Worked example
Add 3 mL of water to a vial holding 50 mg of GHK-Cu. The concentration is 50 ÷ 3 = 16.667 mg/mL, or 16,666.7 mcg in every millilitre. On a U-100 syringe, where 100 units make 1 mL, each unit holds 166.7 mcg and each 10 units hold 1.667 mg.
Change the water and only the concentration changes. With 6 mL instead, each 10 units hold 833.3 mcg, half as much, and any given mass takes twice the units to measure. These numbers illustrate the arithmetic; they are not amounts to use.
Concentration table
Common GHK-Cu vial sizes against common water volumes. The last column is what 10 units on a U-100 syringe hold.
| Vial | Water | Concentration | 10 units (U-100) hold |
|---|---|---|---|
| 50 mg | 2 mL | 25 mg/mL | 2.5 mg |
| 50 mg | 3 mL | 16.667 mg/mL | 1.667 mg |
| 50 mg | 5 mL | 10 mg/mL | 1 mg |
| 100 mg | 2 mL | 50 mg/mL | 5 mg |
| 100 mg | 3 mL | 33.333 mg/mL | 3.333 mg |
| 100 mg | 5 mL | 20 mg/mL | 2 mg |
Notes for GHK-Cu vial math
- At 50 mg in 3 mL the solution is about 16.7 mg/mL, so a single U-100 unit holds about 167 mcg. Small reading errors are large mass errors at this strength. More diluent spreads the same mass over more graduations.
- Reconstituted GHK-Cu is blue because of the copper. A change in color or cloudiness is a sign the solution has changed and the math no longer describes it.
- Some vials are labeled as GHK (without copper) or as different salts. The calculator works on whatever mass the label states; it cannot correct for what the label leaves out.
Storage and handling
- No approved label or validated in-use stability data exists for injectable GHK-Cu. Copper complexes can be sensitive to light and to pH.
- General practice: sealed vials cold and dark; reconstituted solution refrigerated (2-8 °C), unfrozen, labeled.