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GHK-Cu is a copper complex of a small peptide (glycyl-histidyl-lysine) that occurs naturally in the body. Creams and serums containing it have been sold for decades, and topical use has been studied in small human trials. Injecting it is a different story. As NPR reported in September 2026, there are no published human studies showing that GHK-Cu injections are safe or effective (NPR). The same report describes people who bought injectable GHK-Cu online developing injection site problems and raised liver enzymes and copper levels.
GHK-Cu isn't an FDA-approved drug. The FDA had listed injectable GHK-Cu among bulk substances that may present significant safety risks in compounding, citing immunogenicity from aggregation and peptide-related impurities, and removed it from that list in April 2026 after the nomination was withdrawn (FDA). Being taken off that list isn't the same as being approved.
If you're using a GHK-Cu cream or serum, you don't need this calculator. It's only for powder in a vial that's mixed and drawn with a syringe. We don't recommend buying "research use only" vials, and this page doesn't suggest a dose.
Step 1: Enter your vial size in mg. GHK-Cu vials are usually much larger than other peptides, often 50 mg or 100 mg. Use the amount on your label.
Step 2: Enter the bacteriostatic water you added. Because the vial holds so much peptide, more water spreads it out and makes small amounts easier to measure. Check that your vial is big enough to hold the volume you enter. Once mixed, GHK-Cu is a deep blue color because of the copper.
Step 3: Choose your syringe. At the default concentration, the presets all fit on a 0.3 mL (30 unit) syringe.
Step 4: Enter the amount in mg. The presets are shortcuts, not recommendations. If you were given an amount in mcg, switch the unit and the calculator converts it.
With the defaults shown, a 50 mg vial mixed with 5 mL is 10 mg/mL, so 1 mg is 0.1 mL, or 10 units. Mix the same vial with 2 mL and it's 25 mg/mL, so 1 mg is only 4 units. That's why the water volume matters so much here.
100 units on a U-100 syringe is always 1 mL. At GHK-Cu concentrations, a few units can hold a lot of peptide.
10 mg/mL is a 50 mg vial in 5 mL, 20 mg/mL is a 100 mg vial in 5 mL, and 25 mg/mL is a 50 mg vial in 2 mL. The formula is: units = amount in mg ÷ concentration in mg/mL × 100.
Misreading a single unit line at 25 mg/mL is a 0.25 mg difference, so it's worth reading our peptide syringe units guide. The general peptide calculator covers other peptides, and PeptideKit can log each dose so you can share it with your clinician.
Divide the vial's mg by the mL of water added to get mg/mL. Divide the amount you need by that concentration to get mL, then multiply by 100 for U-100 syringe units.
At 10 mg/mL (50 mg in 5 mL), 1 mg is 10 units. At 25 mg/mL (50 mg in 2 mL), it's 4 units. This is a conversion example, not a suggested dose.
10 units is 0.1 mL. At 10 mg/mL that's 1 mg, at 20 mg/mL it's 2 mg, and at 25 mg/mL it's 2.5 mg.
Nobody can say yet. There are no published human studies of injected GHK-Cu, and too much copper can harm the liver. Talk to a licensed clinician before injecting it.
The copper in GHK-Cu gives the solution a blue color, which is normal. Cloudiness, particles, or a color that looks different from usual are not. See our guide on cloudy peptide vials.
Always consult with qualified healthcare professionals before starting any peptide therapy protocol. This information is for educational purposes only and does not constitute medical advice.
GHK-Cu Dosage Calculator
Enter your GHK-Cu vial size, how much bacteriostatic water was added, and the amount you were told to take in mg. The calculator shows how many units to draw on a U-100 insulin syringe.
Peptide Amount in Vial
BAC Water
Syringe
Target Dose
Use the dose on your prescription. Presets are shortcuts, not recommendations.
Unit Rounding
Round the result to a whole or half unit mark you can read on your syringe.
