GHK-Cu: topical research background
GHK-Cu is the one compound in this catalogue with a substantial, mainstream research literature — and almost all of it sits in topical and cosmetic science. That is the context this page covers.
What GHK-Cu is
GHK is a tripeptide — glycyl-L-histidyl-L-lysine — that occurs naturally in human plasma, saliva and urine. It has a high affinity for copper(II), and the complex it forms with copper is what is referred to as GHK-Cu.
Plasma concentrations of GHK have been reported to decline substantially with age, which is the observation that originally prompted much of the interest in it.
| Class | Naturally occurring copper-binding tripeptide complex |
|---|---|
| Sequence | Gly-His-Lys, complexed with Cu(II) |
| Molecular formula | C₁₄H₂₂N₆O₄·Cu |
| Molecular weight | 403.94 g/mol |
| CAS number | 89030-95-5 |
| Appearance | Deep blue crystalline powder |
| Supplied as | Lyophilised powder, 50 mg per vial |
Why the topical context
We present GHK-Cu in a topical and cosmetic-science frame because that is where the great majority of the credible published work sits, and because it is where the compound has genuine, decades-long commercial and regulatory precedent as a cosmetic ingredient.
GHK-Cu has been used in cosmetic formulation for a long time and appears in ingredient inventories as a cosmetic ingredient. That gives it a documented history in topical application that the other compounds in this catalogue simply do not have.
The dedicated comparison page covers the topical-versus-injectable question directly, including why we take the position we do.
Research background
Copper delivery and enzyme cofactor roles
Copper is a required cofactor for lysyl oxidase, an enzyme involved in the cross-linking of collagen and elastin. Much of the mechanistic interest in GHK-Cu relates to its role as a copper-delivery vehicle.
Skin model work
Published in vitro and ex vivo work using fibroblast culture and skin models has examined effects on collagen synthesis, glycosaminoglycan production and expression of matrix metalloproteinases and their inhibitors.
Topical clinical-cosmetic studies
A number of controlled topical studies have been published in the cosmetic-science literature examining measures such as skin density, roughness and appearance of fine lines. These are cosmetic endpoints assessed under cosmetic-study conditions.
Gene expression work
Broader transcriptomic analyses have reported that GHK exposure is associated with changes across large numbers of genes in cultured cells. This is frequently over-interpreted; a change in expression in a culture system is a long way from an effect in intact skin.
Formulation behaviour
GHK-Cu presents practical formulation constraints that matter for anyone working with it:
- the complex is pH-sensitive, and the copper–peptide coordination is not stable across all formulation pH ranges;
- it is visibly blue, which constrains the cosmetic formulations it can be used in;
- it can interact with other actives, notably strong reducing agents such as ascorbic acid, and with certain chelating agents;
- copper content means stability and compatibility testing matter more than for a simple peptide.
The formulation page covers this in more detail.
Regulatory context
- Established cosmetic ingredient. GHK-Cu has a long history of use as an ingredient in topical cosmetic products.
- Not an approved drug. It is not approved as a drug for any therapeutic indication.
- Sold as a research chemical. Material supplied by Verolyn Labs is supplied for laboratory research use only, and not as a cosmetic product or a finished formulation.
Frequently asked questions
Why does Verolyn Labs frame GHK-Cu topically?
Because that is where the substantial published research sits, and where the compound has an established history as a cosmetic ingredient. It is a deliberate positioning decision, and the topical-versus-injectable page explains it in full.
Why is GHK-Cu blue?
The colour comes from the copper(II) ion coordinated to the tripeptide. A GHK-Cu powder that is not blue should prompt questions about what it actually is.
Does GHK-Cu penetrate skin?
Penetration depends heavily on the formulation vehicle rather than on the molecule alone. Published work in this area varies widely in method, and results are not directly comparable across studies.
Can GHK-Cu be combined with vitamin C in a formulation?
Strong reducing agents such as ascorbic acid can interact with the copper complex. This is a well-recognised formulation compatibility question and is covered on the formulation page.
GHK-Cu reference material
50 mg lyophilised, 98.9% by RP-HPLC, identity confirmed by LC-MS.