TL;DR: A 600 mg glutathione vial with 3 mL of bacteriostatic water gives 200 mg/mL; a 1500 mg vial with 5 mL gives 300 mg/mL. Divide milligrams by millilitres — that is the entire formula. But because glutathione vials carry roughly a hundred times the mass of a typical research peptide, insulin units stop being a useful ruler: a single U-100 unit can carry 2-5 mg of compound. Work in mL instead and let the glutathione calculator do the conversion.
Why glutathione breaks the mcg-per-unit habit
Almost every dosing page on this site is built around one conversion: mcg per insulin unit. That works because research peptides are small in mass. A 5 mg BPC-157 vial reconstituted with 2 mL sits at 2.5 mg/mL, which is 25 mcg per unit on a U-100 syringe — a comfortable number where one tick of the plunger is a small, forgiving slice of the dose.
Glutathione is not that. It is a tripeptide (glutamate-cysteine-glycine, molecular weight 307.32 g/mol) that ships in gram-scale vials because the doses used in the literature are gram-scale. Reconstitute a 1500 mg vial in 3 mL and you are at 500 mg/mL — 5000 mcg per unit. Same syringe, same plunger, two hundred times the payload per tick.
That ratio is the whole article. Every quirk of glutatión reconstitución — awkward draw volumes, coarse resolution, powder that takes up real space in the vial — falls out of it.
The one formula, run on both vial sizes
Nothing about the arithmetic changes at high mg:
mg/mL = vial strength (mg) ÷ bacteriostatic water added (mL)
Run it across the diluent volumes people actually use:
- 600 mg + 2 mL = 300 mg/mL
- 600 mg + 3 mL = 200 mg/mL
- 600 mg + 6 mL = 100 mg/mL
- 1500 mg + 3 mL = 500 mg/mL
- 1500 mg + 5 mL = 300 mg/mL
- 1500 mg + 10 mL = 150 mg/mL
Then the draw volume for any target dose is just as simple:
mL to draw = target dose (mg) ÷ concentration (mg/mL)
No mcg, no unit conversion, no third step. The reconstitution chart covers the standard low-mg peptides; for gram-scale vials you are better off staying in these two lines.
Worked example: the 600 mg vial
Take a 600 mg vial and add 3 mL of bacteriostatic water. Concentration: 600 ÷ 3 = 200 mg/mL.
- A 200 mg dose: 200 ÷ 200 = 1.0 mL
- A 300 mg dose: 300 ÷ 200 = 1.5 mL
- A 600 mg dose: 600 ÷ 200 = 3.0 mL — the whole vial
That last line is worth sitting with, because 600 mg per administration is not an arbitrary number. Sechi and colleagues (1996) gave 600 mg of reduced glutathione intravenously, twice daily for 30 days, to nine people with early untreated Parkinson’s disease. The vial size on the market today is essentially that study’s per-dose unit, which is why 600 mg vials exist at all. Note the route: that protocol was intravenous infusion, not a subcutaneous draw, and 3 mL is far more than a subcutaneous depot comfortably takes.
If you want a smaller, repeatable draw from the same vial, reconstitute with less water: 600 mg + 2 mL = 300 mg/mL, so a 150 mg dose is 0.5 mL and you get four of them per vial. Vial specifics live on the glutathione 600mg page.
Worked example: the 1500 mg vial
The 1500 mg vial is where the instrument problem becomes obvious. Add 3 mL and you get 500 mg/mL. A 300 mg dose is then 300 ÷ 500 = 0.6 mL — 60 units on an insulin syringe, where each unit is 5 mg. Misread the barrel by two ticks and you are 10 mg off. That is trivial at this scale but it tells you the syringe is not doing useful work for you; you are using a precision instrument at the far end of its range.
