Artemis Labs supplies glutathione as a 1500 mg vial of reduced glutathione (GSH) free acid — white to off-white crystalline powder, also supplied lyophilised — to a purity specification of ≥98% (HPLC), the typical research-grade specification. That figure is a specification, not a measured lot result; lot values are established by HPLC on the accompanying Certificate of Analysis, against the USP Glutathione monograph limit of NLT 98.0% / NMT 101.0% on the dried basis. Supplied as an analytical and biochemical research reagent for in vitro, cell-culture, and IACUC-approved animal workflows, under the Research Use Agreement and State Shipping Restrictions. Not a dietary supplement, drug, or cosmetic; no human-use, dosing, administration, or reconstitution protocols are provided or supported.
Glutathione is a peptide, though not the kind most of this catalogue contains: a tripeptide, γ-Glu-Cys-Gly, assembled non-ribosomally by two ATP-dependent enzymes rather than translated from mRNA. Glutamate cysteine ligase (GCL) joins glutamate to cysteine and glutathione synthetase adds glycine; GCL is rate-limiting and feedback-inhibited by glutathione itself, leaving cysteine availability and GCL expression as the only levers over pool size (Meister, 1983, PMID 6137189; Lu, 2013, PMID 22995213). Its defining feature is the γ-glutamyl isopeptide linkage: the Glu–Cys bond runs from glutamate’s side-chain (C5) carboxyl to cysteine’s α-amino group, not from the α-carboxyl, so this is no conventional α-linked peptide and ordinary peptidases cannot cleave it. It is accordingly not a signalling peptide but a millimolar-concentration intracellular redox buffer — the dominant low-molecular-weight thiol — cycling between GSH and the disulfide GSSG as glutathione peroxidases reduce hydroperoxides at the cost of two GSH (Pei et al., 2023, PMID 36937839). Form disambiguation matters: this is reduced GSH free acid, CAS 70-18-8, C₁₀H₁₇N₃O₆S, MW 307.33 — not oxidised GSSG (CAS 27025-41-8, MW 612.6), not the sodium salt (CAS 34212-83-4, MW 329.31). GSSG appears here solely as an impurity specification (≤1.5%) — the rationale for the desiccated, light-protected cold-storage condition — never as an alternative description of the vial’s contents.
For mechanism context, internal-link investigators to the pyridine-nucleotide and mitochondrial arms of this network: NAD+, because glutathione reductase regenerates GSSG to GSH using NADPH, tying the couple’s recovery rate to pyridine-nucleotide availability (Pei et al., 2023, PMID 36937839); MOTS-c, whose research intersects this pathway through Nrf2 — Nrf2/Keap1–ARE stabilisation coordinately induces the GCL catalytic and modifier subunits that build glutathione (Wild, Moinova & Mulcahy, 2000, PMID 10741850), and an engineered LAT1-targeted MOTS-c analogue activated Nrf2 and preserved GSH and SOD levels in irradiated mouse lung (Zhang et al., 2026, PMID 42142418) — note carefully: that study used the engineered R13A-MOTS-c analogue rather than wild-type MOTS-c, and glutathione peroxidase was not among the enzymes measured; and SS-31 (Elamipretide), which binds cardiolipin and limits its peroxidation, a process counter-balanced in vivo by the GSH/GPX4 axis — GPX4 being the sole enzyme reducing membrane phospholipid hydroperoxides (Yang et al., 2014, PMID 24439385). SS-31 protects the membrane structurally; glutathione is the soluble reducing pool that chemistry draws on.
That same γ-glutamyl linkage makes delivery the central scientific problem of this compound — more interesting than the molecule. Intact GSH is degraded almost exclusively extracellularly, by γ-glutamyltransferase at the cell surface, to cysteinylglycine and then to amino acids that must be re-imported and resynthesised intracellularly (Inoue, 2016, PMID 27095217). The cycle is, in effect, a hydrolytic gate. A single 3 g oral dose in seven volunteers produced no meaningful rise in plasma glutathione, cysteine, or glutamate over 270 minutes (Witschi et al., 1992, PMID 1362956 — n = 7, acute single-dose pharmacokinetics only; reported context, not a protocol). Chronic exposure shifts stored pools modestly and reversibly: a 6-month randomised trial in 54 subjects raised glutathione across whole-blood, erythrocyte, plasma, lymphocyte, and buccal compartments, with values returning toward baseline after washout (Richie et al., 2015, PMID 24791752) — a store shift, not a new steady state, and one a placebo-controlled oral trial failed to reproduce on any oxidative-stress biomarker (Allen & Bradley, 2011, PMID 21875351). Routes bypassing intestinal GGT behave differently: sublingual delivery raised plasma glutathione and the GSH/GSSG ratio relative to oral in a 20-subject crossover (Schmitt et al., 2015, PMID 26262996) — the gate, rather than the molecule, is the operative variable. Delivery is nonetheless no surrogate for effect: a 6-month nebulised trial in 153 subjects confirmed sputum delivery yet found no difference in FEV₁, exacerbations, or quality of life (Griese et al., 2013, PMID 23631796).
Compartmentation compounds the problem. Mitochondria possess no glutathione synthetic machinery and must import GSH across the inner membrane via the dicarboxylate and 2-oxoglutarate carriers, against a charge gradient, to maintain roughly 10–15% of cellular glutathione — the principal defence against respiratory-chain superoxide (Lash, 2006, PMID 16600197; Ribas et al., 2014, PMID 25024695). Selective mitochondrial depletion sensitises cells even where total cellular glutathione appears unchanged, so whole-blood or plasma glutathione — the endpoint most supplementation work reports — is a poor proxy for the compartment that determines cell fate.
One methods point deserves stating plainly, since it silently undermines much published redox-ratio data. Measured GSSG — and therefore the GSH/GSSG ratio — is substantially a sample-handling artefact. Reported blood GSSG spans roughly 1 to more than 500 µmol/L, a spread attributable largely to method rather than biology (Rossi et al., 2002, PMID 11978601), and 5–15% of sample glutathione is artefactually oxidised during acid deproteination unless thiols are blocked first — preventable by N-ethylmaleimide derivatisation ahead of deproteination, with dichloromethane back-extraction (Giustarini et al., 2013, PMID 23928499). A redox-ratio endpoint is interpretable only where the workup blocks thiol oxidation before acid precipitation; the derivatisation chemistry belongs alongside every reported GSH/GSSG value.



Reviews
There are no reviews yet.