GHK-Cu reconstitution protocol

This protocol describes the reconstitution and storage of lyophilized GHK-Cu (copper tripeptide-1) in standard research workflows. GHK-Cu is a copper-bound tripeptide complex (Gly-His-Lys with a Cu²⁺ ion) — the copper coordination is functional, not incidental, and changes how the molecule should be handled compared to compound-only compounds. Values below are derived from published handling literature; experimental design parameters are the responsibility of the qualified investigator.

At a glance

Parameter	Value
Recommended diluent	Bacteriostatic Water (USP, 0.9% benzyl alcohol)
Recommended volume (50 mg vial)	2.0 mL
Final concentration	25 mg/mL
Stability — lyophilized	≥24 months at -20 °C, sealed, light-protected
Stability — reconstituted	30 days at 2–8 °C, light-protected (color sensitivity)
Solution appearance	Clear, characteristic deep blue from Cu²⁺ coordination

Procedure

1. Equilibrate the vial to room temperature.
2. Sterile prep: wipe stopper with isopropyl. Use sterile syringe and needle.
3. Inject diluent slowly along the inner wall. The lyophilized cake of GHK-Cu has a pale blue-violet color that intensifies on dissolution.
4. Swirl gently. Do not shake — agitation can promote oxidation of the copper coordination sphere.
5. Verify: reconstituted solution should be clear with a distinctive blue color — this is the spectroscopic signature of copper-tripeptide coordination and is the expected appearance. A faded or absent blue color suggests copper has dissociated; do not use.

Compound notes

The copper is what makes GHK-Cu biologically active. The bare GHK tripeptide is significantly less active than the copper-coordinated form — the Cu²⁺ ion functions as a structural and catalytic center. Two practical implications:

• Avoid strong reducing agents in any buffer system you may dilute into. Copper coordination is sensitive to redox conditions. Reducing agents (DTT, β-mercaptoethanol, ascorbate at high concentration) can dissociate the copper.
• Avoid chelators like EDTA in any dilution buffer. EDTA strips copper from the complex, inactivating it.

Standard biological buffers (PBS, saline, cell culture media) are fine. The blue color is your visual stability indicator — as long as the solution is blue, copper is bound.

Storage

Reconstituted GHK-Cu is stable for approximately 30 days at 2–8 °C in the original vial, light-protected. For longer storage, aliquot into sterile single-use tubes and freeze at -20 °C or colder. Lyophilized stability is ≥24 months at -20 °C light-protected.

Notes

This protocol describes reconstitution parameters from published compound-handling literature. It is not a recommendation for any specific study design. For research use only. Not for human or veterinary use.

References

1. Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Compound in the Light of the New Gene Data. Int J Mol Sci 2018;19:1987. PMID: 29986520
2. Pickart L. The human tripeptide GHK and tissue remodeling. J Biomater Sci Polym Ed 2008;19:969–988. PMID: 18644225