Glutathione is the most-produced antioxidant in the human body and one of the least well-supported things to inject. It is a tripeptide rather than a signalling peptide, it has a measured intravenous half-life of about fourteen minutes, there is no FDA-approved injectable glutathione product in the United States, and the most recent systematic review of its best-known use concludes that the intravenous route is contraindicated. This guide compiles the published evidence - including the routes the studies actually used and the ones they cannot hold - alongside what the primary literature actually establishes. Educational content for research use only; not medical advice and not a protocol.
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Glutathione Guide: Available Now
Educational use only — not medical advice. This guide summarizes information reported in published research and community practice for educational purposes. It is not medical advice and not a recommendation to use any compound. Any doses, schedules, or combinations shown are examples of what has been reported, not instructions for you. Many peptides described here are research compounds that are not FDA-approved for the uses discussed and may be investigational or restricted. Effects, risks, and legal status vary; individual needs and results vary. Consult a qualified, licensed healthcare professional before making any decision. Do not use this content to diagnose, treat, or dose yourself.
Glutathione at a glance
What it is
A tripeptide, gamma-L-glutamyl-L-cysteinyl-glycine (C10H17N3O6S, 307.32 Da) - the body's principal intracellular antioxidant, synthesised endogenously rather than acting as a signalling peptide
Structural quirk
The glutamate is joined through its side-chain carboxyl (a gamma-linkage), not the usual alpha peptide bond, which is why it resists ordinary peptidases
Plasma half-life
Measured at 14.1 +/- 9.2 minutes in 10 healthy volunteers after a 2 g/m2 intravenous infusion (Eur J Clin Invest 1991)
Where it goes
Largely out. Urinary glutathione excretion rose roughly 300-fold in the 90 minutes after infusion in that same study
US regulatory status
No FDA-approved injectable glutathione product exists. A DailyMed search returns homeopathic preparations, oral liquids and skin-lightening cosmetics - not an approved parenteral drug
Skin-lightening evidence
A 2025 systematic review found only one placebo-controlled IV study (37.5% vs 18.7%, p = 0.054) and concluded that "IV glutathione is contraindicated due to lack of efficacy and side effects"
Where oral did better
The same review found five RCTs of oral glutathione at 250 mg once or twice daily or 500 mg once daily showing significant melanin-index reduction versus placebo
Parkinson's evidence
A randomised placebo-controlled pilot of IV glutathione 1,400 mg three times weekly for four weeks found no significant UPDRS difference (Mov Disord 2009)
Educational reference. This page does not publish dose ranges or reconstitution arithmetic.
What it is / mechanism
Glutathione is not a peptide in the sense that most compounds in this library are. It is not a hormone analogue, a receptor agonist or a signalling molecule engineered from a native sequence. It is a tripeptide - gamma-L-glutamyl-L-cysteinyl-glycine, molecular formula C10H17N3O6S, molecular weight 307.32 - that every nucleated cell in the body manufactures for itself, in millimolar intracellular concentrations, as its principal thiol antioxidant and conjugation substrate.
One structural detail explains a great deal about how it behaves. The bond between glutamate and cysteine is a gamma-linkage: it forms through the glutamate side-chain carboxyl rather than the alpha-carboxyl used in ordinary peptide bonds. Most peptidases cannot cleave it. The enzyme that can, gamma-glutamyl transpeptidase, sits on the outer surface of cell membranes, particularly in kidney and liver - which means extracellular glutathione is not taken up intact so much as taken apart at the cell surface, its constituent amino acids transported in and reassembled inside.
That is the mechanism that matters for anything injected, and the human pharmacokinetic study makes it concrete. When Aebi and colleagues infused 2 g/m2 of reduced glutathione into ten healthy volunteers (Eur J Clin Invest 1991, PMID 1907548), plasma total glutathione rose from 17.5 to 823 micromol/L - a roughly fiftyfold increase - and plasma cysteine rose from 8.9 to 114 micromol/L. But total cyst(e)ine in plasma, counting cysteine, cystine and mixed disulphides together, actually decreased, which the authors interpreted as increased uptake of cysteine from plasma into cells. Meanwhile urinary excretion of glutathione increased about 300-fold in the following 90 minutes.
