The short version of GSSG fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-22 and is reviewed periodically as new material appears.
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.
Several techniques are used for quantification. Enzymatic recycling assays rely on glutathione reductase and a colorimetric or fluorescent readout, offering sensitivity for total glutathione. High-performance liquid chromatography can separate GSH from GSSG and other thiols, often with UV, fluorescence, or electrochemical detection. Mass spectrometry provides structural confirmation and can quantify low-abundance species when paired with separation. Each approach has trade-offs in specificity, throughput, and equipment requirements, so method selection depends on the research question and available instrumentation.
Stability depends on pH, temperature, oxygen exposure, and trace metals. Aqueous solutions of reduced glutathione are susceptible to oxidation, especially when neutral or alkaline and exposed to air. Transition metal ions can catalyze thiol oxidation, so chelators and inert atmospheres are sometimes used in research settings. Standards are typically stored cold and desiccated, with limited freeze-thaw cycles. Questions remain about how closely in vitro stability data reflect the behavior of glutathione within intact cells and tissues.
| Property | Value | Notes |
|---|---|---|
| Chemical formula | C10H17N3O6S | Refers to the reduced form |
| Molar mass | 307.32 g/mol | Calculated for the neutral molecule |
| Appearance | White crystalline powder | Often hygroscopic; protect from moisture |
| Water solubility | Soluble in water | Reported values vary with purity and form |
| Alternative names | GSH, reduced glutathione | GSH specifies the thiol form |
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 serves as a cofactor for several enzymes, including glutathione peroxidase and glutathione S-transferase. These enzymes help reduce hydrogen peroxide and lipid peroxides, and they conjugate reactive electrophiles for excretion. The molecule also acts as a reservoir for cysteine, an amino acid that is prone to oxidation. In addition, glutathione participates in the metabolism of nitric oxide, leukotrienes, and prostaglandins. Its roles extend to cell signaling, apoptosis, and the regulation of protein function through S-glutathionylation.
Glutathione is a tripeptide composed of glutamate, cysteine, and glycine, and it is the most abundant non-protein thiol in most living cells. The reduced form, GSH, carries a sulfhydryl group that can donate electrons, while the oxidized form, GSSG, forms when two GSH molecules link via a disulfide bond. The balance between these two forms helps define the cellular redox environment, and their ratio is often used as an indicator of oxidative stress. Because the sulfhydryl group is reactive, glutathione participates in many cellular processes, including detoxification and protein regulation.
==== Europe ==== In May 1963, Scheer and Maier-Borst were the first to introduce the use of 99mTc for medical applications. In 1968, Philips-Duphar (later Mallinckrodt, today Covidien) marketed the first technetium-99m generator produced in Europe and distributed from Petten, the Netherlands.
The first presidential debate was held on June 27, 2024, between Biden and Trump. Biden's performance was widely criticized, with commentators saying he frequently lost his train of thought and gave meandering answers. Several newspaper columnists declared Trump the winner, and polling indicated the majority of viewers believed Trump won. After the debate raised questions about his health and age, Biden faced calls to withdraw from the race, including from Democrats and the editorial boards of various major news outlets. Biden initially insisted that he would remain a candidate, but on July 21, he withdrew from the race, writing that this was "in the best interest of my party and the country". He immediately endorsed Harris to replace him as the party's presidential nominee. On August 6, 2024, Harris officially became the Democratic presidential nominee. This was the first time an eligible incumbent had withdrawn a bid for reelection since 1968. In the general election, Trump defeated Harris. The Senate went Republican for the first time since 2018. In a nationally televised speech after the election, Biden congratulated Trump and promised a "peaceful and orderly" transition of power. In a January 2025 interview, Biden claimed he could have defeated Trump had he not been persuaded to withdraw from the election, despite lagging behind Trump in polling. A YouGov poll conducted on November 6–7, 2024, found that if Biden had been the Democratic nominee, Trump would have won the popular vote by 49% to 42%. Trump won the popular vote over Harris by 49.8% to 48.3%.
==== Recurrent psychotic episodes ==== Placebo-controlled trials of both first- and second-generation antipsychotic drugs consistently demonstrate the superiority of active drugs over placebos in suppressing psychotic symptoms. A large meta-analysis of 38 trials of antipsychotic drugs in schizophrenia with acute psychotic episodes showed an effect size of about 0.5. There is little or no difference in efficacy among approved antipsychotic drugs, including both first- and second-generation agents. The efficacy of such drugs is suboptimal. Few patients achieve complete resolution of symptoms. Response rates, calculated using various cutoff values for symptom reduction, are low, and their interpretation is complicated by high placebo response rates and selective publication of clinical trial results.
Adrenomix®: In 2009, a second-generation mixture was created, adding to the glycerol trioleate (GTO) and trierucate glycerol (GTE), conjugated linoleic acid (CLA) a group of linoleic acid isomers capable of overcoming the blood-brain barrier. CLA, through the activation of peroxisome beta oxidation, increases the catabolism of pro-inflammatory molecules and ROS, acting as an anti-inflammatory and antioxidant. The use of CLA was initially considered in relation to the ability to inhibit fatty acid synthase together with a hypolipidic diet. A group of Italian researchers of the Bambino Gesù Pediatric Hospital in Rome , Associazione Biomedicina e Nutrizione from Milan and Cagliari, showed that the administration of Adrenomix (GTO, GTE and CLA), in addition to decreasing levels of VLCFA throughout the body, reduces neuro inflammation and improves somatosensory evoked potential, found unchanged or worsened with only administration of GTO and GTE. Aldixyl®: In 2016, based on studies developed in recent years in the field of adrenoleukodystrophy and adrenomyelouropathy, a mixture was developed that adds to GTO, GTE and CLA, a mixture of powerful antioxidants at high dosages containing alpha lipoic acid (ALA), reduced L- glutathione and Vitamin E (α- tocopherol).
