down hundreds of peaceful demonstrators in Tiananmen Square. Events in China provided a distinctive contrast, if not a vivid and grim demonstration of what the alternative looked like, to the conscious rejection of violence that shaped the East European revolutions.
Liquid water is present on Earth, covering 71% of its surface. Liquid water is also occasionally present in small amounts on Mars. Scientists believe liquid water is present in the Saturnian moons of Enceladus, as a 10-kilometre thick ocean approximately 30–40 kilometers below Enceladus' south polar surface, and Titan, as a subsurface layer, possibly mixed with ammonia. Jupiter's moon Europa has surface characteristics which suggest a subsurface liquid water ocean. Liquid water may also exist on Jupiter's moon Ganymede as a layer sandwiched between high pressure ice and rock.
Sources: en.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.
GSH is the reduced, thiol-containing form of glutathione, while GSSG is the oxidized disulfide dimer formed when two GSH molecules react. Cells maintain a high GSH-to-GSSG ratio under normal conditions. A shift toward GSSG is often interpreted as oxidative stress, though sample handling can affect the measured ratio.