Read together, that describes parenteral glutathione less as antioxidant replacement than as a cysteine delivery vehicle with substantial renal loss. The authors' own framing is that "parenteral glutathione has therapeutic potential for targeted delivery of cysteine equivalents," and that the resulting high intracellular cysteine concentration is what protects against cisplatin and oxazaphosphorine toxicity - the clinical use the study was designed to explain. Cysteine is the rate-limiting substrate for a cell making its own glutathione. Supplying the finished tripeptide from outside largely results in it being disassembled, partly absorbed as parts, and substantially excreted.
Researched effects
The evidence base for injected glutathione is unusually easy to summarise, because there is little of it and the most rigorous parts are negative.
Skin lightening is the dominant use and the best-reviewed. A 2025 systematic review in the International Journal of Dermatology (PMID 39444151) searched PubMed, Embase and the Cochrane library for ten years of evidence on glutathione as a skin-lightening agent and in melasma, and assessed level of evidence, strength of recommendation and risk of bias. Its findings by route are the clearest statement available. On oral glutathione, five randomised controlled trials and one open-arm study at 250 mg once daily, 250 mg twice daily and 500 mg once daily "showed a significant reduction in the melanin index compared to placebo." On topical, 0.5% glutathione was significantly more effective than 0.1% and than placebo, and topical 2% combined with oral was superior to either alone. On the intravenous route there was "only one placebo-controlled study," reporting 6 of 16 (37.5%) versus 3 (18.7%) with a p value of 0.054 - a result that did not reach significance. The review's conclusion is quoted here in full because it is the single most decision-relevant sentence on this page: "IV glutathione is contraindicated due to lack of efficacy and side effects."
That conclusion is not new. A 2018 review in Dermatology Practical and Conceptual (PMID 29445569) had already found that the clinical evidence for intravenous glutathione in skin lightening was "limited to a single study with a dubious study design and apparently flawed analysis of results," while noting that oral, sublingual and topical routes had reported good safety and "appreciable but reversible" results. It also records the regulatory backdrop: parenteral glutathione is approved in some jurisdictions only for severe liver disorders and for prevention of chemotherapy-associated neurotoxicity, and its use for skin lightening has drawn statutory bans or advisories from several national agencies. Two independent reviews, seven years apart, reached the same conclusion about the same route.
The neurological literature tells a similar story with a better-designed study. Hauser and colleagues ran a randomised, double-blind, placebo-controlled pilot of intravenous glutathione at 1,400 mg three times a week for four weeks in Parkinson's disease patients whose motor symptoms were inadequately controlled (Mov Disord 2009, PMID 19230029). Twenty-one subjects were randomised, 11 to glutathione and 10 to placebo. There were no significant differences in Unified Parkinson's Disease Rating Scale scores. Over the four treatment weeks, UPDRS activities-of-daily-living plus motor scores improved by a mean of 2.8 units more in the glutathione group (p = 0.32); over the subsequent eight weeks they worsened by a mean of 3.5 units more in the glutathione group (p = 0.54). Glutathione was well tolerated with no withdrawals for adverse events. The authors' honest reading was that the data "suggest the possibility of a mild symptomatic effect, but this remains to be evaluated in a larger study." That larger study has not followed in the seventeen years since.
What the evidence does support, and what is worth separating out, is the oncology-supportive use that the pharmacokinetic work was built around: high-dose parenteral glutathione protecting against the nephrotoxic and urotoxic effects of cisplatin and oxazaphosphorines. That is a specific, mechanistically coherent application - cysteine delivery to cells under oxidative assault from a known toxin - and it is not the same claim as systemic antioxidant supplementation or cosmetic lightening.
Evidence & regulatory status
Aebi S, Assereto R, Lauterburg BH. High-dose intravenous glutathione in man. Pharmacokinetics and effects on cyst(e)ine in plasma and urine. Eur J Clin Invest. 1991 Feb;21(1):103-10 (PMID 1907548). Ten healthy volunteers, 2 g/m2 intravenous infusion. The only human pharmacokinetic dataset cited on this page and the source for every kinetic figure: plasma total glutathione 17.5 +/- 13.4 to 823 +/- 326 micromol/L; volume of distribution 176 +/- 107 mL/kg; elimination rate constant 0.063 +/- 0.027 per minute corresponding to a half-life of 14.1 +/- 9.2 minutes; plasma cysteine 8.9 +/- 3.5 to 114 +/- 45 micromol/L; total cyst(e)ine decreasing despite the cysteine rise; urinary glutathione excretion increased 300-fold and cyst(e)ine 10-fold over 90 minutes.
