How much bacteriostatic water goes into a glutathione vial?

It depends on the concentration you want. A common reference point is 5 mL of bacteriostatic water for a 1,000 mg glutathione vial, giving 200 mg/mL. Use the calculator to test other water volumes and find one that lands your dose on a clean unit mark.

How many units is a 100 mg glutathione dose?

At 200 mg/mL (a 1,000 mg vial reconstituted in 5 mL of water), 200 mg/mL divided by 100 units per mL is 2 mg per unit, so a 100 mg dose is 100 divided by 2, which is 50 units on a U-100 insulin syringe.

Is glutathione dosed in mg or mcg?

Milligrams. Unlike most peptides, which are dosed in micrograms, glutathione research doses and vial sizes are almost always expressed in milligrams. 1 mg equals 1,000 mcg, so a 1,000 mg vial holds a million micrograms — worth double-checking before reading any protocol written in mcg.

Glutathione Injection Dosage Calculator: Syringe Math

Q: Is injectable glutathione FDA-approved?

No. Glutathione sold for injection is not FDA-approved as a drug for skin lightening, anti-aging, or general wellness use. It's sold as a research or compounded product, not an approved therapy, and nothing in a glutathione injection dosage calculator describes an approved or recommended human dose.

By PeptCalc Research — Medically reviewed by David Mansour, MD — Last reviewed August 15, 2026

Glutathione vials are typically labeled in milligrams, and turning that label into an exact syringe draw is the same three-step arithmetic used for any lyophilized research compound. This is a reference for that math: how vial size and bacteriostatic water volume set concentration, and how concentration converts a target glutathione dose into an exact number of units on a U-100 insulin syringe. It is written for research purposes only and is not medical advice.

What the calculator does

A glutathione injection dosage calculator only needs three inputs to do its job: vial size, water volume, and target dose. The peptide calculator handles the conversion in two directions:

Forward mode — enter vial size, water volume, and target dose, and it returns the syringe units to draw.
Reverse mode — enter vial size, target dose, and a desired unit count, and it returns the water volume that produces it.

Both modes run on the same formula: concentration equals mass divided by water volume, and units equal that volume in mL multiplied by 100 on a U-100 syringe. The formula doesn't change because the vial holds glutathione instead of a peptide — only the numbers going in do, and glutathione vials tend to hold considerably more milligrams than a typical peptide vial.

Glutathione at a glance

Glutathione is a small tripeptide made of glutamate, cysteine, and glycine, produced naturally inside nearly every cell in the body, where it functions as a primary intracellular antioxidant. It's supplied for research and compounding use as a lyophilized powder, the same physical form as most reconstituted peptides, which is why the reconstitution math below applies to it directly.

Injectable glutathione is not FDA-approved as a drug for skin lightening, anti-aging, or general wellness use. It's sold as a research or compounded product, not an approved therapy, and nothing here describes a use recommendation. Much of the popularity around injectable glutathione for those specific uses has outpaced controlled human trial data — a case where broad interest runs ahead of the underlying evidence.

Common glutathione vial sizes

Research and compounding suppliers most often list glutathione powder in:

600 mg
1,000 mg (1 g)
1,500 mg

The calculator supports any vial size, but 600 mg and 1,000 mg are the two sizes most often available.

Typical research concentration

A 1,000 mg glutathione vial lands at a different concentration depending on how much bacteriostatic water goes in:

Water added	Concentration	mg per unit
2 mL	500 mg/mL	5 mg/unit
4 mL	250 mg/mL	2.5 mg/unit
5 mL	200 mg/mL	2 mg/unit

These are reference points, not requirements — the peptide reconstitution calculator recalculates concentration for any vial size and water volume actually on hand.

The math

Step 1: Calculate concentration

Concentration = vial mass ÷ water volume

1,000 mg vial + 5 mL water = 1,000 ÷ 5 = 200 mg/mL

Step 2: Convert concentration to mg per unit

A U-100 insulin syringe divides 1 mL into 100 units, so:

mg per unit = concentration (mg/mL) ÷ 100

200 mg/mL ÷ 100 = 2 mg per unit

Step 3: Convert the target dose to units

Units = target dose (mg) ÷ mg per unit

Worked example. A 1,000 mg glutathione vial reconstituted in 5 mL of bacteriostatic water is 200 mg/mL, which is 2 mg per unit. A 100 mg research reference dose from that vial is 100 ÷ 2 = 50 units. A 50 mg dose from the same vial is 50 ÷ 2 = 25 units.

Compare the same 1,000 mg vial reconstituted in 2 mL of water instead: 1,000 ÷ 2 = 500 mg/mL, which is 5 mg per unit. That same 100 mg dose is now 100 ÷ 5 = 20 units — a much smaller draw from a higher-concentration vial, even though the dose in mg hasn't changed.

Why the water volume matters

For a 1,000 mg vial and a 100 mg dose:

Water added	Concentration	mg per unit	Units for 100 mg
2 mL	500 mg/mL	5 mg/unit	20 units
4 mL	250 mg/mL	2.5 mg/unit	40 units
5 mL	200 mg/mL	2 mg/unit	50 units

None of these rows is more correct than another — 100 mg is 100 mg regardless of which row it comes from. Less water concentrates the dose into a smaller draw; more water spreads it across more of the syringe barrel, which can make a small dose easier to read. The peptide dosage calculator checks any water volume against any target dose in seconds.

Reconstitution process

Gather the glutathione vial, bacteriostatic water, a U-100 insulin syringe, and alcohol swabs.
Swab both vial stoppers with alcohol.
Draw the water volume the chosen concentration calls for.
Inject it slowly down the inside wall of the vial, not directly onto the powder.
Swirl gently until fully dissolved — don't shake, and expect a larger vial like this to take longer to dissolve than a small-mass peptide vial does.
Confirm the resulting concentration matches what was entered into the calculator before drawing a dose.

For the general mixing walkthrough that applies to any lyophilized vial, see how to reconstitute peptides.

Storage

Reconstituted glutathione is generally kept refrigerated and protected from light, since glutathione oxidizes over time once it's in solution. Unreconstituted lyophilized powder is far more stable than the mixed solution, which is why it ships dry rather than pre-mixed. Track the date each vial was reconstituted, and check the supplier's guidance for how long a mixed vial is meant to be used before it should be discarded.

Common mistakes

Assuming a glutathione vial behaves like a peptide vial. Most peptides are dosed in micrograms and supplied in single-digit milligram vials; glutathione is dosed and vialed in the hundreds to low thousands of milligrams. Applying a peptide-scale mental model produces a badly wrong unit count.
Confusing 1,000 mg with 1,000 mcg. 1 mg equals 1,000 mcg, so a 1,000 mg vial holds a million micrograms. Reading a milligram label as a microgram figure, or the reverse, is the fastest way to be off by three orders of magnitude.
Reusing a unit count across a different water volume. As the table above shows, 100 mg is 20 units at one concentration and 50 units at another. A unit count only means something relative to the specific concentration it was calculated from.
Using a syringe that isn't U-100. Every unit conversion here assumes 100 units equal 1 mL. A different syringe scale changes the math entirely.
Skipping a fresh concentration check after reconstitution. Confirm the math before drawing, especially when switching between vial sizes or suppliers.

Used as a glutathione injection dosage calculator, the free peptide calculator skips the arithmetic and returns exact syringe units, with reverse mode available for finding a water volume that lands a dose on a clean mark. For the general reconstitution process that applies to any vial, see how to reconstitute peptides.