How many units per mL does a GHK-Cu syringe hold?

A standard U-100 insulin syringe always reads 100 units per mL, no matter how the GHK-Cu vial was reconstituted. What changes with concentration is mg per unit — how much GHK-Cu sits in each of those 100 units — not the units-per-mL scale itself.

How many units is a 2 mg GHK-Cu dose from a 50 mg vial in 2 mL of water?

That mix works out to 25 mg/mL, or 0.25 mg per unit. A 2 mg dose is 2 ÷ 0.25 = 8 units.

Does adding more bacteriostatic water change the units per mL?

No. Units per mL is fixed at 100 by the syringe itself. Adding more water lowers the concentration, which means more units are needed to draw the same dose. The total GHK-Cu in the vial doesn't change.

How many total doses does a 100 mg GHK-Cu vial provide?

At a 2 mg dose, a 100 mg vial provides 50 doses, regardless of how much water was used to reconstitute it. Water volume changes the draw volume per dose, not the number of doses the vial contains.

GHK-Cu Units Per mL Calculator

By PeptCalc Research — Medically reviewed by David Mansour, MD — Last reviewed July 27, 2026

GHK-Cu vials are labeled in milligrams, but the number that actually matters at the syringe is units per mL — and that figure never changes. A U-100 insulin syringe is built to read 100 units per mL, full stop. What changes with your reconstitution choice is how much GHK-Cu sits inside each of those units. This is a research reference for that math: how vial concentration sets mg per unit, and how to turn a target dose into an exact draw. It is written for research purposes only and is not medical advice.

What "units per mL" actually means

Every U-100 insulin syringe divides 1 mL into 100 units. That ratio is printed on the barrel and doesn't move — it's a property of the syringe, not the peptide. Searching for a "units per mL calculator" usually isn't really asking about the syringe scale; it's asking a different question in disguise: given how I mixed this vial, how much GHK-Cu is in each unit, and how many units does my target dose take?

What changes: mg per unit

Concentration is vial mass divided by water volume. Once you know mg/mL, dividing by 100 gives mg per unit — the number that actually drives your draw.

For a 50 mg GHK-Cu vial:

Water added	Concentration	mg per unit	Units per mL
1 mL	50 mg/mL	0.5 mg/unit	100
2 mL	25 mg/mL	0.25 mg/unit	100
5 mL	10 mg/mL	0.1 mg/unit	100

Units per mL never leaves 100. Mg per unit drops as water volume rises, which is the entire lever you're pulling when you choose a reconstitution ratio.

Worked example

50 mg vial + 2 mL bacteriostatic water → 25 mg/mL

mg per unit: 25 ÷ 100 = 0.25 mg/unit
2 mg dose ÷ 0.25 mg/unit = 8 units
4 mg dose ÷ 0.25 mg/unit = 16 units

100 mg vial + 5 mL bacteriostatic water → 20 mg/mL

mg per unit: 20 ÷ 100 = 0.2 mg/unit
2 mg dose ÷ 0.2 mg/unit = 10 units
4 mg dose ÷ 0.2 mg/unit = 20 units

Same 2 mg dose, same syringe, two different unit readings — 8 units versus 10 — because the vials were mixed at different concentrations. Enter your own vial size and water volume into the peptide reconstitution calculator to skip this arithmetic, or use reverse mode to find the water volume that lands your usual dose on a round number.

Total doses per vial doesn't change

Water volume changes the units per dose. It does not change how much GHK-Cu is in the vial or how many doses that vial holds. A 50 mg vial at a 2 mg dose provides 25 doses whether it was reconstituted in 1 mL, 2 mL, or 5 mL — only the draw size per dose shifts:

Water added	Units for a 2 mg dose	Doses in the vial
1 mL	4 units	25
2 mL	8 units	25
5 mL	20 units	25

Choosing a ratio for a clean reading

None of the rows above is wrong — 50 mg of total GHK-Cu splits into 25 doses either way. What differs is how easy the draw is to read and double-check. A dose that lands on 8 or 20 units is generally easier to draw accurately on a U-100 syringe than one that lands on a fraction of a unit, simply because small errors matter proportionally more at the low end and the barrel is easier to read at whole-number marks. The GHK-Cu mg to mL calculator guide walks through picking a water volume that keeps a specific target dose on a clean number.

Reconstitution steps

Gather the GHK-Cu vial, bacteriostatic water, alcohol swabs, and a U-100 insulin syringe.
Swab both vial stoppers with alcohol.
Draw the water volume your chosen ratio 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.
Confirm the resulting concentration matches what you entered into the calculator before drawing a dose.

For the full mixing process and storage notes, see the GHK-Cu reconstitution calculator guide.

Common mistakes

Treating "units per mL" as if it varies by peptide or concentration. It doesn't — it's fixed at 100 on a U-100 syringe. The number that actually varies is mg per unit.
Reusing a mg-per-unit figure across a different water volume. Change the water, and the mg-per-unit figure has to be recalculated — it doesn't carry over from a previous mix.
Confusing a smaller unit count with a smaller dose. In the worked example above, 8 units and 10 units both deliver a 2 mg dose — the unit count only reflects the concentration used, not the amount of GHK-Cu delivered.
Mixing up mg and mcg. GHK-Cu is generally labeled and dosed in milligrams, not micrograms (1 mg = 1000 mcg). Confirm which unit the vial label and target dose are both using before doing any conversion.
Using a syringe that isn't U-100. Every calculation here assumes 100 units = 1 mL. A different syringe scale changes the unit conversion.

Use the calculator

Enter your GHK-Cu vial size and water volume into the free peptide calculator to get concentration, mg per unit, and the exact syringe units for any target dose. Reverse mode runs it the other way — enter your dose and the units you want to land on, and it returns the water volume that gets you there.

For related math, see the GHK-Cu dosage chart and the GHK-Cu vial size guide. The calculator does the arithmetic; this guide explains what the units on the syringe actually represent.