Sarkar R, Yadav V, Yadav T, P J, Mandal I. Glutathione as a skin-lightening agent and in melasma: a systematic review. Int J Dermatol. 2025 Jun;64(6):992-1004 (PMID 39444151). Systematic review across PubMed, Embase and Cochrane with level-of-evidence and risk-of-bias assessment. Source for the oral RCT results at 250 mg once daily, 250 mg twice daily and 500 mg once daily; the topical 0.5% versus 0.1% versus placebo comparison; the single placebo-controlled IV study result of 6/16 (37.5%) versus 3 (18.7%), p = 0.054; and the conclusion that "IV glutathione is contraindicated due to lack of efficacy and side effects."
Sonthalia S, Jha AK, Lallas A, Jain G, Jakhar D. Glutathione for skin lightening: a regnant myth or evidence-based verity? Dermatol Pract Concept. 2018 Jan 31;8(1):15-21 (PMID 29445569). Source for the assessment that IV evidence is "limited to a single study with a dubious study design and apparently flawed analysis of results," for the note that parenteral glutathione is approved only for severe liver disorders and prevention of chemotherapy-associated neurotoxicity in the jurisdictions where it is approved at all, and for the existence of statutory bans and advisories from national regulators.
Hauser RA, Lyons KE, McClain T, Carter S, Perlmutter D. Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson's disease. Mov Disord. 2009 May 15;24(7):979-83 (PMID 19230029). Source for the 1,400 mg three-times-weekly four-week regimen, the 11-versus-10 randomisation, the null UPDRS result and both directional figures with their p values.
Sharma D, Daram S, Sharma P. Systemic Inflammatory Response Syndrome Following High-Dose Intravenous Glutathione-Containing Revitalising Solution in a Patient on Tirzepatide: A Case Report. Cureus. 2025 May 24;17(5):e84736 (PMID 40556995). Source for the adverse-event case described in the side-effects section, including all laboratory values and the authors' hypothesis regarding endotoxin contamination of an unregulated product.
DailyMed structured product label search for "glutathione", run 2026-08-14: 57 results, comprising homeopathic combination preparations, oral liquids, skin-lightening soaps and cosmetic serums. No FDA-approved injectable glutathione drug product appears.
The systematic reviews above are secondary sources, cited deliberately as such: for a compound whose primary literature consists largely of small, heterogeneous, high-risk-of-bias studies, a formal review with an explicit risk-of-bias assessment is a more honest basis than selecting individual favourable trials. The two primary studies cited directly - Aebi 1991 and Hauser 2009 - are the pharmacokinetic dataset and the one randomised controlled trial with a hard clinical endpoint.
Research timeline
Dated milestones taken from the primary records: the molecule's discovery, its first registered human study, the trials that shaped the evidence and the regulatory decisions. Each entry links to the record it comes from.
A study in seven healthy volunteers finds that glutathione taken by mouth did not raise blood glutathione, cysteine or glutamate, concluding that its systemic availability is negligible because gut and liver enzymes break it down. PMID 1362956
A placebo-controlled, double-blind crossover trial in 20 infertile men with varicocele or genital-tract inflammation reports a statistically significant positive effect of injected glutathione on sperm motility measures over two months. PMID 8300824
A randomised, double-blind pilot trial of intravenous glutathione in 21 people with Parkinson's disease finds it well tolerated but with no significant difference from placebo in Parkinson's rating scores over four weeks. PMID 19230029
A Phase 2b double-blind trial of intranasal glutathione in 45 people with Parkinson's disease finds all groups improved, placebo included, and neither glutathione group better than placebo. PMID 28436395
An Australian public-health case series reports seven probable cases of endotoxin poisoning linked to contaminated compounded glutathione infusions, five of them in people using the infusions for Lyme disease. PMID 29673413
FDA's 503A list, as updated on this date, lists glutathione in Category 1: a bulk substance still under evaluation for pharmacy compounding, not one FDA has approved or added to the list. FDA · 503A categories, May 14, 2026
Records checked Oct 4, 2026
Claims at a glance
The claims most often made about this compound, each with the strongest kind of evidence we found for it. The grade says what was studied, not whether the claim is true; the line beside it says what that study showed.
