thiol is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 | Tripeptide of glutamate, cysteine, and glycine. |
| Molar mass | 307.32 g/mol | Calculated from the molecular formula. |
| Appearance | White to off-white powder | Typically crystalline or lyophilized solid. |
| Solubility | Soluble in water; insoluble in ethanol | Aqueous solutions are acidic and prone to oxidation. |
| Typical storage | -20 °C, desiccated, protect from light | Reduce exposure to oxygen and moisture. |
In cells, glutathione helps maintain the reducing environment of the cytosol and supports enzymes that counteract reactive oxygen species. It acts as a cofactor for glutathione peroxidases, which reduce hydrogen peroxide and lipid peroxides, and for glutathione S-transferases, which conjugate electrophiles. The ratio of GSH to GSSG is often used as an indicator of oxidative stress, although the ratio can vary by compartment and cell type. Glutathione also stores cysteine, an amino acid that can be limiting for protein synthesis and antioxidant defense.
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 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.
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.
Several analytical methods can quantify glutathione, including high-performance liquid chromatography (HPLC) with UV or fluorescence detection for separating GSH and GSSG. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers higher specificity and sensitivity, often detecting nanomolar concentrations. The enzymatic recycling assay, often called the Tietze method, measures total glutathione by coupling reduction of GSSG to a colorimetric or fluorometric readout. Capillary electrophoresis and electrochemical detection are also used in specialized laboratories. Each method has distinct advantages and limitations regarding throughput, cost, and susceptibility to interference.
Interpreting glutathione measurements requires attention to pre-analytical variables. The GSSG concentration in a sample can rise artificially during storage or processing, making the GSH/GSSG ratio unreliable if not controlled. Reference ranges vary by specimen type, assay, and population, so comparisons across studies are difficult. Plasma glutathione is low and sensitive to hemolysis, while whole blood reflects primarily erythrocyte content. Many studies measure total glutathione rather than the reduced and oxidized forms separately, which limits conclusions about redox status.
An evaporative light scattering detector (ELSD) is a destructive chromatography detector, used in conjunction with high-performance liquid chromatography (HPLC), ultra high-performance liquid chromatography (UHPLC), purification liquid chromatography such as flash or preparative chromatography (using a splitter), countercurrent or centrifugal partition chromatography and supercritical fluid chromatography (SFC). It is commonly used for analysis of compounds that do not absorb UV-VIS radiation significantly, such as sugars, antiviral drugs, antibiotics, fatty acids, lipids, oils, phospholipids, polymers, surfactants, terpenoids and triglycerides. ELSDs works by nebulizing the column's effluents into a fine aerosol mist, which then passes through a heated drift tube, where the solvent evaporates. Thus, it can be easily used in gradient method of LC and SFC. The remaining non-volatile analyte particles are carried further by a carrier gas to a light scattering cell, where a beam of light illuminates them and they scatter it. The scattered light proceeds to a photodiode which converts it to a signal, which is proportional to the mass of the analyte particles. This is why it is considered as a sort of "universal detector" as it is able to detect all compound which are less volatile than the mobile phase, i.e. non volatile and semi-volatile compounds. ELSD is related to the charged aerosol detector (CAD), in which the aerosol is charged. Like the CAD, it falls under the category of destructive detectors.
On January 8, 1850, a U.S. post office was established in Albany, with John Burkhart appointed as the first U.S. Postmaster. The town was renamed as "New Albany" on November 4, 1850, but the name was changed back to Albany in 1853. In 1851, Albany was designated as the county seat, replacing Calapooia (near modern-day Brownsville and Sweet Home), and all court meetings were held there. The first Albany courthouse was built in 1852 on 10 acres (4.0 ha) of land donated by the Monteiths to ensure Albany would remain the county seat. The new two-story octagonal courthouse was completed on April 26, 1853. The courthouse has since been replaced, but the new courthouse stands on the same site. During 1853–1854, residents of the east side of Albany persuaded the Oregon Legislative Assembly to name both towns Takenah. Though Takenah meant "deep pool," in reference to the confluence of the Calapooia and Willamette rivers, it was commonly translated as "Hole in the Ground". Partially due to this translation, the legislature restored the name Albany to the town in 1855. Finally in 1864, 16 years after the Monteiths founded the town and 19 years after the first European Americans arrived, it became incorporated as a city.
Alan Dershowitz, Claus's attorney, wrote a book about the case, Reversal of Fortune: Inside the von Bülow Case (New York, Random House 1986 and London, Penguin Books 1991). The 1990 film Reversal of Fortune was based on Dershowitz's books about the case, with Glenn Close playing Sunny and Jeremy Irons playing Claus von Bülow, a performance for which he was awarded an Academy Award for Best Actor. Bill Kurtis narrated an episode of the series American Justice titled "Von Bulow: A Wealth of Evidence". The American television series Biography produced and aired a documentary episode titled "Claus von Bülow: A Reasonable Doubt", with interviews of Claus Von Bülow and Alan Dershowitz. The case is referenced in the Seinfeld episode "The Suicide". Jerry Seinfeld is in a hospital room watching over a comatose neighbor. To the neighbor's ex-girlfriend he remarked, "It's not like a Sunny Von Bülow coma. Doctor said he should snap out of it anytime." Sunny is referenced in the American television show Will & Grace, in which socialite Karen Walker asks more than once about Sunny being “out of bed.”