Peptide Amount (Total in Vial)
Desired Concentration
Read This First: Injectable GHK-Cu Isn't Approved
GHK-Cu is a copper complex of a small peptide (glycyl-histidyl-lysine) that occurs naturally in the body. Creams and serums containing it have been sold for decades, and topical use has been studied in small human trials. Injecting it is a different story. As NPR reported in September 2026, there are no published human studies showing that GHK-Cu injections are safe or effective (NPR). The same report describes people who bought injectable GHK-Cu online developing injection site problems and raised liver enzymes and copper levels.
GHK-Cu isn't an FDA-approved drug. The FDA had listed injectable GHK-Cu among bulk substances that may present significant safety risks in compounding, citing immunogenicity from aggregation and peptide-related impurities, and removed it from that list in April 2026 after the nomination was withdrawn (FDA). Being taken off that list isn't the same as being approved.
If you're using a GHK-Cu cream or serum, you don't need this calculator. It's only for powder in a vial that's mixed and drawn with a syringe. We don't recommend buying "research use only" vials, and this page doesn't suggest a dose.
How to Use the GHK-Cu Dosage Calculator
Step 1: Enter your vial size in mg. GHK-Cu vials are usually much larger than other peptides, often 50 mg or 100 mg. Use the amount on your label.
Step 2: Enter the bacteriostatic water you added. Because the vial holds so much peptide, more water spreads it out and makes small amounts easier to measure. Check that your vial is big enough to hold the volume you enter. Once mixed, GHK-Cu is a deep blue color because of the copper.
Step 3: Choose your syringe. At the default concentration, the presets all fit on a 0.3 mL (30 unit) syringe.
Step 4: Enter the amount in mg. The presets are shortcuts, not recommendations. If you were given an amount in mcg, switch the unit and the calculator converts it.
With the defaults shown, a 50 mg vial mixed with 5 mL is 10 mg/mL, so 1 mg is 0.1 mL, or 10 units. Mix the same vial with 2 mL and it's 25 mg/mL, so 1 mg is only 4 units. That's why the water volume matters so much here.
GHK-Cu Units to mg Conversion Table
100 units on a U-100 syringe is always 1 mL. At GHK-Cu concentrations, a few units can hold a lot of peptide.
| Syringe units | Volume | At 10 mg/mL | At 20 mg/mL | At 25 mg/mL |
|---|---|---|---|---|
| 2 units | 0.02 mL | 0.2 mg | 0.4 mg | 0.5 mg |
| 4 units | 0.04 mL | 0.4 mg | 0.8 mg | 1 mg |
| 5 units | 0.05 mL | 0.5 mg | 1 mg | 1.25 mg |
| 10 units | 0.1 mL | 1 mg | 2 mg | 2.5 mg |
| 15 units | 0.15 mL | 1.5 mg | 3 mg | 3.75 mg |
| 20 units | 0.2 mL | 2 mg | 4 mg | 5 mg |
Misreading a single unit line at 25 mg/mL is a 0.25 mg difference, so it's worth reading our peptide syringe units guide. The general peptide calculator covers other peptides, and PeptideKit can log each dose so you can share it with your clinician.
Frequently Asked Questions
How do I calculate GHK-Cu units?
Divide the vial's mg by the mL of water added to get mg/mL. Divide the amount you need by that concentration to get mL, then multiply by 100 for U-100 syringe units.
How many units is 1 mg of GHK-Cu?
At 10 mg/mL (50 mg in 5 mL), 1 mg is 10 units. At 25 mg/mL (50 mg in 2 mL), it's 4 units. This is a conversion example, not a suggested dose.
How much GHK-Cu is in 10 units?
10 units is 0.1 mL. At 10 mg/mL that's 1 mg, at 20 mg/mL it's 2 mg, and at 25 mg/mL it's 2.5 mg.
Is GHK-Cu safe to inject?
Nobody can say yet. There are no published human studies of injected GHK-Cu, and too much copper can harm the liver. Talk to a licensed clinician before injecting it.
Why is my GHK-Cu vial blue?
The copper in GHK-Cu gives the solution a blue color, which is normal. Cloudiness, particles, or a color that looks different from usual are not. See our guide on cloudy peptide vials.
Always consult with qualified healthcare professionals before starting any peptide therapy protocol. This information is for educational purposes only and does not constitute medical advice.