Lightens skinHuman, randomised trial. Randomised trials of glutathione by mouth lowered a skin-pigment measure; the one placebo-controlled intravenous study was not significant, a 2025 systematic review found. PMID 39444151
Improves Parkinson's diseaseHuman, randomised trial. In the randomised double-blind trial of intravenous glutathione, 21 patients, symptom scores did not differ from placebo. PMID 19230029
Protects the nerves during chemotherapyHuman, randomised trial. Small trials with platinum drugs reported less nerve damage, but the only phase 3 trial, with paclitaxel and carboplatin, found no benefit and two outcomes favoured placebo. PMID 24619793
Protects the heartHuman, randomised trial. In a randomised pilot of 50 heart-attack patients, infusions before angioplasty lowered blood markers of oxidative stress and heart-muscle damage; no clinical outcome was the endpoint. PMID 31399448
Strengthens the immune systemHuman, randomised trial. In a six-month randomised trial of glutathione by mouth, natural-killer-cell activity more than doubled in the higher-dose group, a secondary measure. PMID 24791752
Improves male fertilityHuman, non-randomised. A 1993 placebo-controlled crossover study of injections in 20 infertile men reported better sperm motility and shape; it has not been repeated. PMID 8300824
Detoxifies and restores energy as a dripNo study found. A PubMed search for randomised trials of injected glutathione on fatigue, energy, detoxification or ageing returned one record, a chemotherapy study. PubMed search, Oct 7, 2026
The reasoning behind each grade, study by study, is in this guide's Benefit & Outcome Review.
Grades checked Oct 7, 2026
A printable reference sheet with the compound's key facts, storage guidance and a vial record comes with All-Access Lifetime.
Half-life & pharmacokinetics
Glutathione's intravenous half-life has been measured directly in humans, which makes it one of the better-characterised figures in this library - and one of the shortest.
In ten healthy volunteers given 2 g/m2 as an intravenous infusion, the elimination rate constant was 0.063 +/- 0.027 per minute, corresponding to a half-life of 14.1 +/- 9.2 minutes (Eur J Clin Invest 1991, PMID 1907548). The volume of distribution of exogenous glutathione was 176 +/- 107 mL/kg - substantially less than total body water, indicating that infused glutathione largely stays in the extracellular compartment rather than distributing into cells as the intact tripeptide.
The standard deviation deserves as much attention as the mean. A half-life of 14.1 with an SD of 9.2 across ten subjects is wide variability, and it should be read as "minutes, not hours" rather than as a precise constant.
The elimination picture is completed by the urinary data, and this is the part most often omitted. Urinary excretion of glutathione increased approximately 300-fold in the 90 minutes following the infusion. A large proportion of a parenteral amount appears in urine essentially intact and quickly. The authors treated that as mechanistically useful for the oncology application - raising sulphydryl concentrations in the urinary tract is precisely what protects against urotoxic chemotherapy - but for any systemic antioxidant rationale it is the opposite of what is wanted.
What did persist in a useful form was cysteine. Plasma cysteine rose from 8.9 to 114 micromol/L after infusion, while total plasma cyst(e)ine fell, which the authors read as increased cellular uptake of cysteine. That is the durable effect of an infusion: not a sustained elevation of circulating glutathione, but a transient flood of the amino acid that cells need to make their own.
No half-life figure exists for intramuscular or subcutaneous glutathione, and none for oral. For oral, the relevant question is different anyway - whether the intact tripeptide survives gastrointestinal transit and first pass at all is contested, though the oral trials that showed melanin-index effects did so at 250-500 mg daily, which is an observation about outcome rather than about absorption.
Reported side effects & toxicology
Glutathione was well tolerated in the two controlled studies that recorded tolerability. In the Parkinson's disease trial there were no withdrawals for adverse events in either arm, and reported adverse events were similar between the glutathione and placebo groups. The pharmacokinetic study in healthy volunteers reported no safety concerns at 2 g/m2. Whatever else is true about injected glutathione, an appropriately manufactured product administered in a controlled setting has not shown a distinctive toxicity signal.
