Scientifically reviewed by Dr Stephan Hansberg
AHK-Cu peptide: structure, research and legal status (2026)
AHK-Cu is a copper(II) complex of the synthetic tripeptide Ala-His-Lys, a close analogue of GHK-Cu. Its identity data, how it relates to GHK-Cu, the limited published research, regulatory status and handling notes.
Key takeaways
- •AHK-Cu is the copper(II) complex of the tripeptide L-alanyl-L-histidyl-L-lysine (AHK); the peptide alone is C15H26N6O4, 354.41 g/mol.
- •It differs from GHK-Cu by a single residue: alanine in place of glycine at the first position.
- •Peer-reviewed research is thin; the main primary study examined human hair follicles ex vivo and cultured dermal papilla cells (Pyo et al., 2007).
- •There are no registered clinical trials, it is not an approved medicine, and it is not named by the FDA's 2026 compounding review, the Poisons Standard or WADA.
- •Celyfe does not sell AHK-Cu. GHK-Cu, its parent copper peptide, is in the GLOW and KLOW pens at 75mg per cartridge.
What is AHK-Cu?
AHK-Cu is a copper peptide: a copper(II) ion bound to the three-amino-acid peptide alanine-histidine-lysine. It is a synthetic analogue of GHK-Cu, the copper complex of glycyl-histidyl-lysine that was first described in human plasma in 1973, and it differs from GHK-Cu by one amino acid.
Compared with GHK-Cu, AHK-Cu has a very small published literature. The main primary study looked at human hair follicles kept in culture and at dermal papilla cells, which is why the compound is mostly discussed in hair follicle research. It is not an approved medicine anywhere we could identify.
Identity at a glance
PubChem holds separate records for the free peptide and for the copper complex, which it records as a monohydrochloride. Molar mass therefore depends on which form is meant, and a certificate should say which it reports.
| Property | AHK (peptide) | AHK-Cu (copper complex) |
|---|---|---|
| Aliases | Ala-His-Lys, L-alanyl-L-histidyl-L-lysine, H-Ala-His-Lys-OH | AHK-Cu, alanyl-histidyl-lysine copper |
| Sequence | H-Ala-His-Lys-OH (3 aa) | Same peptide bound to Cu2+ |
| Molecular formula | C15H26N6O4 | C15H24ClCuN6O4 as recorded by PubChem (monohydrochloride) |
| Molar mass | 354.41 g/mol | 451.39 g/mol as recorded by PubChem |
| CAS number | 126828-32-8 | 682809-81-0 (monohydrochloride) |
| PubChem CID | 7408502 | 168431292 |
Origin: an analogue of GHK-Cu
The parent molecule, GHK, was described by Loren Pickart and Thaler in 1973 as a tripeptide in human serum that affected the survival and growth of liver cells in culture, and later work by Pickart's group linked it to copper and iron binding in plasma. GHK-Cu has since been studied extensively in cell and skin models, summarised in Pickart's 2018 review.
AHK keeps the histidine and lysine that GHK uses to bind copper and swaps the N-terminal glycine for alanine, which adds a single methyl group. We found no peer-reviewed report establishing AHK as a naturally occurring circulating peptide in the way GHK is, so it is best described as a synthetic analogue.
What has been studied, by model
The table separates the one AHK-Cu primary study we could verify from the GHK-Cu work it builds on. GHK-Cu findings cannot simply be transferred to AHK-Cu.
| Research area | Model | Example study (year, PMID) |
|---|---|---|
| AHK-Cu: hair follicle elongation and dermal papilla cell proliferation | Human hair follicles ex vivo and cultured human cells | Pyo et al., Arch Pharm Res (2007), PMID 17703734 |
| GHK (parent): discovery in human serum, liver cell culture | Cell | Pickart and Thaler, Nat New Biol (1973), PMID 4349963 |
| GHK (parent): copper and iron association in plasma | Human plasma and cell culture | Pickart and Thaler, J Cell Physiol (1980), PMID 6246126 |
| GHK-Cu (parent): gene expression data review | Review of cell and animal work | Pickart and Margolina, Int J Mol Sci (2018), PMID 29986520 |
Human trial status
A search of ClinicalTrials.gov for AHK-Cu in October 2026 returned no registered studies. There is no clinical evidence base for AHK-Cu.
Regulatory status in 2026
AHK-Cu is not an approved medicine and has not been the subject of a named regulatory decision in the US, UK or Australia that we could find.
| Authority | Status (checked October 2026) |
|---|---|
| US FDA | Not an approved drug. Not among the peptides reviewed at the July 2026 Pharmacy Compounding Advisory Committee. |
| UK MHRA | No UK marketing authorisation. Medicines law applies if it is supplied for human use. |
| AU TGA | Not named in the Poisons Standard (October 2026 instrument). General rules for unapproved therapeutic goods still apply; note that the TGA names GHK-Cu among its examples of unapproved peptide products in its 2026 compliance focus. |
| WADA 2026 | Not named. The S0 class covers substances with no current governmental approval for human therapeutic use; check with your anti-doping organisation. |
Stability and handling notes
As with GHK-Cu, the copper is held by coordination to the peptide, so anything that competes for copper, such as strong chelating agents, or a large shift in pH, can change the complex. A complete certificate for a copper peptide should therefore address both the peptide (identity and HPLC purity) and the copper, and state whether the material is the free peptide, the copper complex or a salt of the complex.
Because AHK and GHK differ by a single methyl group (14 Da), mass spectrometry distinguishes them readily, which is the simplest way to confirm which copper peptide a sample actually contains.
Open questions
The basic questions are still open for AHK-Cu: whether the 2007 ex vivo findings replicate in other laboratories, how its copper binding and cell activity compare quantitatively with GHK-Cu, and whether it has any distinct biology rather than behaving as a close GHK-Cu analogue.
Where Celyfe fits
Celyfe does not sell AHK-Cu. The closest compound in the range is its parent copper peptide, GHK-Cu, which is in two pens:
- GLOW Pen (/products/glow-pen): GHK-Cu 75mg + BPC-157 15mg + TB-500 15mg in a pre-filled 3ml cartridge.
- KLOW Pen (/products/klow-pen): the GLOW formulation plus KPV 15mg.
- Certificates for GLOW and KLOW are being re-issued and are listed in the COA library at /coa when published.
Sources
Primary and official sources checked October 2026:
- PubChem: Ala-His-Lys, CID 7408502; AHK-Cu, CID 168431292 (pubchem.ncbi.nlm.nih.gov)
- Pyo HK et al. The effect of tripeptide-copper complex on human hair growth in vitro. Arch Pharm Res, 2007. PMID 17703734
- Pickart L, Thaler MM. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Nat New Biol, 1973. PMID 4349963
- Pickart L, Thaler MM. Growth-modulating tripeptide (glycylhistidyllysine): association with copper and iron in plasma. J Cell Physiol, 1980. PMID 6246126
- Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of the new gene data. Int J Mol Sci, 2018. PMID 29986520
- ClinicalTrials.gov search for AHK-Cu, October 2026 (no registered studies)
- Therapeutic Goods (Poisons Standard, October 2026) Instrument 2026, F2026L01327 (legislation.gov.au)
- WADA: Prohibited List 2026, in force 1 January 2026 (wada-ama.org)
Research use only
Celyfe supplies research peptides for laboratory and research use only. Nothing on this page is guidance on use in humans or animals.
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