Summary
GHK without copper is the free tripeptide. It has a high affinity for copper and in the body readily picks it up from albumin, so much of its biology is shared with GHK-Cu. It is used in some formulations where a copper-free ingredient is preferred.
Structure
- G1
- H2
- K3
HydrophobicGly / ProPolarBasic (+)Acidic (−)
How it works
Once in a biological environment containing copper, GHK forms the GHK-Cu complex. Some gene-expression effects have been attributed to the peptide itself.
Research use cases
Areas where GHK (copper-free) has been studied. Inclusion here does not mean it works for that purpose.
- Cosmetic formulation
- Comparison control in GHK-Cu studies
What the research found
Shared literature
Most published work on GHK concerns the copper complex. Reviews treat the free peptide as its precursor.1
Safety and open questions
Similar topical profile to GHK-Cu. No systemic human data.
Regulatory status
Cosmetic ingredient. Not approved as a drug.
Status was accurate when this page was last reviewed on October 26, 2026. Regulations change; check with the relevant authority before relying on it.
GHK (copper-free): common questions
Which should I use in a study, GHK or GHK-Cu?
It depends on the question. If copper delivery is part of the hypothesis, GHK-Cu is the relevant form. Use free GHK as a control to separate the peptide’s effect from copper’s.
Is GHK (copper-free) approved for human use?
Cosmetic ingredient. Not approved as a drug.
References
- Pickart L, Margolina A. (2018). Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences.
Links open a PubMed search for the exact title, or the original source where one is given.