The risk that has produced documented harm is a different one, and it belongs to the product rather than the molecule. A 2025 case report in Cureus (PMID 40556995) describes systemic inflammatory response syndrome following administration of a high-dose unregulated intravenous glutathione infusion marketed for skin lightening. A previously healthy woman collapsed within an hour of the infusion, presenting with shock and hyperpyrexia above 41 C. Laboratory findings included a white cell count of 26 x 10^9/L, C-reactive protein of 160 mg/L, procalcitonin of 28.8 micrograms/L, alanine transaminase of 311 IU/L indicating acute liver injury, and a prothrombin time of 26.4 seconds indicating coagulopathy. No infectious source was identified. She recovered fully with supportive care. The authors hypothesised that the syndrome resulted either from endotoxin contamination of the unregulated product or from a synergistic effect with the patient's circumstances - she had been self-administering tirzepatide with consequent prolonged low nutritional intake.
That case is included here rather than filed as an outlier because its details map closely onto this site's readership: an unregulated injectable product, obtained outside a regulated supply chain, administered to someone also using a research-market GLP-1 compound. The suspected mechanism - endotoxin contamination - is a manufacturing and sterility failure, not a pharmacological property of glutathione. It is the specific hazard that quality of product and quality of diluent exist to address.
The 2025 systematic review's conclusion that "IV glutathione is contraindicated due to lack of efficacy and side effects" should be read with both halves intact. The efficacy half is well supported by the review's own evidence table. The side-effects half rests on a thinner base than the efficacy half does - the controlled studies found good tolerability, and the serious documented harms trace to unregulated products rather than to the compound. The honest summary is that the case against injecting glutathione is primarily that it has not been shown to work by that route, and secondarily that the products used to do it are frequently outside any quality system.
One regulatory note completes the picture: several national agencies have issued advisories or bans against intravenous glutathione for skin lightening, as recorded in the 2018 review. Those actions are aimed at the cosmetic-infusion market specifically.
Storage & handling
Lyophilised glutathione is typically stored refrigerated at 2-8 C, protected from light, before reconstitution. As a hygroscopic powder it should be kept tightly closed and allowed to reach room temperature before the vial is opened, so that atmospheric moisture does not condense into a cold vial.
Oxidation is the specific stability problem for this compound, and it is different from the degradation concerns that apply to the rest of this library. Reduced glutathione converts readily to its oxidised disulphide form, glutathione disulphide, on exposure to air. Every study cited on this page administered the reduced form. A solution that has stood, been repeatedly entered or been agitated with air has shifted toward the oxidised form to an unknown degree, and there is no way to tell by looking.
That argues for preparing solutions close to use and minimising headspace exposure, rather than reconstituting a large volume for repeated entry over weeks - which is a genuinely different handling posture from the one that suits most peptides in this library.
Where a vial will be entered more than once, a preserved diluent is the relevant category. Bacteriostatic Water for Injection, USP is preserved with 0.9% benzyl alcohol and is conventionally treated as good for 28 days after first puncture when refrigerated. Sterile water contains no preservative and does not support repeated entry into a multiple-dose vial on any timeline. Our comparison of the two is at the bacteriostatic water vs sterile water guide.
The preservative addresses microbial growth, not oxidation. Those are two independent failure modes, and bacteriostatic water solves only the first. For glutathione specifically, the second is the one more likely to change what is actually in the syringe.
References
Primary sources for this page, with what each one supports.
Human pharmacokinetics: Aebi S, Assereto R, Lauterburg BH. High-dose intravenous glutathione in man. Pharmacokinetics and effects on cyst(e)ine in plasma and urine. Eur J Clin Invest. 1991 Feb;21(1):103-10 (PMID 1907548). Every kinetic figure on this page comes from this study of ten healthy volunteers given 2 g/m2 intravenously: plasma total glutathione rising from 17.5 +/- 13.4 to 823 +/- 326 micromol/L; volume of distribution 176 +/- 107 mL/kg; elimination rate constant 0.063 +/- 0.027 per minute corresponding to a half-life of 14.1 +/- 9.2 minutes; plasma cysteine rising from 8.9 +/- 3.5 to 114 +/- 45 micromol/L while total cyst(e)ine fell, interpreted as increased cellular uptake; and urinary excretion of glutathione and cyst(e)ine increased 300-fold and 10-fold respectively over the following 90 minutes. The study's stated purpose - explaining how parenteral glutathione protects against cisplatin and oxazaphosphorine toxicity - is also the source for this page's framing of glutathione as a cysteine delivery vehicle.
Systematic reviews: PMID 39444151 (Int J Dermatol 2025) for the route-by-route efficacy findings and the quoted conclusion on the intravenous route. PMID 29445569 (Dermatol Pract Concept 2018) for the assessment of the single IV study, the approved-indication note, and the record of national regulatory advisories.
