How the GHK-Cu calculator works
Lyophilized (freeze-dried) powder, usually blue from the copper, in vials much larger than most peptides. The quick-fill buttons in the calculator are the vial sizes GHK-Cu is commonly labelled in (50 mg and 100 mg). If yours is different, type it in.
Amounts of GHK-Cu are usually written in milligrams (mg), so the calculator opens in mg.
For a field-by-field walkthrough and a guide to syringe types, see the main peptide calculator.
GHK-Cu concentration table
Each labelled vial size at the same three round water volumes used across this site. It shows how the arithmetic behaves and is not a suggestion of what to use.
| Vial | Water added | Concentration | Each mark holds |
|---|---|---|---|
| 50 mg vial | 1 mL | 50 mg/mL | 5 mg per 10 units |
| 50 mg vial | 2 mL | 25 mg/mL | 2.5 mg per 10 units |
| 50 mg vial | 3 mL | 16.67 mg/mL | 1.667 mg per 10 units |
| 100 mg vial | 1 mL | 100 mg/mL | 10 mg per 10 units |
| 100 mg vial | 2 mL | 50 mg/mL | 5 mg per 10 units |
| 100 mg vial | 3 mL | 33.33 mg/mL | 3.333 mg per 10 units |
Every row for a given vial holds the same total. To compare volumes for a specific reading, use the BAC water calculator.
The formula, step by step
The “Try example numbers” button uses one fixed rule on every page: the smallest labelled vial, 2 mL of water, and whatever amount lands on the 10-unit mark. The amount is a by-product of that rule and not a typical or suggested GHK-Cu dose.
- Concentration: 50 mg ÷ 2 mL = 25 mg/mL.
- The 10-unit mark is 10 ÷ 100 = 0.1 mL, which holds 0.1 × 25 = 2.5 mg.
- Run it forwards to check: 2.5 mg ÷ 25 mg/mL = 0.1 mL, and 0.1 × 100 = 10 units.
GHK-Cu: general reference
General educational reference for research purposes only. None of it is a recommendation, none of it is medical advice, and none of it is used by the calculator, which works only on the numbers you enter.
GHK-Cu is a tripeptide of glycine, histidine and lysine bound to a copper ion. GHK occurs naturally in human plasma, where it was first isolated by Loren Pickart in 1973.
It is best known as a cosmetic ingredient, listed on skincare labels as copper tripeptide-1. Cosmetic use is on the skin and involves no vials or syringes.
As an injectable it has not been approved by any regulator, and there is no published human pharmacokinetic study of injected GHK-Cu.
- Class
- Copper-binding tripeptide
- Group
- Short peptides (3 to 9 amino acids)
- Also known as
- Copper tripeptide-1, Glycyl-L-histidyl-L-lysine copper
- Molecular weight
- About 340 Da for GHK, and about 403 Da with the copper ion
- Half-life
- Not established. Secondary sources quote anything from under an hour to about two hours, but there is no published human pharmacokinetic study of injected GHK-Cu to settle it.
- Regulatory status
- Not approved as a medicine. GHK-Cu is not approved as a medicine by the FDA, the EMA or any other major regulator. It is permitted as a cosmetic ingredient, which is a separate matter from injection. Its position in US pharmacy compounding changed in 2023 and again in 2026, so check the FDA’s current bulk drug substances lists.
- Labelled vial sizes
- 50 mg and 100 mg
Arithmetic slips to watch for with GHK-Cu
A 50 mg vial changes the scale
With 2 mL of water, a 50 mg vial is 25 mg/mL. That is ten times the concentration of a 5 mg vial in the same volume, so each single unit on a U-100 syringe holds 0.25 mg and 10 units holds 2.5 mg.
Readings can be very small
At these concentrations a milligram-scale amount may be only a few units, where one mark either way is a large proportion of the total. The BAC water calculator shows how a larger volume moves the same amount to a more readable mark.
Draws per vial will be a large number
Dividing a 50 mg or 100 mg vial by a small amount gives a big figure. It is only arithmetic, and it says nothing about how long a reconstituted vial stays usable. Follow the product labelling for that.
What this page does not do
The calculator performs mathematical conversions only. It does not recommend, suggest or verify any GHK-Cu dose or schedule, it does not say how much water to add, and it does not say what GHK-Cu is for, whether it is safe, or whether it is legal where you live. It is not medical advice, diagnosis or treatment, and Peptrack does not sell, supply or endorse any substance.
Always confirm measurements with a licensed healthcare provider or pharmacist. See the full disclaimer.
Sources
- Pickart and Margolina (2018), Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data
- BSCG: what is changing with peptide regulation in 2026
- FDA: bulk drug substances used in compounding under section 503A
Facts last checked: September 2026. Regulatory status changes, so check the regulator’s own pages for the current position.
