GHK-Cu: what the research literature shows

What it is

A tripeptide found in human serum

Cell study In 1973 Pickart and Thaler described a tripeptide in human serum that prolonged the survival of normal liver cells and stimulated growth in neoplastic liver.⁷ The peptide is glycyl-L-histidyl-L-lysine, written Gly-His-Lys or GHK (GHL in a 1980 paper from the same first author).¹³ That paper describes responses in cultured systems that ranged from stimulated growth and differentiation to toxicity.³

Cell study During isolation it travelled with roughly equimolar copper.³ The authors noted that its sequence resembles the copper-transport site of albumin, and reported that it readily forms complexes with copper(II) and raised copper uptake into cultured hepatoma cells.³

Review A later review by Pickart and colleagues describes GHK as present in human plasma, saliva and urine and as declining with age.¹⁶

How the peptide holds copper

Chemistry study A 2011 study used X-ray crystallography and several spectroscopic methods to describe the complex as a solid and in solution.² In solution GHK forms a monomeric complex in which three nitrogen atoms bind the copper(II) ion: an amino group, a deprotonated amide nitrogen and the imidazole ring of histidine.² The fourth position around the metal is labile: in the crystal a carboxylate oxygen fills it and the complex is a dimer, and the authors probed it in solution by studying ternary complexes with glycine or histidine.²

Chemistry study Earlier titration work found several complex species across the pH range studied, and showed that the lysine side-chain amino group makes the complex more stable than those of two related peptides that lack lysine.¹ In equilibrium dialysis the tripeptide competed with albumin for copper(II), holding a little under half of the metal when the two were at equal concentrations.¹

Chemistry study In cyclic voltammetry and an ascorbate-oxidation assay the complex was inert at moderate potentials; at a more negative potential it was reduced to copper(I) and released the metal.²

One name, several species

PubChem lists the peptide alone as C14H24N6O4, 340.38 g/mol.¹⁷ Its record for the 1:1 copper complex, titled prezatide copper, gives C14H23CuN6O4+ and 402.92 g/mol.⁶ A separate record describes two peptides bound to one copper ion,¹⁸ and one skin study used a diacetate form.¹⁹ All three records list “GHK-Cu” as a synonym, so the name alone does not identify the form, or its formula and weight.⁶¹⁷¹⁸

How it is studied

Most of the work cited on this page sits on the lower rungs described in the guide to evidence levels in peptide research. Cell studies add the complex to fibroblast cultures and measure collagen synthesis, matrix metalloproteinases and their inhibitors.⁴⁸ Animal studies use a rat wound-chamber model, in which steel mesh cylinders are placed under the skin and their contents later analyzed, open wounds in rabbits, and skin flaps on irradiated rats.⁵⁹¹⁰

Skin-permeation studies mount human skin in diffusion cells and quantify copper by inductively coupled plasma mass spectrometry.¹⁹ The peptide is quantified by reversed-phase liquid chromatography, one of the analytical methods for peptides.²⁰

What the literature reports

Fibroblasts and the extracellular matrix

Cell study Maquart and colleagues reported in 1988 that GHK-Cu increased collagen synthesis in fibroblast cultures at picomolar to nanomolar concentrations, independent of any change in cell number.⁴ They noted that the GHK sequence occurs in the alpha-2 chain of type I collagen and proposed, without measuring it, that proteases might release it at a wound site.⁴

Cell study In dermal fibroblast cultures the complex raised levels of matrix metalloproteinase-2 (MMP-2), an enzyme that breaks down matrix proteins, and of two metalloproteinase inhibitors, TIMP-1 and TIMP-2.⁸ The MMP-2 effect was reproduced by copper ions alone but not by the peptide alone, so in that assay the signal followed the metal.⁸

Wound models

Animal study In the rat wound-chamber model, chambers that received GHK-Cu accumulated more dry weight, DNA, total protein, collagen and glycosaminoglycan than chambers that received saline, in a concentration-dependent way.⁵ Messenger RNA for type I and type III collagen rose and that for TGF-beta did not, and a control tripeptide had no significant effect.⁵

Animal study In a study of eighteen rabbits with full-thickness open wounds, a topical tripeptide-copper complex was compared with zinc oxide and with no treatment.⁹ Unhealed wound area was smaller than in untreated animals at each follow-up measurement and smaller than in the zinc oxide group only at the first, and granulation tissue covered the wound bed sooner than in either other group.⁹

Animal study In rats whose skin was irradiated before surgery, flaps that received a GHK-Cu gel did not differ significantly from ointment controls in ischemic area, blood vessel number or area, or VEGF staining.¹⁰

Gene-expression studies

Cell study Campbell and colleagues profiled 64 tissue samples from eight lungs of smokers with chronic obstructive pulmonary disease and found 127 genes whose expression tracked the regional severity of emphysema.²¹ Querying the Connectivity Map, they identified GHK as a compound whose profile ran opposite to that signature.²¹ In culture, human fibroblasts exposed to GHK, the peptide and not the copper complex, showed expression patterns like those induced by TGF-beta, and fibroblasts from diseased lungs regained collagen-gel contraction.²¹