Randomised controlled trial: PMID 19230029 (Mov Disord 2009) for the Parkinson's disease pilot, its regimen, its null primary result and both directional figures with p values.
Case report: PMID 40556995 (Cureus 2025) for the systemic inflammatory response syndrome case following an unregulated high-dose intravenous glutathione infusion, all quoted laboratory values, the tirzepatide context and the authors' endotoxin-contamination hypothesis.
Regulatory status: DailyMed structured product label search for "glutathione", run 2026-08-14, returning 57 products - homeopathic preparations, oral liquids, soaps and cosmetic serums - and no FDA-approved injectable drug product.
A note on source selection. This page cites two systematic reviews directly rather than assembling its own reading of the underlying trials. That is deliberate: the primary literature on injected glutathione consists largely of small, heterogeneous studies with, in the 2025 review's own risk-of-bias assessment, roughly equal numbers at low and high risk of bias. Where a formal review with a stated methodology exists, it is a more honest basis than a selection of individual trials. The two studies cited directly are the only human pharmacokinetic dataset and the only randomised controlled trial with a hard clinical endpoint.
Page content last verified against primary sources: 2026-08-14.
Evidence File
The Glutathione Evidence File: Every Injected-Route Trial, Traced and Weighed
The free guide is built on two systematic reviews, one pharmacokinetic study and one randomised trial. This file goes to the primary record: the human trial history of injected glutathione across oncology, cardiology, vascular disease and fertility - plus the liver record, which turns out to be oral - reconstructed study by study with verbatim results, plus a full ClinicalTrials.gov census of what is actually registered today. It follows a thirty-year arc from small single-centre trials to a multicentre phase 3, tracks the Parkinson programme through its change of route, resolves the oral-versus-injected absorption dispute through three studies that disagree, and names the searches that establish what has never been studied at all.
18 human studies cited by PMID in this file
268 glutathione intervention records screened on ClinicalTrials.gov
0 registered trials of subcutaneous glutathione, the commonest community route
185 patients in the largest injected-glutathione trial, which was negative
What this file adds to the free page
The platinum years: cisplatin and oxaliplatin neuroprotection, 1992-2002
The phase 3 that reversed the story: Alliance N08CA
Parkinson's disease: from an N of 9 to a null, then a change of route
The scattered singles: fertility, walking distance, liver
The one serious current programme: high-dose glutathione in heart attack
The oral absorption contradiction, resolved by dates
The registry census, and what has never been studied at all
8 more sections in the Evidence File for Glutathione
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Glutathione for $14 — or every compound in the library, plus the printable reference sheets, for $99.
The sections above this one stay free to read without an account.
Sourcing File
The Glutathione Sourcing File: Identity Numbers, the Oxidation Trap, and What a Certificate Must Show
Glutathione's quality problem is not the one most peptides have. This file assembles the verified identity numbers - registry identifiers, formula, exact masses and adduct values cross-checked against PubChem - and then works through the failure modes specific to this molecule: the degradation route that a standard purity line can miss, a mass-spectrometry coincidence that can fool a low-resolution identity check, an assay method still in common use that cannot distinguish glutathione from its own breakdown products, salt-versus-free-acid label arithmetic worked to the milligram, and the documented contamination record that makes one particular certificate line non-negotiable for this compound above all others.
5 named impurities in the FDA method panel recounted in this file
7 probable endotoxin poisoning cases in a single documented cluster
~7% overstatement when a vial is labelled by sodium-salt weight instead of free acid
0.05% quantitation limit, w/w, of the FDA impurity method a good lab can match
The verified identity numbers
The disulfide problem, and a mass-spec coincidence worth knowing
The FDA impurity panel: five names a certificate should recognise
Near-mass relatives and the salt arithmetic, worked
The documented harm mode is the vial, not the molecule - and it is recurrent
Reading a glutathione certificate, line by line
6 more sections in the Sourcing File for Glutathione
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Glutathione for $14 — or every compound in the library, plus the printable reference sheets, for $99.
The sections above this one stay free to read without an account.
Benefit & Outcome Review
The Glutathione Benefit and Outcome Review: Every Circulating Claim, Scored
Glutathione carries more marketed claims per milligram than almost anything else in this library - skin, brain, liver, heart, fertility, immunity, energy, detox, longevity. This review takes each claim in turn and scores it against the controlled human record, with the verdict tied to route and dose, because for this compound the route changes the answer. It also runs the exercise the marketing never does: tracing the five most-repeated glutathione numbers back to the studies they came from, and setting the trial regimens that generated the data side by side with the community protocols that cite them.