Add 5 mL instead and you get 300 mg/mL, which is a much friendlier ruler:
- 300 mg → 1.0 mL (five doses per vial)
- 450 mg → 1.5 mL
- 600 mg → 2.0 mL
Hauser et al. (2009) ran the only randomized, double-blind, placebo-controlled evaluation of intravenous glutathione in Parkinson’s disease at 1400 mg three times weekly for four weeks — again, roughly one vial per administration. Twenty-one participants; glutathione was well tolerated but produced no significant difference in UPDRS scores versus placebo. Vial details on the glutathione 1500mg page.
Why the insulin syringe is the wrong instrument
A U-100 insulin syringe holds 1 mL, full stop. Fill it to the last tick at 200 mg/mL and you have 200 mg of glutathione.
100 units is the entire syringe: 1.0 mL, or 200 mg of a 600mg vial reconstituted in 3 mL. Anything larger needs a different barrel.
Two things follow. First, capacity: most glutathione volumes in the literature exceed what a 1 mL barrel holds, so you would be refilling mid-dose. Second, resolution: insulin syringes are graduated in units because insulin doses are tiny. At gram-scale concentrations that graduation buys you nothing — you are reading 1-5 mg per tick when your dose is measured in hundreds of milligrams.
The right tool is a graduated 3 mL or 5 mL luer-lock syringe marked in 0.1 mL increments. At 300 mg/mL, one 0.1 mL mark is 30 mg, which is a sane fraction of a 300 mg dose. Same logic that applies to any large-volume compound — see NAD+ injections versus NMN dosing, where the volume problem shows up for exactly the same reason.
Displacement: when the powder itself takes up room
Here is the wrinkle that only shows up on high-mg vials. With a 5 mg peptide, the lyophilized cake contributes essentially no volume — adding 2 mL of water gives you 2 mL of solution and nobody notices the difference. With 1500 mg of solid, that assumption breaks. Crystalline glutathione has a density on the order of 1.5 g/cm³, so a gram and a half of it occupies roughly a millilitre once dissolved.
Practically: add 3 mL of bacteriostatic water to a 1500 mg vial and your final volume is meaningfully more than 3 mL. If you calculate 500 mg/mL and the true figure is closer to 375 mg/mL, every draw is short by a quarter. The exact displacement depends on the salt form and any excipients, so do not trust a table for it — draw the reconstituted contents back into a graduated syringe, read the actual volume, and recompute:
true mg/mL = vial strength ÷ measured final volume
This is also why generous diluent volumes are the easier path on gram-scale vials. Reconstitute 1500 mg in 10 mL and a half-millilitre of displacement shifts your concentration by about 5%; do it in 2 mL and the same displacement shifts it by 20%. Bei der Glutathion Rekonstitution ist mehr Wasser fast immer die ruhigere Wahl.
What the evidence actually supports
Honest framing, because the dosing math is far more settled than the pharmacology:
Intravenous. Sechi’s 1996 open-label series (n=9, no blinding, no placebo arm) reported functional improvement; Hauser’s 2009 randomized double-blind pilot (n=21) found no significant UPDRS difference. Those are the two most-cited human injectable datasets and they point in different directions, with the more rigorous one being null.
Pharmacokinetics. Aebi and colleagues (1991) measured high-dose intravenous glutathione in humans and reported an elimination half-life of about 14 minutes, with urinary glutathione rising several hundred-fold within 90 minutes. Whatever a large bolus does, it does not linger in plasma — a point that any dosing schedule has to reckon with.
Oral. Richie et al. (2015), 54 adults over six months, found 250 mg/day and 1000 mg/day did raise glutathione in erythrocytes, plasma and lymphocytes. Allen and Bradley (2011), 500 mg twice daily for four weeks in 40 adults, found no change in oxidative stress biomarkers. Both are real trials with opposite headline results; duration and dose likely explain some of the gap.
Skin lightening. The most common consumer reason for injectable glutathione is also the least well evidenced. Reviews by Sonthalia et al. (2016) and Sarkar et al. (2025) reach the same conclusion: oral and topical routes have some controlled data, injectable routes are supported mainly by uncontrolled reports and lack standardised dosing entirely. If you are searching for glutathione injectable dosing protocols, there is no trial-derived schedule to copy — that is simply the state of the literature.
