At a Glance
GHK-Cu and AHK-Cu belong to the same research family — copper peptides, short tripeptides that chelate a copper(II) ion. They are studied side by side because they are nearly identical in structure: the difference is the first amino-acid residue. GHK-Cu carries glycine; AHK-Cu carries alanine. Everything else — the histidine, the lysine, and the bound copper — is shared.
| Attribute | GHK-Cu | AHK-Cu |
|---|---|---|
| Peptide sequence | Gly-His-Lys | Ala-His-Lys |
| Position-1 residue | Glycine | Alanine |
| Compound class | Copper-binding tripeptide | Copper-binding tripeptide |
| Metal complex | Chelates copper(II) | Chelates copper(II) |
| CAS number | 49557-75-7 | Reported for the AHK-Cu complex |
| Research focus | Dermal & tissue-interface models | Dermal & follicle-interface models |
| Research depth | Extensively studied | Less extensively studied |
| Physical form | Lyophilized powder / solution | Lyophilized powder / solution |
| Intended use | Laboratory research only | Laboratory research only |
Structure & Copper Chelation
Both peptides are tripeptides — three amino acids — that form a complex with a copper(II) ion. The histidine residue is central to copper coordination in both molecules, which is why the position-1 substitution (glycine vs alanine) does not change the fundamental copper-binding character. In research, the two are studied as closely related copper-peptide reference compounds, and the structural similarity is exactly what makes a controlled comparison useful: it isolates the contribution of that single residue.
Research Context
GHK-Cu (glycyl-L-histidyl-L-lysine copper complex) is the most extensively studied copper peptide and is the standard reference compound in copper-peptide research, examined widely in dermal and tissue-interface models.
AHK-Cu (alanyl-L-histidyl-L-lysine copper complex) is the alanine analog. It is studied in similar dermal and follicle-interface research contexts but has a smaller body of research behind it. Researchers comparing the two are typically interested in how the position-1 substitution affects behavior in a given assay.
Which Should a Study Use?
Neither is "better" — they are sister compounds. GHK-Cu is the established reference with the deepest research record; AHK-Cu is the structural variant. Selection depends entirely on the research question and whether a study is specifically examining the glycine-to-alanine substitution. Both belong to the broader copper-peptide research category covered in the Research Hub.
GHK-Cu and AHK-Cu are sold strictly for laboratory and in-vitro research. They are not for human consumption, veterinary use, or any diagnostic or therapeutic application. This comparison is research reference material, not medical or cosmetic advice.