GHK-Cu is a copper-associated form of the tripeptide glycyl-L-histidyl-L-lysine. Its ability to influence extracellular matrix production led to research in wounds and topical skin formulations. Human reports include a positive diabetic-ulcer study, a negative venous-ulcer comparison and small cosmetic studies with mixed outcomes. The preparation, skin condition and measurement explain much of the variation in this literature.
Overview
Molecular profile
- Identity
- Copper-associated glycyl-L-histidyl-L-lysine Source
- Peptide chain
- Gly-L-His-L-Lys (3 residues) Source
- Specified database form
- Prezatide copper, CID 71587328; stereochemically defined one-peptide/one-copper representation Source
- Formula of specified representation
- C14H23CuN6O4+; excludes unspecified counterions and hydration Source
- Molecular weight of specified representation
- 402.92 g/mol Source
Forms and derivatives
Free GHK
The peptide chain without copper in its molecular formula. It can acquire metal associations after contact with a biological solution.
GHK-Cu solution species and stoichiometries
Copper-peptide species depend on conditions and competing ligands. A keratinocyte paper used supplier material described with a 2:1 peptide-to-copper ratio; the molecular table identifies a 1:1 database representation.
Cuprate-diacetate preparation
The copper-tripeptide form used in the human excised-skin diffusion experiment. The assay quantified copper, leaving intact-complex transport unresolved.
GHK-Cu with hyaluronic acid
A screened combination with low-molecular-weight hyaluronic acid increased collagen-IV readouts in cells and ex-vivo skin; formula ratio and assay type matter.
Wound gels, creams and nanocarrier serums
Complete formulations used in the human trials. The nanocarrier control omitted both peptide and carrier, limiting ingredient-specific attribution.
GHK supplies the three-amino-acid chain, while Cu denotes copper. The peptide can coordinate copper(II) through several chemical groups, and the surrounding solution affects which species are present. PubChem's stereochemically defined prezatide-copper record represents a one-peptide, one-copper species with formula C14H23CuN6O4+ and molecular weight 402.92 g/mol. This is a labelled chemical representation; it does not specify every salt, hydration state or solution species in products called GHK-Cu. PubChem CID 71587328, Lau and Sarkar
The research spans copper-tripeptide creams, wound gels, nanocarrier serums, copper complexes with acetate, and reagents added to cells. A skin-toxicity experiment, for example, described supplier material with a two-peptide-to-one-copper ratio. These details help distinguish a defined chemical entity from a formulation or solution containing it. Li et al.
Uses and research areas
The central research area is tissue remodeling: how cells produce, organize and break down the structure around them. Fibroblast and rat-wound experiments measured collagen and other matrix components. Clinical wound studies measured ulcer-size reduction or closure, while cosmetic studies measured redness, wrinkles, participant perception or eyebrow hair growth.
Other experiments extend the questions to stress resistance and aging biology. A 2026 nematode study examined lifespan and mitochondrial function. Its organism-level results are useful for biological hypothesis development, but they address a different scale of evidence from a clinical skin trial. Wen et al.
Mechanism of action
Copper coordination and matrix production
Copper coordination changes the peptide's chemical environment and can influence how the metal is presented to cells. Lau and Sarkar found multiple GHK-copper species under different solution conditions and competition with albumin for copper. This provides a foundation for studying copper handling, without implying that every formulation produces one fixed species. Lau and Sarkar
Maquart and colleagues' 1988 fibroblast experiment found increased collagen synthesis with GHK-Cu independently of changes in cell number. A later rat wound-chamber study found accumulation of collagen, proteins and glycosaminoglycans, the water-binding molecules that contribute to the tissue matrix. These findings connect copper-peptide exposure with matrix production in their respective models. Useful healing additionally depends on the organization, location and mechanical properties of that matrix. Maquart et al., 1988, Maquart et al., 1993
Formulation can change the observed response
Jiang and colleagues tested combinations of GHK-Cu and hyaluronic acid in human dermal fibroblasts and skin samples maintained outside the body. The selected low-molecular-weight hyaluronic-acid combination produced a 25.4-fold collagen-IV expression result in the cell test and a 2.03-fold result in the skin experiment. The cell study used gene-expression measurement, while the tissue study quantified immunofluorescence. Collagen IV forms part of basement membranes, the supportive interface beneath epithelial cells. The different readouts and experimental systems explain why these fold changes cannot be treated as the same measurement of skin improvement. Jiang et al.