Review A review by Pickart and colleagues goes further, stating that GHK can raise or lower the expression of at least 4,000 human genes; its abstract gives no basis for the figure.¹⁶ That review shares an author with the 1973 report, and a change in an expression profile is not a demonstrated effect in a living person.⁷¹⁶

Topical formulations and skin permeation

Chemistry study A preformulation study for dermal delivery found a strongly negative octanol-buffer distribution coefficient across the pH range tested, which marks the complex as highly hydrophilic.²⁰ Under stress testing the peptide was cleaved in basic and oxidative conditions, and less so in acid, with histidine among the breakdown products.²⁰

Cell study Two laboratory studies on human skin reached different conclusions under different conditions.¹⁹²² Hostynek and colleagues kept a large reservoir of the complex on the skin and measured copper, not the intact peptide; copper crossed dermatomed skin over 48 hours and was also retained in the tissue.¹⁹ Li and colleagues measured both and reported that almost no peptide or copper crossed intact human skin in nine hours, while skin first pierced with a polymer microneedle array let both through.²²

Review A 2026 review found that delivery studies usually report particle size, encapsulation efficiency and bulk release, but seldom resolve whether what is released is intact GHK-Cu, copper-free GHK or free copper.²³

Human evidence

Human study Human evidence for GHK-Cu is thin. The three controlled trials cited here all tested preparations applied to skin or wounds; none tested any other use.¹¹¹²¹³

Human study A multicentre, randomized, evaluator-blinded study compared a GHK-copper gel with vehicle (the gel without the complex) in people with diabetic neuropathic ulcers, all of whom received standardized wound care.¹¹ Median percentage closure of plantar ulcers, those on the sole of the foot, was higher with the gel than with vehicle, and infections were less frequent in plantar ulcers that received the gel straight after the initial debridement (removal of dead tissue).¹¹ The abstract does not give the number of patients.¹¹

Human study A randomized, evaluator-blinded trial in venous stasis ulcers, with 86 evaluable patients, found no difference between a tripeptide-copper cream and placebo.¹² Silver sulfadiazine cream reduced ulcer size more than either.¹²

Human study In a randomized study that 13 patients completed after carbon dioxide laser resurfacing around the mouth, blinded evaluators and computer analysis found no significant difference in redness, wrinkles or overall skin quality between skin-care regimens with and without GHK-Cu.¹³ Patients’ own questionnaire ratings of the change in skin quality were higher in the GHK-Cu group.¹³

Review The 2026 review judged the clinical evidence sparse and below current standards for defining the active substance, and described the historical cosmetic reports as small or incompletely characterized.²³

Regulatory status

PubChem lists prezatide as a synonym for the peptide.¹⁷ On 8 October 2026 Health Canada’s Drug Product Database returned no product with prezatide, or with any ingredient name containing “tripeptide” or “GHK”, as an active ingredient.¹⁴ On the same date the FDA’s Drugs@FDA data returned no approved application with prezatide as an active ingredient.¹⁵ Cosmetic and natural health product rules were not checked for this page.

The FDA’s page on bulk drug substances that may present significant safety risks in compounding, current as of 22 April 2026, lists GHK-Cu for injectable use among substances previously in category 2 of its interim compounding policies whose nominations were withdrawn.²⁴ The entry says that compounded injectable drugs containing GHK-Cu may pose a risk of immunogenicity because of possible aggregation and peptide-related impurities, and that human data on safety are limited.²⁴

ClinicalTrials.gov lists a phase 2, randomized, double-blind, vehicle-controlled study of a GHK-Cu gel on standardized acute skin wounds in healthy adults, sponsored by Hudson Biotech.²⁵ It was shown as recruiting, with no results posted, on 8 October 2026.²⁵

Products on this site are sold for laboratory research use only, as set out in the research use only policy.

In the laboratory

Horizon supplies GHK-Cu as a lyophilized (freeze-dried) powder in sealed vials. The compound also appears in two cream formulations and in the Glow blend with BPC-157 and TB-500. None of the studies cited on this page tested those formulations or that combination.

Three findings bear on bench work:

• Chemistry study The peptide was stable for at least two weeks at elevated temperature in water and mildly acidic to neutral buffers, and broke down under basic and oxidative stress.²⁰
• Chemistry study Other ligands share the copper: glycine and histidine form ternary complexes with GHK-Cu, and albumin competes for the metal.¹²
• Review The 2026 review describes the coordination state and speciation of GHK-Cu as dependent on formulation.²³

Breakdown routes are covered in the guide to peptide stability and degradation, and general conditions for keeping lyophilized material in the peptide storage guide. Batch documents, when they exist, are published on the Lab Results page.