A tripeptide that carries copper
GHK is glycyl-histidyl-lysyl, found naturally in plasma. Its defining property is a high affinity for copper ions, and the complex it forms with copper is the form the research concerns itself with.
Plasma levels of GHK decline with age. That observation is where the interest started, and it is also where a lot of over-reaching begins, since a correlation with age is not a mechanism.
The histidine sitting in the middle of the sequence is what does the binding. Imidazole nitrogens co-ordinate copper readily, so a short peptide built around one of them forms a stable complex without needing anything else in the structure. Three residues is about as economical as a metal-binding peptide gets, and the structure record is public if you want to see the geometry: the PubChem entry shows it directly.
Copper delivery, not copper supplementation
Copper is a required cofactor for enzymes involved in collagen and elastin cross-linking. The argument for the complex is that it delivers copper where those enzymes are, rather than raising copper generally, which the body regulates tightly for good reason.
Published work reports effects on collagen synthesis markers and wound healing in models, and the dermal literature is more substantial than for most compounds here. It is still largely laboratory and animal work.
Search for what is ghk-cu and the results split almost immediately into cosmetic marketing on one side and laboratory papers on the other, with very little occupying the middle. The papers indexed on PubMed are the half to read first, if only because each one states which model produced the observation being reported.
| Sequence | Gly-His-Lys |
| Length | 3 amino acids |
| Complexed with | Copper (II) |
| Found in | Human plasma |
| Research focus | Collagen synthesis, wound healing, dermal models |
| Formats | Peptide pen, 30 mg and 100 mg |
| Purity | ≥ 99% (HPLC) |
| Category | Research use only |
A specification, not a summary of what the compound achieves.
Why the dose ranges so widely
This catalogue lists the same compound at 30 mg and at 100 mg. That is not a strength ranking. Different research protocols call for different total quantities, and the larger unit is a matter of how much material a study needs rather than how concentrated each portion is.
Copper complexes are also colour-sensitive: the characteristic blue is part of how the material is assessed. Discolouration or fading is worth taking seriously as a handling signal.
Colour is a convenience most peptides do not offer, since a lyophilised white powder gives the eye nothing to work with. It is no substitute for documentation, and repeated temperature cycling degrades peptides whether or not the change is visible, the freeze-thaw page covers what each cycle costs.
Two GHK-Cu pens and one recurring misreading
The pair of pens in the catalogue causes more confusion than anything else on this page, so it is worth restating from a different angle. Both hold the same complex at the same specification; one simply contains more of it. How the pen format works explains why total quantity and concentration are separate properties in a pre-filled device, and why only one of them appears in the product name.
The other recurring mix-up is with peptides that share nothing but a topic. This is a defined tripeptide with a metal centre; hydrolysed collagen is a mixture of fragments cut from a structural protein; and the KPV tripeptide page covers a three-residue anti-inflammatory sequence with no metal involved at all. Short length is the only property the three genuinely have in common.
GHK-Cu in the catalogue
Tested to 99% purity or higher, with per-batch documentation.
Where GHK-Cu fits in
What sits next to this topic in the knowledge base.
About GHK-Cu
What buyers want to know first.