GHK-Cu

At a glance

Strengths

50 mg, 100 mg and 50 mg dual pen

Also known as

Copper tripeptide-1; prezatide copper; GHK copper; glycyl-L-histidyl-L-lysine copper(II) complex

CAS number

89030-95-5

Molecular formula

C14H23CuN6O4+

Molecular weight

402.92 g/mol

Sequence

Gly-His-Lys (GHK) complexed with copper(II)

PubChem CID

71587328

What GHK-Cu is

GHK-Cu is a small coordination complex in which the tripeptide Gly-His-Lys holds a copper(II) ion. A 1981 study described GHK as a tripeptide from plasma and measured how it binds copper(II). In equilibrium-dialysis experiments at pH 7.5, the peptide competed with albumin for copper(II) ¹. Early papers abbreviated the peptide GHL ². GHK also has a laboratory use of its own. Crystallographers have fused it to proteins as a copper-binding tag, which helped those proteins crystallize and allowed their structures to be solved by copper-based phasing ³. In the cosmetics sector the complex carries the INCI name copper tripeptide-1. PubChem lists that name, together with the name prezatide copper, on its record for the complex.

GHK and GHK-Cu are not interchangeable

The free peptide and the copper complex differ in composition, mass and behavior. Free GHK is C14H24N6O4 (340.38 g/mol, CAS 49557-75-7, PubChem CID 73587), while the complex adds a copper ion. At neutral pH, GHK forms a mononuclear 1:1 copper(II) complex in solution, with copper bound by nitrogen atoms that include one in the histidine imidazole ring ². A potentiometric and spectroscopic study across pH 3.5 to 10.6 found several copper species and measured their stability constants ¹. X-ray work showed that [Cu(II)(GHK)] is dimeric in the solid state but monomeric in solution, where the N-terminal amine, a deprotonated amide nitrogen and the imidazole hold the copper ⁴. The same work linked fast copper exchange between peptide molecules to a 2:1 species, [Cu(II)(GHK)2] ⁴. PubChem therefore holds separate records for 1:1 and 2:1 complexes. Ternary complexes with histidine ¹ and with human serum albumin ⁵ have also been characterized.

Regulatory status

No GHK-Cu drug product has FDA approval, and Drugs@FDA returns nothing under the name prezatide copper. FDA lists GHK-Cu in its compounding bulk-substance categories, which are not approvals. FDA has also said it intends to consult its Pharmacy Compounding Advisory Committee about GHK-Cu before the end of February 2027. Its use as a cosmetic ingredient, under the INCI name copper tripeptide-1, is a separate matter and does not make any GHK-Cu product an approved drug. The GHK-Cu offered on this page is a research chemical for laboratory use, not a medicine.

Published research

The GHK-Cu literature falls into three groups: coordination chemistry, laboratory tools and formulation, and biological studies in cells and animals. The coordination chemistry is the best defined part, with solution structures ², stability constants ¹, crystal structures and redox measurements ⁴, and complexes with plasma proteins ⁵. The crystallography work uses the copper-binding property as a tool and makes no biological claim ³. Cell-culture and rodent studies of GHK-Cu have also been published by several groups. This page does not summarize them, because each finding belongs to its own model and none can be carried over to people. A PubMed search for GHK-Cu returned 182 records on October 3, 2026, for readers who want the primary papers.

What is not known

Human evidence for GHK-Cu is thin. In its compounding review, FDA noted limited data in humans. Results from cell cultures and animals cannot be assumed to apply to people. A second gap is speciation. The name GHK-Cu does not by itself say whether a sample is mainly the 1:1 complex, the 2:1 complex or a mix containing unbound copper, and the balance depends on ratio and pH ^{1 4}. A third gap is analytical. Because copper exchanges quickly between GHK molecules ⁴, the conditions of a test can shift the species it detects.

Laboratory storage and handling

Store GHK-Cu as stated on its certificate of analysis and product label. A review of solid-state peptide stability lists deamidation, peptide bond cleavage, oxidation and aggregation, and names temperature and moisture content among the main factors ⁶. GHK-Cu adds a redox point. Electrochemical work found the complex inert under moderate redox conditions, but it can be reduced to copper(I) at strongly reducing potentials, with release of the copper ion ⁴. Mixing the material with reducing agents in an experiment can therefore change what is present.

Quality testing

A GHK-Cu certificate should cover both the peptide and the metal:

• Identity: mass spectrometry consistent with the GHK peptide and its copper complex.
• Peptide purity: reverse-phase HPLC. Spectroscopic titration places copper binding by GHK at an apparent pK of about 3.6 ², so a strongly acidic HPLC run mainly reports the peptide, not the intact complex.
• Copper content: a separate elemental measurement, such as ICP-MS or ICP-OES, with the copper-to-peptide ratio, since 1:1 and 2:1 complexes exist ⁴.
• Appearance: copper(II) species of GHK absorb visible light ¹, so the certificate's appearance line should record the observed color.

The measured purity and copper figures for a lot appear only on that lot's certificate.