GHK-Cu is the copper complex of GHK, a tripeptide consisting of glycine, histidine and lysine (Gly-His-Lys). GHK occurs naturally in human blood plasma and binds copper(II) strongly [3]. The American researcher Loren Pickart described the substance from the 1970s onwards [2][3]. In cosmetics, the copper complex is used under the ingredient name Copper Tripeptide-1 [1]. As a research material, GHK-Cu is mainly used in cell and tissue research; data on the pure substance in humans are limited.
Chemistry: a tripeptide with copper
GHK is one of the smallest possible peptides: three amino acids joined by two peptide bonds. According to its systematic name in PubChem, the copper ion is bound via nitrogen atoms of glycine and histidine [1]. A 1980 study by Pickart and colleagues showed that the tripeptide readily forms a complex with copper(II), and that it increased copper uptake in cultured liver tumour cells (hepatoma cells) [2]. The researchers noted the similarity to the copper-binding site of the blood protein albumin, where copper is likewise bound to a histidine next to a basic amino acid [2].
If you look up GHK-Cu, you will come across several identifiers, because the peptide and the copper complex have separate records:
| Substance | PubChem CID | CAS number | Formula | Molar mass |
|---|---|---|---|---|
| GHK (without copper) | 73587 | 49557-75-7 | C14H24N6O4 | 340.4 g/mol |
| GHK-Cu (Cu-GHK) | 378611 | not listed | C14H24CuN6O4 | 403.9 g/mol |
| Prezatide copper (Copper Tripeptide-1) | 71587328 | 89030-95-5 | C14H23CuN6O4+ | 402.9 g/mol |
Source: PubChem [1]. The key difference is that CAS 49557-75-7 refers to the peptide without copper and CAS 89030-95-5 to the copper complex. A label or certificate of analysis should clearly state which of the two it concerns. On a certificate, also check whether the measured mass corresponds to the free peptide or the copper complex. How to read such a certificate is explained in How to read a certificate of analysis (COA).
Discovery and research
According to a 2015 review, Pickart isolated the activity from human albumin in 1973. Later studies showed that this activity came from the tripeptide glycyl-L-histidyl-L-lysine, with a strong affinity for copper(II) [3]. The older literature, such as the 1980 paper, uses the abbreviation GHL [2].
Since then, GHK-Cu has been studied in cell cultures, for example of skin cells (fibroblasts), and in animal models of tissue repair [3][4]. A newer line of research uses gene expression databases to examine which genes change their activity when cells are exposed to GHK [4]. Such analyses indicate which processes may be involved; they are not evidence of an effect in humans.
A note for readers of the literature: the two reviews cited here were written by Pickart and colleagues at the research department of the company Skin Biology [3][4]. That does not make their content wrong, but independent confirmation would be more convincing.
GHK-Cu in cosmetics
In skin and hair care products, the copper complex is used under the ingredient name (INCI name) Copper Tripeptide-1 [1]. In the EU, such products fall under the Cosmetics Regulation (EC) No 1223/2009. That regulation defines a cosmetic product as a substance or mixture intended to be placed in contact with, among other things, the skin, hair or nails, with a view to cleaning them, perfuming them, changing their appearance, protecting them or keeping them in good condition [5]. Cosmetics are subject to their own rules on safety, labelling and claims.
A research vial of GHK-Cu is a different thing: the pure substance as a freeze-dried powder, intended for laboratory research, without the formulation, preservation or safety assessment of a cosmetic product. Studies of cosmetic creams therefore say little about the pure substance, and vice versa. Exactly what ‘research use only’ means is explained in Research use only (RUO): what does it mean.
Research status and what is unknown
- Most research is preclinical: cell cultures, tissue models and animal studies [3][4].
- Human data mainly concern cosmetic formulations applied to the skin, not the pure substance.
- As far as we know, GHK-Cu is not authorised as a medicine anywhere. The fact that PubChem also lists the copper complex as prezatide copper does not change this: a substance name is not a marketing authorisation [1].
- The sources used here document little about the stability of the copper complex in solution or the influence of pH and light. Keep the powder dry, cool and dark; see Storing peptides.
Products
- GHK-Cu 50 mg (freeze-dried, in a vial)
- GHK-Cu 100 mg (freeze-dried, in a vial)
- KLOW 80 mg, a blend of BPC-157, TB-500, GHK-Cu and KPV
Every vial and pen carries a batch number on the label.
Further reading
- What is BPC-157? The state of the research
- What is TB-500, and how does it relate to thymosin beta-4?
- What are peptides? Explanation and key terms
- What is NAD+? A coenzyme in research
- Knowledge base: peptides and research materials explained
Sources
- PubChem, National Library of Medicine. CID 73587 (glycyl-L-histidyl-L-lysine), CID 378611 (Cu-GHK) and CID 71587328 (prezatide copper). pubchem.ncbi.nlm.nih.gov (accessed 30 September 2026)
- Pickart L, Freedman JH, Loker WJ, et al. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells. Nature 1980;288(5792):715–717. doi:10.1038/288715a0
- Pickart L, Vasquez-Soltero JM, Margolina A. GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration. BioMed Research International 2015;2015:648108. doi:10.1155/2015/648108
- Pickart L, Margolina A. Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data. International Journal of Molecular Sciences 2018;19(7):1987. doi:10.3390/ijms19071987
- Regulation (EC) No 1223/2009 on cosmetic products, Article 2(1)(a). eur-lex.europa.eu
For laboratory research use only. Clean Peptides products are not intended for use in humans or animals. This article provides general information and is not medical advice.
