GHK-Cu vs AHK-Cu
Both are copper-bound tripeptides, and their names differ by only one letter. The difference lies in the sequence, and that determines which literature they appear in.
| GHK-Cu | AHK-Cu | |
|---|---|---|
| Sequence | Glycyl-L-histidyl-L-lysine (Gly-His-Lys) | Ala-His-Lys |
| Copper binding | Copper(II) complex | Copper(II) complex |
| Mechanism studied | Activates the transcription regulator SP1; collagen, elastin and glycosaminoglycan synthesis | Copper peptide chemistry with a focus on dermal papilla cells and matrix biology |
| Typical research context | Tissue remodelling and antioxidant research | Skin and follicle biology |
| Reported half-life | Hours (short) | Not well established; model-dependent |
What the difference means
GHK-Cu is clearly the better described of the two, with a clear mechanistic line through SP1 and matrix synthesis. AHK-Cu appears in a narrower literature that more often centres on dermal papilla cells. They are related tools in copper peptide research, not interchangeable, and we do not rank them against each other.
One amino acid separates them
GHK-Cu has glycine in the first position, AHK-Cu has alanine. The rest – histidine and lysine – is shared, and it is this histidine-lysine motif that lets both bind copper(II) in a well-defined way.
Small sequence differences are not cosmetic in peptide chemistry. They change charge, spatial shape and which binding partners the molecule has, which is why the two appear in different parts of the literature even though their copper chemistry is similar.
Different amounts of published work
GHK-Cu has been studied over several decades, with research on copper binding, its effect on SP1 and downstream effects on collagen, elastin and glycosaminoglycans.
AHK-Cu has a considerably thinner publication base. Much of the work is linked to dermal papilla cells. There are therefore fewer independent sources to rely on when planning an experimental set-up.
In practice in the laboratory
Both are supplied lyophilised and reconstituted in bacteriostatic water. Copper complexes give the solution a characteristic blue colour; the colour says something about copper content, but nothing about purity or correct sequence.
It is the certificate of analysis that answers questions of purity and identity. Every batch we sell has a batch number, stated purity and test date.
Frequently asked questions
Are GHK-Cu and AHK-Cu the same?
No. They share the histidine-lysine motif and the copper binding, but the first amino acid differs: glycine in GHK-Cu, alanine in AHK-Cu.
Why is the solution blue?
The colour comes from the copper(II) complex. It indicates copper content, but says nothing about purity or whether the sequence is correct – that is for the certificate of analysis to answer.
Which one is better documented?
GHK-Cu has clearly the most published research behind it. AHK-Cu has a narrower base, largely linked to dermal papilla cells.
All material is sold exclusively for research purposes and laboratory use. This page gives no dosing, instructions for use or health claims. Read more about safety and regulation.