0 injected-glutathione trials for any detox, energy, fatigue or anti-aging endpoint
1 published phase 3 trial of injected glutathione, and it was negative
9 patients behind the most-quoted glutathione figure in circulation
5 circulating figures traced to their origin studies in this review
How the scoring works
Skin lightening: the route decides the verdict
Parkinson's disease and the 42 percent figure
Chemotherapy neuroprotection: the one real signal, and its edges
The plausible-unproven cluster: heart, vessels, fertility, liver, immunity
Detox, energy, fatigue, anti-aging: the empty quadrant
The five circulating figures, traced to origin
Trial regimens versus community practice: the mismatch in one view
8 more sections in the Benefit & Outcome Review for Glutathione
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Glutathione for $14 — or every compound in the library, plus the printable reference sheets, for $99.
Quick answers about guide scope, access, and educational use context.
What is the half-life of injected glutathione?
About 14 minutes. In ten healthy volunteers given a 2 g/m2 intravenous infusion, the measured elimination rate constant was 0.063 +/- 0.027 per minute, giving a half-life of 14.1 +/- 9.2 minutes (Eur J Clin Invest 1991). The variability is wide, so the figure is best read as minutes rather than as a precise constant. Urinary glutathione excretion also rose roughly 300-fold in the 90 minutes after infusion, so a large share of an injected amount is excreted rather than retained.
Is there an FDA-approved glutathione injection?
No. There is no FDA-approved injectable glutathione drug product in the United States. A DailyMed search for glutathione returns 57 labelled products consisting of homeopathic combination preparations, oral liquids, skin-lightening soaps and cosmetic serums - no approved parenteral drug. Injectable glutathione in circulation is compounded, imported or sold as a research chemical, with no FDA-established dose, strength or quality specification. In jurisdictions where parenteral glutathione is approved at all, the approved indications are severe liver disorders and prevention of chemotherapy-associated neurotoxicity.
Does IV glutathione work for skin lightening?
The evidence says no. A 2025 systematic review in the International Journal of Dermatology found only one placebo-controlled study of the intravenous route, reporting 6 of 16 (37.5%) versus 3 (18.7%) with p = 0.054 - not statistically significant - and concluded that "IV glutathione is contraindicated due to lack of efficacy and side effects." A 2018 review had already characterised the IV evidence as "limited to a single study with a dubious study design and apparently flawed analysis of results." By contrast, the same 2025 review found five randomised trials of oral glutathione at 250 mg once or twice daily or 500 mg once daily showing significant melanin-index reduction versus placebo, and topical 0.5% outperforming both 0.1% and placebo.
Why did the injected-glutathione studies use intravenous infusion?
Because of volume. Glutathione is studied at hundreds of milligrams rather than hundreds of micrograms — far more than a small subcutaneous injection carries — which is why every study of injected glutathione used intravenous infusion.
Why are glutathione doses so much larger than other peptides?
Because it is not doing the same kind of job. Signalling peptides bind receptors at nanomolar concentrations, so microgram amounts suffice. Glutathione is a metabolic substrate present intracellularly at millimolar concentrations throughout the body, so meaningful supplementation requires amounts roughly a thousand times larger - hundreds of milligrams rather than hundreds of micrograms. That difference in scale is what makes glutathione's practical handling, route and syringe requirements unlike anything else in this library.
What happened in the Parkinson's disease trial?
Hauser and colleagues randomised 21 patients with inadequately controlled motor symptoms to intravenous glutathione 1,400 mg three times weekly or placebo for four weeks (Mov Disord 2009). There were no significant differences in UPDRS scores. Over the treatment period, activities-of-daily-living plus motor scores improved by a mean of 2.8 units more in the glutathione group (p = 0.32); over the following eight weeks they worsened by 3.5 units more in the glutathione group (p = 0.54). Glutathione was well tolerated with no adverse-event withdrawals. The authors concluded a mild symptomatic effect was possible but needed evaluation in a larger study - which has not been published in the years since.
Is glutathione actually a peptide?