== Levels == hPL is present only during pregnancy, with maternal serum levels rising in relation to the growth of the fetus and placenta. Maximum levels are reached near term, typically to 5–7 mg/L. Higher levels are noted in patients with multiple gestation. Little hPL enters the fetal circulation. Its biological half-life is 15 minutes. Some women with higher BMI show lower levels of placental lactogen, but whether prenatal health behaviors influence hPL levels or if hPL influences infant birth weight is uncertain.
==== Others ==== Flutamide has also been associated with interstitial pneumonitis (which can progress to pulmonary fibrosis). The incidence of interstitial pneumonitis with flutamide was found to be 0.04% (4 per 10,000) in a large clinical cohort of 41,700 prostate cancer patients. A variety of case reports have associated flutamide with photosensitivity. Flutamide has been associated with several case reports of methemoglobinemia. Bicalutamide does not appear to share this risk with flutamide. Flutamide has also been associated with reports of sulfhemoglobinemia and neutropenia.
Sources: en.wikipedia.org
=== Hart House === In August 2022, Hart debuted a vegan restaurant, Hart House, to compete with fast-food chains by "offering flavorful plant-based alternatives". The restaurant opened in Los Angeles, California, about a mile from Los Angeles International Airport (LAX), with a simple menu of veggie burgers and Chick'n products. The restaurant's offerings are claimed to be "entirely free of cholesterol, antibiotics, hormones, artificial colors, preservatives, high-fructose corn syrup, or trans fats", and inspired by Hart's own "health nut" lifestyle. Hart opened a second location in Monrovia, California, in November 2022, a third on Sunset Boulevard in Hollywood, California, in May 2023, and a fourth location near the University of Southern California campus in June 2023. All locations closed in September 2024.
This article was submitted to WikiJournal of Medicine for external academic peer review in 2021 (reviewer reports). The updated content was reintegrated into the Wikipedia page under a CC-BY-SA-3.0 license (2021). The version of record as reviewed is: Kholhring Lalchhandama; et al. (2021). "History of penicillin" (PDF). WikiJournal of Medicine. 8 (1): 3. doi:10.15347/wjm/2021.003. Wikidata Q107303937.
Polyendocrine metabolic ovarian syndrome (PMOS), previously called polycystic ovary syndrome (PCOS), is the most common hormonal disorder in women of reproductive age. PMOS is diagnosed when a woman has at least two of the following three features: irregular menstrual periods, high testosterone or related symptoms (like excess facial hair), or an excess of antral ovarian follicles on ultrasound. Persons with PMOS are not more likely than those without to have true ovarian cysts. A blood test for high levels of anti-Müllerian hormone can replace the ultrasound in the diagnosis. Other symptoms associated with PMOS are heavy periods, acne, difficulty getting pregnant, and patches of darker skin. The exact cause of PMOS remains uncertain. There is a clear genetic component, but environmental factors are also thought to contribute. PMOS occurs in between 5% and 18% of women. The disorder is linked to insulin resistance, which is made worse by obesity. Insulin resistance and related excess insulin levels increase the risk of complications such as type 2 diabetes and liver disease. Those living with PMOS also have higher risk of endometrial cancer.
== Reference ranges == General guidelines for diagnosing prolactin excess (hyperprolactinemia) define the upper threshold of normal prolactin at 25 μg/L for women and 20 μg/L for men. Similarly, guidelines for diagnosing prolactin deficiency (hypoprolactinemia) are defined as prolactin levels below 3 μg/L in women and 5 μg/L in men. However, different assays and methods for measuring prolactin are employed by different laboratories and as such the serum reference range for prolactin is often determined by the laboratory performing the measurement. Furthermore, prolactin levels vary according to factors as age, sex, menstrual cycle stage and pregnancy. The circumstances surrounding a given prolactin measurement (assay, patient condition, etc.) must therefore be considered before the measurement can be accurately interpreted. The following chart illustrates the variations seen in normal prolactin measurements across different populations. Prolactin values were obtained from specific control groups of varying sizes using the IMMULITE assay.
Sources: en.wikipedia.org
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.
No. It is a tripeptide made from three amino acids: glutamate, cysteine, and glycine. The gamma-glutamyl bond is unusual and distinguishes it from typical peptide linkages.
Most ingested glutathione is broken down in the gastrointestinal tract into its constituent amino acids. Some formulations may protect it from digestion, but intact absorption and delivery to specific tissues remain uncertain. Research continues on precursors and delivery methods.
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.