Everything below concerns GSH. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-03-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Biosynthesis proceeds in two ATP-dependent steps. First, glutamate-cysteine ligase joins glutamate and cysteine. Second, glutathione synthetase adds glycine to the intermediate. The pathway is regulated by cysteine availability, enzyme expression, and feedback inhibition by glutathione itself. Liver tissue has a particularly high capacity for synthesis and export. Because the molecule is made inside cells, circulating glutathione reflects a balance of release, uptake, and breakdown rather than simple dietary supply.
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.
| Property | Value | Notes |
|---|---|---|
| Common name | Glutathione (reduced form) | Often abbreviated GSH |
| Chemical class | Tripeptide | Contains glutamate, cysteine, and glycine |
| Molecular formula | C10H17N3O6S | Refers to the reduced form |
| Molar mass | 307.32 g/mol | Calculated for C10H17N3O6S |
| Appearance | White to off-white powder | Typical laboratory-grade solid |
== External links == IUPAC, Compendium of Chemical Terminology, 5th ed. (the "Gold Book") (2025). Online version: (2006–) "nitrile". doi:10.1351/goldbook.N04151 IUPAC, Compendium of Chemical Terminology, 5th ed. (the "Gold Book") (2025). Online version: (2006–) "cyanide". doi:10.1351/goldbook.C01486
The metabolism of drugs is mainly by metabolic enzyme cytochrome P450, and this enzyme is not active in skin. The CYP450 actively metabolized drugs can then maintain high concentration when being applied on skin. Despite CYP450 enzyme action, the partition coefficient (K) determines the activity of topical drugs. The ability of drug particles to go through the skin layer also affects the absorption of drugs. For transdermal activity, medicines with higher K value are harder to get rid of the lipid layer of skin cells. The trapped molecules then cannot penetrate into the skin. This reduces the efficacy of the transdermal drugs. The drugs target cells underneath the skin or need to diffuse into blood capillary to exert their effect. Meanwhile, the size of particles affects this transdermal process. The smaller the drug molecules, the faster the rate of penetration. Polarity of the drugs can affect this diffusion rate too. If the drug shows lower degree of ionization, it is less polar. Therefore, it can have a faster absorption rate.
Laboratory stewardship is an approach to improving the appropriate use of clinical laboratory services, including the ordering, retrieval, and interpretation of laboratory tests. It seeks to improve the value of laboratory services by balancing the quality and clinical utility of testing against its costs, rather than simply reducing the number of tests performed. Laboratory stewardship may address both overuse and underuse of laboratory testing, with the aim of reducing low-value testing while increasing the use of clinically appropriate testing. Inappropriate laboratory testing can contribute to diagnostic errors, unnecessary phlebotomy, false positive results, delays in appropriate testing, and cascades of additional investigations, and waste of healthcare resources, while underuse can delay diagnosis and treatment. Studies have estimated that approximately 10–30% of laboratory tests may be unnecessary or inappropriate. Routine blood collection can also cause discomfort and sleep disruption, and repeated phlebotomy can contribute substantially to blood loss in some hospitalized patients. Errors in ordering, retrieving, or interpreting laboratory tests can contribute to delayed or incorrect diagnoses, inappropriate treatment, and other adverse outcomes. Laboratory stewardship therefore forms part of quality improvement and patient safety efforts in laboratory medicine.
Sources: en.wikipedia.org
=== Viruses === Brine pockets can support a wide variety of bacteria, and they are also home to high concentrations of marine viruses. Marine viruses in brine pockets may play a major role in regulating the population dynamics of their hosts and influencing biogeochemical cycles within the pocket. As viruses are highly specific to their hosts, viruses in brine pockets include bacteriophages, which infect bacteria, and archaeal viruses, which infect archaea. Algal viruses and other eukaryotic viruses can also be present in brine pockets, which influences the productivity and diversity of these microorganisms. Marine viruses in brine pockets can also influence biogeochemical processes by releasing nutrients through the lysis of infected cells, and by facilitating horizontal gene transfer between hosts. Infections caused by viruses can also trigger changes in the host metabolism, leading to altered nutrient uptake and production of metabolites, which in turn can influence the surrounding environment. The few studies on viral abundance and composition in brine pockets focus mainly on the diverse concentrations of viruses, separated by molecular size. Brine pockets in the Antarctic lakes have been found to have three groups of viruses at different abundances. In the Arctic waters, viral concentrations were found to vary from 1.6 to 82 × 106 ml−1, with the highest concentrations found in the coldest brine pockets (–24 to –31 °C).
=== Supercritical desalination === The solubility of dissolved ions drops precipitously once a fluid becomes supercritical. This effect can be used to precipitate salts from high salinity desalination streams, with solubility of different salts decreasing rapidly as water approaches supercritical temperatures. Complex cycle design can enable selective precipitation and improved heat recovery. Some very saline water sources like produced water also have high hydrocarbon content, which can be oxidized by supercritical desalination.
Bulb shape and size designations are given in national standards. Some designations are one or more letters followed by one or more numbers, e.g. A55 or PAR38, where the letters identify the shape and the numbers some characteristic size. National standards such as ANSI C79.1-2002, IS 14897:2000 and JIS C 7710:1988 cover a common terminology for bulb shapes.
Sources: en.wikipedia.org
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.
No. It is a tripeptide assembled from three amino acids. The term amino acid applies to the individual building blocks, not to the assembled molecule.
It is present in many tissues, with especially high amounts in liver. Intracellular concentrations are generally much higher than those found in blood plasma.
It is a tripeptide of glutamate, cysteine, and glycine. The glutamate-cysteine bond is unusual because it forms through the gamma-carboxyl group.