Yes, technically - it is a tripeptide of glutamate, cysteine and glycine - but it is not a signalling peptide like the rest of this library. It has no receptor, it is not a hormone analogue, and every cell manufactures it endogenously. It also has an unusual structure: the glutamate is linked through its side-chain carboxyl rather than the standard alpha peptide bond, which makes it resistant to ordinary peptidases and means extracellular glutathione is largely broken down at cell surfaces by gamma-glutamyl transpeptidase rather than absorbed intact.
What are the risks of injecting glutathione?
In controlled studies with properly manufactured product, tolerability was good - no adverse-event withdrawals in the Parkinson's trial and no safety concerns in the pharmacokinetic study. The documented serious harm comes from unregulated products. A 2025 case report describes systemic inflammatory response syndrome after a high-dose unregulated intravenous glutathione infusion given for skin lightening: shock, hyperpyrexia above 41 C, white cell count 26 x 10^9/L, CRP 160 mg/L, procalcitonin 28.8 micrograms/L, ALT 311 IU/L and prothrombin time 26.4 seconds, with no infectious source found and full recovery on supportive care. The authors hypothesised endotoxin contamination of the product. That is a sterility and manufacturing failure rather than a property of the molecule.
Is oral glutathione better than injected?
For the skin-lightening endpoint, the controlled evidence is better for oral than for intravenous - five randomised trials at 250-500 mg daily showed significant melanin-index reduction versus placebo, while the single placebo-controlled IV study did not reach significance. That is a statement about which route has supporting trials, not a claim that oral glutathione is well absorbed; whether the intact tripeptide survives gastrointestinal transit is genuinely contested. The 2025 review also found topical 2% combined with oral superior to either alone.
Can I use bacteriostatic water for glutathione?
Bacteriostatic Water for Injection, USP is the appropriate category for any vial that will be entered more than once, since its 0.9% benzyl alcohol addresses microbial growth across repeated entries where sterile water cannot. The caveat specific to glutathione is that the preservative does nothing about its main stability problem, which is oxidation of the reduced form to the disulphide. Those are independent failure modes. Minimising air exposure, keeping solutions cold and dark, and preparing closer to use address the oxidation side; the diluent choice addresses only the microbial side.
Compliance and trust notes
Educational content only; no personalized health or outcome claims.
No personalized use recommendation outputs.
Use this material for general learning and research-context literacy.
A certificate of analysis (COA) is a laboratory’s report on one sample of one batch. The single most useful thing to know about it is that purity and identity are two separate results that fail in different ways. A high purity figure says the sample was mostly one substance; it does not say that substance was Glutathione. Identity — normally a mass-spectrometry result matching the expected molecular weight — is what establishes what the material actually is, and a certificate reporting purity alone has not answered that question.
Two further limits are worth holding onto. Mass per vial is its own test: a vial can be 99% pure and still contain less material than the label claims. And sterility, endotoxin, heavy metals and residual solvent screening are separately commissioned tests, usually priced individually — so a “third-party tested” badge asserts none of them unless the certificate names them. Check that the batch or lot number on the document matches the vial in front of you; an unmatched certificate describes someone else’s material.
Medibact does not test, endorse or resell peptides, and publishes no rating of any laboratory. How to read a peptide certificate of analysis walks through the document section by section, and what each COA field establishes covers the field-by-field detail and the laboratories that publish their methods.
You’ll need bacteriostatic water
The diluent for reconstituting Glutathione
Reconstitution is volume arithmetic — it assumes a lyophilized vial is dissolved in bacteriostatic water, which is sterile water preserved with 0.9% benzyl alcohol. The preservative is what allows a vial to be entered more than once; plain sterile water carries none and is single-entry by design. Medibact supplies USP-grade Bacteriostatic Water for Injection in a 30 mL multi-dose vial, made in the United States and shipped from the United States, for research use only. One 30 mL vial covers 30 reconstitutions at 1 mL each, 15 at 2 mL, or 10 at 3 mL — division only, not a dosing recommendation.
Educational use only — not medical advice. This guide summarizes information reported in published research and community practice for educational purposes. It is not medical advice and not a recommendation to use any compound. Any doses, schedules, or combinations shown are examples of what has been reported, not instructions for you. Many peptides described here are research compounds that are not FDA-approved for the uses discussed and may be investigational or restricted. Effects, risks, and legal status vary; individual needs and results vary. Consult a qualified, licensed healthcare professional before making any decision. Do not use this content to diagnose, treat, or dose yourself.