The combination illustrates why a serum's formulation base and other ingredients matter. A favorable response to one tested mixture supports research on that formulation; identifying an ingredient's independent contribution requires a comparison that isolates it.
Pharmacokinetics
The sources acquired here do not establish a human plasma half-life for a defined intact GHK-Cu preparation, so no elimination curve is shown. Topical delivery research provides a more concrete observation: copper can penetrate and remain in excised skin after application of a copper-tripeptide preparation.
Hostynek, Dreher and Maibach used diffusion cells with isolated human skin layers and collected receptor fluid over 48 hours. They applied glycyl-L-histidyl-L-lysine cuprate diacetate and measured copper using inductively coupled plasma mass spectrometry. The experiment found both passage through dermatomed skin and retained copper. Because the assay measured the element, it does not establish that intact GHK-Cu crossed the tissue, nor does an excised-skin system determine systemic exposure in a living person. Hostynek, Dreher and Maibach, final publication
Preformulation research also found that GHK-Cu was highly water-preferring and examined its stability with potential formulation components. These properties motivated delivery approaches such as the lipid nanocarrier used in the wrinkle study below. Formulation stability and skin penetration are important steps, but neither supplies a clinical duration of action. Badenhorst, Svirskis and Wu
Research findings
Matrix accumulation in cells and rat wounds
The original collagen experiment demonstrated an effect on fibroblast collagen synthesis without a corresponding increase in cell number. In 1993, Maquart and colleagues implanted mesh wound chambers under rats' skin and introduced GHK-Cu into the chambers. Compared with saline, the treated chambers accumulated more matrix material and showed increased type I and III collagen messenger RNA. A control tripeptide did not produce the same effect. Maquart et al., 1988, Maquart et al., 1993
The chamber model made connective-tissue accumulation measurable. It does not by itself reveal whether a human ulcer would close or whether a repaired tendon would withstand greater load. A later irradiated-rat skin-flap experiment also helps define the limits: topical GHK-Cu gel did not improve flap ischemia, vessel measurements or vascular-growth-factor staining under the investigators' prespecified multiple-comparison threshold. Parker et al.
Contrasting clinical ulcer results
Bishop and colleagues randomized people with venous-stasis ulcers to a copper-tripeptide cream, the carrying cream without the active ingredient, or silver sulfadiazine. Evaluators who measured ulcer size were blinded to treatment, and 86 evaluable patients completed the study. The copper-tripeptide cream did not shrink ulcers more than its vehicle, while silver sulfadiazine reduced ulcer size more than either cream. The copper preparation was described as a 0.4% cream; the accessed record did not establish which copper-peptide species were present in solution. Bishop et al.
Mulder and colleagues studied a GHK-copper wound gel in diabetic neuropathic ulcers within a standardized care program that included debridement, pressure relief and diabetes education. Their randomized report compared the active gel with its carrying gel without the active copper peptide; the evaluators were blinded to treatment. The median reduction in plantar-ulcer area was greater with the active gel: 98.5% versus 60.8%, with P<0.05. This measures how much ulcer area shrank. The accessible abstract does not supply the denominator, assessment time or confidence interval needed to judge the estimate fully. Mulder et al.
The positive and negative findings concern different wound diseases and formulations. They establish the value of testing copper-peptide preparations in a specified care setting, while leaving general efficacy across chronic wounds unresolved.
Skin after laser resurfacing
Miller and colleagues randomized patients undergoing circumoral carbon-dioxide laser resurfacing to skin-care regimens with or without GHK-Cu. Thirteen completed the study. Computer analysis and blinded evaluators found no significant difference in redness resolution, wrinkles or overall skin quality. A patient questionnaire favored the GHK-Cu regimen for perceived skin quality, with P=0.04. Miller et al.
