Glutathione Injection Dosage Chart: Reconstitution, Syringe Volumes & Half-Life

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)

Commonly reported range

Community injection reports describe ~200-600 mg per session, 1-3x weekly. The doses with data behind them are 1,400 mg IV three times weekly (Parkinson's trial, null result) and 250-500 mg daily orally (skin-lightening RCTs)

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)

Syringe warning

A 600 mg amount is not an insulin-syringe volume at most dilutions - at 2 mL and 3 mL reconstitution it requires 200 and 300 units respectively, beyond the 100-unit capacity of a U-100 syringe

Reported ranges from research/community — examples, not recommendations.

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.

Dosage — reported ranges (overview)

There is no approved injectable glutathione product in the United States, and therefore no approved dose. A DailyMed search for glutathione returns 57 labelled products - homeopathic combination remedies, oral liquids, skin-lightening soaps and cosmetic serums - and no parenteral drug. Any injectable glutathione in circulation is compounded, imported or sold as a research chemical, and none of it has an FDA-established dose, strength or quality specification. The doses that do appear in the literature come from studies rather than from labelling, and they are worth reporting precisely because they are the only figures with anything behind them. In the Parkinson's disease trial, the regimen was 1,400 mg intravenously three times a week for four weeks - and it produced no significant difference from placebo. In the human pharmacokinetic study, the infused amount was 2 g/m2 of body surface area, which for a typical adult is roughly 3.4 to 4 g in a single infusion, given to characterise kinetics rather than to treat anything. In the oral skin-lightening trials that did show an effect on melanin index, the doses were 250 mg once daily, 250 mg twice daily and 500 mg once daily. Community protocols for injectable research vials commonly describe amounts in the 200-600 mg range per administration, one to three times weekly, by intramuscular or subcutaneous injection. Those are reported conventions with no trial support and no regulatory standing; they are recorded here because they are what people are searching for, not because they are endorsed. Two facts about the numbers themselves deserve emphasis, because they are arithmetic rather than opinion and they shape everything practical about this compound. First, the masses are enormous by peptide standards. Most compounds in this library are dosed in micrograms; glutathione is dosed in hundreds of milligrams - a factor of roughly a thousand. That single difference is why glutathione behaves unlike anything else here at the syringe, and it is covered in the reconstitution section below. Second, the half-life is fourteen minutes and roughly 300 times the normal amount of glutathione appears in urine within ninety minutes of an infusion. Whatever an injected amount accomplishes, it accomplishes quickly, and a large share of it is excreted rather than retained. Increasing the amount injected does not change that; it changes how much is excreted.

A printable protocol sheet with a reconstitution reference and an injection log comes with All-Access Lifetime.

Reconstitution — bac-water math

The tables below assume a 600 mg vial, the size most commonly encountered, and a standard U-100 insulin syringe where 100 units equals 1 mL and each unit is 0.01 mL. Concentration is total milligrams divided by millilitres of diluent; volume to draw is the target amount divided by that concentration. Glutathione is the compound in this library where the syringe becomes the binding constraint, and the table below is left showing that rather than being quietly trimmed to fit. Because the amounts are measured in hundreds of milligrams rather than micrograms, the draw volumes are large. A 600 mg reference amount is exactly 1.0 mL at a 1 mL reconstitution - a completely full U-100 syringe - and at 2 mL and 3 mL reconstitutions it becomes 2.0 mL and 3.0 mL, which are 200 and 300 units. Those two cells are marked because a U-100 insulin syringe holds 100 units. They cannot be drawn in one go at all. That is not a flaw in the arithmetic; it is the physical reason glutathione is given by intravenous infusion or by intramuscular injection with a conventional syringe in every study on this page, rather than as a small subcutaneous injection. If a calculated volume does not fit an insulin syringe, the answer is not to use a larger insulin syringe - it is that the amount and the route are mismatched. The two reference amounts shown, 200 mg and 600 mg, are chosen to span the range that appears in community reporting and to make the volume problem visible. They are not recommendations. The site's reconstitution calculator will recompute all of this for any vial size and diluent volume.

This is concentration math, not a dose recommendation.

Injection / administration basics

Every study cited on this page used the intravenous route: 2 g/m2 by infusion in the pharmacokinetic work, 1,400 mg three times weekly by infusion in the Parkinson's trial, and infusion in the single placebo-controlled skin-lightening study the systematic review located. The intramuscular and subcutaneous routes that dominate community reporting have no comparable characterisation - no pharmacokinetic study, no controlled trial, and no bioavailability figure establishing what fraction of an intramuscular amount reaches circulation. The volume arithmetic in the reconstitution section is the practical reason that gap exists. Subcutaneous injection tolerates small volumes; a 600 mg amount at any reasonable concentration is not a small volume. This is a compound whose mass requirements and whose route of study point the same way, and away from the insulin syringe that most of this library uses. General handling information, reported rather than recommended: solutions are prepared immediately before use where possible, since reduced glutathione oxidises readily in solution to its disulphide form, and the reduced form is the one every study on this page administered. A solution that has been sitting is not necessarily the same solution chemically. This guide gives no dose, no schedule, no frequency and no route recommendation, and nothing here should be read as instructing administration to a person or an animal. The material is compiled for educational reference and research use only.

Half-life & frequency rationale

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.

Stacking — overview

Glutathione is most often discussed alongside other antioxidants and cofactors rather than alongside signalling peptides, and the rationale offered is usually substrate supply rather than receptor interaction. One mechanistic point is worth making because it follows from the pharmacokinetics rather than from convention. Since infused glutathione functions substantially as a cysteine delivery vehicle and is largely excreted intact, compounds that support endogenous glutathione synthesis operate on the same pathway from the other end - by supplying the rate-limiting substrate to cells that then assemble the tripeptide themselves. N-acetylcysteine is the most-studied compound in that role, and notably the Parkinson's literature has increasingly moved toward it rather than toward glutathione infusions in the years since the 2009 trial. The pairings below are reported conventions. None has been evaluated in a controlled trial in combination with glutathione, so there is no interaction, additive-effect or safety data for any of them. Our cross-compound Peptide Stacking Guide covers class-collision reasoning and the arithmetic of dosing from separate vials. The per-compound Stacking Module for glutathione is included with this guide's paid tier.

For how combinations are grouped by research context, the named blends, and why a pre-mixed blend vial cannot be calculated from its total milligrams, see the peptide stacks guide.

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.

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

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

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

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