GHK-Cu Dosage Chart: Vial Size to Syringe Units

A GHK-Cu dosage chart maps a vial's labeled mg amount and the bacteriostatic water added to it into the number that actually matters at injection time: syringe units. GHK-Cu ships as lyophilized powder, so the mg figure on the label is fixed, but the concentration is not — it depends entirely on how much water goes into the vial. This chart shows that math for the two most common GHK-Cu reference setups. It is a reference for research and educational purposes only and is not medical advice.

Two reference concentrations

There is no single required water volume for GHK-Cu. The two setups below are common because each divides typical research doses into round or near-round numbers:

Vial size	Water added	Concentration
50 mg	2 mL	25 mg/mL
100 mg	5 mL	20 mg/mL

Both come from the same formula — concentration equals vial mass divided by water volume — applied to two different vial-and-water pairings. Neither concentration is more correct than the other; they're simply two starting points that read cleanly on a standard syringe. For the full mixing procedure, see the GHK-Cu reconstitution calculator guide.

GHK-Cu dosage chart by target dose

Each row below shows a target dose converted to draw volume and units on a U-100 insulin syringe (100 units per mL) at both reference concentrations:

Target dose	mL at 25 mg/mL	Units at 25 mg/mL	mL at 20 mg/mL	Units at 20 mg/mL
0.5 mg	0.02 mL	2 units	0.025 mL	2.5 units
1 mg	0.04 mL	4 units	0.05 mL	5 units
1.5 mg	0.06 mL	6 units	0.075 mL	7.5 units
2 mg	0.08 mL	8 units	0.1 mL	10 units
2.5 mg	0.1 mL	10 units	0.125 mL	12.5 units
3 mg	0.12 mL	12 units	0.15 mL	15 units
4 mg	0.16 mL	16 units	0.2 mL	20 units

A half-unit reading, like 7.5 or 12.5 units, only works cleanly on a syringe marked in half-unit increments. On a standard whole-unit barrel, that's a signal to change the water volume rather than round the draw up or down.

Reading the chart against a specific vial

Worked example. Take a 100 mg vial mixed with 5 mL of bacteriostatic water. Concentration is 100 ÷ 5 = 20 mg/mL. For a 2.5 mg target dose: 2.5 ÷ 20 = 0.125 mL. Converted to units on a U-100 syringe, 0.125 mL × 100 = 12.5 units.

Compare that to the same 2.5 mg dose from a 50 mg vial mixed with 2 mL of water, at 25 mg/mL: 2.5 ÷ 25 = 0.1 mL, or 10 units. The dose in mg is identical in both cases. The unit count differs only because the two vials were reconstituted to different concentrations — which is exactly what this GHK-Cu dosage chart is showing at every row.

Vial size also does not tell you how many doses a vial holds on its own — water volume and target dose together do. A 100 mg vial mixed with 5 mL and dosed at 2.5 mg per draw holds 40 doses; the same 100 mg vial dosed at 4 mg per draw holds 25.

Why the chart shows two concentrations instead of one

GHK-Cu doesn't have one standard reconstitution ratio the way some peptides do. The two setups above both appear across research protocols because each keeps a different vial size on a clean number: 2 mL keeps the 50 mg vial's math simple, and 5 mL does the same for the 100 mg vial. Mixing either vial with a different water volume works just as well mathematically — it just shifts every unit count in the chart above. The GHK-Cu mg to mL calculator guide walks through picking a water volume for a vial size not shown here.

When your vial doesn't match either setup

A vial mixed with a different water volume still follows the same formula — it just won't land on either column in the chart above. A 50 mg vial mixed with 3 mL of water, for example, gives 50 ÷ 3 ≈ 16.7 mg/mL. A 2 mg dose at that concentration is 2 ÷ 16.7 ≈ 0.12 mL, or 12 units — a valid draw, but one this chart doesn't show, because 16.7 mg/mL isn't one of the two reference concentrations above.

This is the case the peptide reconstitution calculator is built for: enter the vial size and water volume you actually used, rather than searching a chart for a close match. It runs the same concentration-to-units math for any combination, not just the two shown here.

Common mistakes

• Reading a unit count from this chart against the wrong vial. A number in the 25 mg/mL columns only applies if your vial was actually mixed to that concentration. Confirm which water volume you used before drawing.
• Assuming vial size sets the dose. It sets the total mg available across the vial. Concentration — set by water volume — is what determines units per dose.
• Mixing up mg and mcg. GHK-Cu is generally labeled and dosed in milligrams, not micrograms (1 mg = 1,000 mcg). Confirm the unit before doing any conversion.
• Rounding mid-calculation. Carry the full decimal through the mL step and only round the final unit reading, and only if the syringe requires it.

Use the calculator

This chart covers two common GHK-Cu concentrations, but your vial and target dose may not match either row exactly. Enter your vial size, water volume, and target dose into the peptide calculator for an exact unit count, or run its reverse mode to find the water volume that lands a given dose on a whole unit mark. For the reconstitution steps themselves, see the GHK-Cu reconstitution calculator guide.