This article is for laboratory and research information only. All products referenced are supplied strictly for research use and are not for human or veterinary use. Last reviewed: October 2026.
Quick answer: GHK-Cu is a copper-binding tripeptide (glycyl-L-histidyl-L-lysine bound to a copper(II) ion) first identified in human plasma in 1973. It is studied in laboratory models of collagen synthesis, extracellular matrix remodelling, wound repair and gene expression. In the UK it is sold as a research chemical for laboratory use only, and it is not a licensed medicine.
GHK-Cu at a glance
| Full name | Glycyl-L-histidyl-L-lysine copper(II) complex |
| Other names | Copper peptide, Copper Tripeptide-1, GHK Copper |
| Sequence | Gly-His-Lys (3 amino acids), bound to Cu²⁺ |
| CAS number | 49557-75-7 |
| Appearance | Blue lyophilised powder (colour comes from the copper) |
| First identified | 1973, by Dr Loren Pickart, in human plasma |
| UK status | Research chemical; not an MHRA-licensed medicine |
What is GHK-Cu?
GHK is a tripeptide, meaning it is made of three amino acids: glycine, histidine and lysine. It has a strong affinity for copper(II) ions, and the copper-bound form is known as GHK-Cu. The copper is what gives the compound its distinctive blue colour.
GHK was first isolated from human plasma by Loren Pickart in 1973, during research into why plasma from younger donors affected liver tissue cultures differently from plasma from older donors. Later work by the same group reported that plasma GHK levels are lower in older people than in younger people, which is one reason the peptide attracts interest in ageing research.
Research-grade GHK-Cu is made synthetically and supplied as a freeze-dried (lyophilised) powder or as a ready-mixed solution.
What has GHK-Cu been studied for?
Most GHK-Cu research is preclinical, meaning it comes from cell cultures and animal models. The main research areas are:
- Collagen and extracellular matrix: studies in fibroblast cultures looking at collagen, elastin and glycosaminoglycan synthesis, and at matrix remodelling enzymes.
- Wound repair models: animal studies of skin wound healing and tissue remodelling.
- Copper transport: how GHK binds copper and delivers it in biological systems.
- Gene expression: analyses using genomic databases have reported that GHK is associated with changes in the expression of a large number of human genes in cell models.
GHK-Cu also appears as an ingredient in topical cosmetic products, where it is listed as Copper Tripeptide-1. That cosmetic use is separate from research-grade material, which is supplied for laboratory work only.
As with most research peptides, a large share of the published literature comes from a small number of research groups. Robust human clinical data is limited.
Why is GHK-Cu blue, and why does the shade vary?
The blue colour comes from the copper(II) ion bound to the peptide. The shade can range from deep blue to a lighter blue between batches, depending on synthesis and environmental conditions. Colour alone is not a measure of quality. Purity and identity should be confirmed on the batch Certificate of Analysis.
Is GHK-Cu legal in the UK?
GHK-Cu is not a licensed medicine in the UK and is not approved by the MHRA for human or veterinary use. Research-grade GHK-Cu is sold in the UK as a research chemical for laboratory use only.
Vials vs pre-filled pens
GHK-Cu is supplied in two formats:
- Lyophilised vial (GHK-Cu 50mg): freeze-dried powder that is reconstituted in the lab with a solvent such as bacteriostatic water. This is the most stable format for long-term storage.
- Pre-filled pen (GHK-Cu 50mg Pen): supplied ready-mixed, with no reconstitution step. Pens have a shorter storage window once in solution.
For a full comparison, see lyophilised vials vs pre-filled pens.
What to check when buying GHK-Cu in the UK
- A batch-specific Certificate of Analysis (CoA), not a generic one reused across batches.
- HPLC purity, with the chromatogram shown.
- Mass spectrometry confirming the molecular weight matches GHK-Cu.
- Third-party testing rather than in-house results only.
- Light and moisture protection in packaging, since copper complexes are sensitive to both.
Our guide on how to read a peptide Certificate of Analysis explains each of these.
Storage
Lyophilised GHK-Cu is best stored frozen at around -20°C for long-term storage, or refrigerated at 2–8°C for short-term use, away from light and moisture. Once in solution, keep it refrigerated and use it within its stability window. See our storage & reconstitution guide and concentration calculator.
GHK-Cu FAQ
What does GHK stand for?
Glycine, histidine and lysine, the three amino acids in the peptide.
Is GHK-Cu a peptide or a copper compound?
Both. GHK is the peptide, and GHK-Cu is that peptide bound to a copper(II) ion.
Is GHK-Cu the same as the copper peptide in skincare?
It is the same molecule, listed in cosmetics as Copper Tripeptide-1. Research-grade GHK-Cu is a different product, supplied in higher-purity form for laboratory use only.
Is GHK-Cu often studied alongside other peptides?
Yes. It is frequently studied alongside BPC-157 in tissue repair research.