Sources: en.wikipedia.org
In size, malonylation (three carbons) is bulkier than acetylation (two) but smaller than succinylation (four) and glutarylation (five). As a result, such acidic acyl modifications, as discussed for malonylation and succinylation, are expected to exert a greater impact than acetylation at the same lysine site. Each modification arises from the corresponding acyl-CoA derivative. Malonyl‑CoA is produced in cytosol and mitochondria by acetyl‑CoA carboxylase (ACC) and, in mitochondria, also by acyl-CoA synthetase family member 3 (ACSF3); succinyl‑CoA stems from the TCA cycle and amino acid catabolism; glutaryl‑CoA from amino acid catabolism; and methylmalonyl‑CoA from amino acid and odd‑chain fatty acid metabolism, which accumulates in vitamin B12 deficiency and methylmalonic acidemias. Malonyl‑CoA is far less reactive toward proteins than succinyl‑CoA or glutaryl‑CoA because, like acetyl‑CoA, its shorter carbon chain cannot support the intramolecular catalysis needed to form a reactive cyclic anhydride intermediate, which in turn enables modification over a broader pH range. Malonyl, succinyl, and glutaryl groups are removed by Sirtuin 5 (SIRT5), which shows little activity toward acetylation.
== Conferences == The Society holds an annual conference in late May or early June as well as topical conferences (at Asilomar State Beach in California and Sanibel Island, Florida) and a fall workshop, which is also focused on a single topic. Conferences on Mass Spectrometry and Allied Topics have been held yearly since 1953.
==== Iodine ==== Iodine used for water purification is commonly added to water as a solution, in crystallized form, or in tablets containing tetraglycine hydroperiodide that release 8 mg of iodine per tablet. The iodine kills many, but not all, of the most common pathogens present in natural fresh water sources. Carrying iodine for water purification is an imperfect but lightweight solution for those in need of field purification of drinking water. Kits are available in camping stores that include an iodine pill and a second pill (vitamin C or ascorbic acid) that will remove the iodine taste from the water after it has been disinfected. The addition of vitamin C, in the form of a pill or in flavored drink powders, precipitates much of the iodine out of the solution, so it should not be added until the iodine has had sufficient time to work. This time is 30 minutes in relatively clear, warm water, but is considerably longer if the water is turbid or cold. If the iodine has precipitated out of the solution, then the drinking water has less available iodine in the solution. Tetraglycine hydroperiodide maintains its effectiveness indefinitely before the container is opened; although some manufacturers suggest not using the tablets more than three months after the container has initially been opened, the shelf life is in fact very long provided that the container is resealed immediately after each time it is opened. Similarly to potassium iodide (KI), sufficient consumption of tetraglycine hydroperiodide tablets may protect the thyroid against uptake of radioactive iodine.
The Cameron Prize for Therapeutics of the University of Edinburgh is awarded by the College of Medicine and Veterinary Medicine to a person who has made any highly important and valuable addition to practical therapeutics in the previous five years. The prize, which may be awarded biennially, was founded in 1878 by Andrew Robertson Cameron of Richmond, New South Wales, with a sum of £2,000. The University's senatus academicus may require the prizewinner to deliver one or more lectures or to publish an account on the addition made to practical therapeutics. A list of recipients of the prize dates back to 1879.
== Investigation == Between March and June 2022, unusually high infant mortality rates occurred at a neonatal nursing unit in the Ramón Castillo Neonatal Hospital in Córdoba, Argentina. A series of investigations initially pointed to a hospital-acquired infection or malpractice. The provincial government then intervened at the Ramón Castillo Neonatal Hospital after these reports of healthy babies dying without cause. Prosecutor Raúl Garzón labelled the case as "enormously grave" but initially insisted that they could have been either cases of malpractice or hospital-acquired infections, and no accusations were made. Nonetheless, Garzón ordered a search warrant on the hospital and relieved twenty employees from their duties. Police and prosecutors began to suspect that there had been foul play when no more deaths occurred after the suspension of those twenty employees. On the same day that the hospital was searched, authorities suspended the head of the hospital. The investigation was prompted by a doctor who refused to sign the death certificates of two healthy babies who died on the same day in June 2022; allegedly the two last babies to die from an external cause (murder). As the search warrant was served, the prosecution asked for the exhumation of the remains of the deceased babies, whose autopsies showed abnormal levels of potassium, which medical investigators attributed to being deliberately injected into the babies, as said levels of potassium are not normally produced by the body.
Sources: en.wikipedia.org
It is a tripeptide of glutamate, cysteine, and glycine. The glutamate-cysteine bond is unusual because it forms through the gamma-carboxyl group.
It reflects the balance between oxidant exposure and antioxidant capacity. The ratio is not a direct clinical diagnosis and depends on the tissue and sample method.
No. It also participates in detoxification, amino acid transport, and protein modification. Its roles vary by cell type and compartment.
Common methods include enzymatic recycling assays, liquid chromatography, and mass spectrometry. Many protocols separate reduced glutathione from its oxidized disulfide form before detection.