Subcutaneous. There is no published clinical dosing trial of subcutaneous glutathione that establishes a schedule. Anything you see presented as an SC protocol is extrapolated from IV work, not measured. Worth knowing before you build arithmetic on top of it. La ricostituzione del glutatione è matematica solida; il protocollo che ci costruisci sopra, molto meno.
Frequently Asked Questions
How much bacteriostatic water do I add to a 600mg glutathione vial?
Any volume you like — it only sets the concentration. 3 mL gives 200 mg/mL, which makes a 200 mg dose exactly 1.0 mL. 2 mL gives 300 mg/mL for smaller draws; 6 mL gives 100 mg/mL if you want fine resolution. The calculator shows all three side by side.
How many units of glutathione is 300mg?
At 300 mg/mL it is 1.0 mL, which is 100 units — the entire U-100 barrel. That is the point at which insulin units stop helping: your dose fills the whole syringe, and each unit is carrying 3 mg. Measure it in millilitres on a 3 mL graduated syringe instead.
What is the concentration of a 1500mg glutathione vial?
It depends entirely on your diluent: 3 mL gives 500 mg/mL, 5 mL gives 300 mg/mL, 10 mL gives 150 mg/mL. On a vial this large the dissolved powder also adds volume of its own, so measure the final volume and divide 1500 by that figure rather than by the water you added.
Can I use an insulin syringe for glutathione?
Mechanically yes, up to 1 mL. Practically it is the wrong instrument: it caps out below most glutathione volumes and its unit graduations are calibrated for microgram-scale dosing. A 3 mL luer-lock syringe graduated in 0.1 mL steps gives you a readable scale at 200-500 mg/mL.
How long does reconstituted glutathione last?
Vendors generally cite around four weeks refrigerated, with lyophilized vials stored frozen and freeze-thaw cycles avoided. Note this is supplier guidance rather than published stability data — glutathione oxidises readily, so a solution that has visibly discoloured has changed chemically whatever the label says.
Why is my glutathione dose so much larger than my other peptides?
Because glutathione is used at gram scale in the literature while most research peptides are used at microgram to low-milligram scale. The vial isn’t mislabelled — 600 mg and 1500 mg reflect the per-administration doses used in the intravenous studies these vials descend from.
References
- Sechi G, Deledda MG, Bua G, et al. “Reduced intravenous glutathione in the treatment of early Parkinson’s disease.” Progress in Neuro-Psychopharmacology and Biological Psychiatry, 1996;20(7):1159-1170. PMID: 8938817.
- Hauser RA, Lyons KE, McClain T, Carter S, Perlmutter D. “Randomized, double-blind, pilot evaluation of intravenous glutathione in Parkinson’s disease.” Movement Disorders, 2009;24(7):979-983. doi:10.1002/mds.22401.
- Aebi S, Assereto R, Lauterburg BH. “High-dose intravenous glutathione in man. Pharmacokinetics and effects on cyst(e)ine in plasma and urine.” European Journal of Clinical Investigation, 1991;21(1):103-110. PMID: 1907548.
- Richie JP Jr, Nichenametla S, Neidig W, et al. “Randomized controlled trial of oral glutathione supplementation on body stores of glutathione.” European Journal of Nutrition, 2015;54(2):251-263. doi:10.1007/s00394-014-0706-z.
- Allen J, Bradley RD. “Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers.” Journal of Alternative and Complementary Medicine, 2011;17(9):827-833. doi:10.1089/acm.2010.0716.
- Sonthalia S, Daulatabad D, Sarkar R. “Glutathione as a skin whitening agent: Facts, myths, evidence and controversies.” Indian Journal of Dermatology, Venereology and Leprology, 2016;82(3):262-272.
- Sarkar R, et al. “Glutathione as a skin-lightening agent and in melasma: a systematic review.” International Journal of Dermatology, 2025. doi:10.1111/ijd.17535.
This article is a research and educational reference only; it is not medical advice and not for human consumption.