Perceived improvement and measured appearance can differ because they capture different aspects of experience. Both are relevant observations, and neither should replace the other when describing this small post-procedure comparison.
Wrinkle measurements with a nanocarrier serum
Badenhorst and colleagues enrolled 40 women aged 40–65 in an eight-week split-face study; 39 completed it. The GHK-Cu lipid-nanocarrier serum was applied to a fixed facial side, with either the serum base without GHK-Cu and its nanocarrier (the vehicle), or a commercial serum, used on the opposite side. In the vehicle-comparison group, mean wrinkle-volume changes from baseline were −24.1% with the test serum and −15.0% with vehicle. Modeled volume and depth comparisons favored the test formulation over vehicle. The depth comparison with the commercial serum gave P=0.0577. Badenhorst et al., Methods and Tables 2–3
The study provides a measured cosmetic signal with two consequential design limits: treatment side was fixed, and vehicle omitted both GHK-Cu and its nanocarrier. The comparison therefore cannot separate peptide and carrier contributions. A percentage describing the difference between treatments also uses a different denominator from each side's change from baseline.
Preliminary eyebrow and organism studies
A 2026 proceedings-format report by Bo and colleagues described a randomized, double-blind split-face comparison in 18 adults. A serum labelled 2% GHK-Cu produced favorable eyebrow-hair-count and diameter results over 12 weeks. The accessible abstract supplies no between-side effect size or confidence interval, and the complete methods were not acquired. This makes it a preliminary formulation-specific cosmetic finding; scalp-hair-loss treatment requires its own population and endpoints. Bo et al.
Wen and colleagues reported longer lifespan and better stress resistance in Caenorhabditis elegans exposed to GHK-Cu. Their experiments linked the response with mitochondrial measurements and DAF-16 and SKN-1, regulators involved in stress-response gene activity in the worm. These findings broaden the mechanistic questions beyond skin. Human longevity and cognition were not studied. Wen et al.
Safety and tolerability
The topical reports provide limited safety information for their formulas. In the nanocarrier study, one participant withdrew after reactions on both facial sides, and symptoms resolved after stopping application. The small eyebrow report stated that no serious adverse effects or allergic reactions occurred. Sparse event reporting and small samples leave uncommon effects unresolved. Badenhorst et al., Bo et al.
A human-keratinocyte study compared a supplier-described GHK-Cu preparation with copper chloride and copper acetate. The tested peptide complex caused fewer irritation-related responses under those culture conditions. This is useful chemistry-dependent safety evidence, while clinical irritation and allergy remain questions about the complete applied product. Li et al.
FDA specifically identifies compounded injectable GHK-Cu as a substance with potential immunogenicity concerns from aggregation and peptide impurities, together with limited human safety data. That route-specific assessment should be kept alongside the topical findings because systemic exposure creates different safety questions. An ingredient's presence in cosmetics does not confer FDA approval as a treatment for wounds, hair loss or aging; no approved therapeutic indication was identified in this review. FDA compounding-safety record
What the research means
GHK-Cu has credible experimental activity in matrix biology and several human topical comparisons worth examining. The clinical evidence is mixed and often specific to one preparation. A positive diabetic-ulcer result, a negative venous-ulcer result and a measured wrinkle response therefore belong in the same account, with their different comparators and outcomes intact.
The next clinically useful evidence would identify the copper-peptide species and complete formula, isolate the contribution of the active ingredient, and measure an outcome that matters for the condition being treated. Larger and longer studies would also clarify durability and harms. For claims about systemic repair or longevity, the existing topical and worm studies leave a much larger gap between experimental activity and demonstrated human benefit.
FAQs
Does GHK-Cu have one universal molecular formula?
A formula requires a specified chemical representation. The table gives PubChem's stereochemically defined 1:1 prezatide-copper record. Counterions, hydration, stoichiometry and solution equilibria can differ among studied preparations, so that formula cannot describe every product sold under the name.
Does 98.5% ulcer area closure mean that 98.5% of patients healed?
The diabetic-ulcer report gives a median percentage change in plantar-ulcer area. The proportion of patients completely healed is a separate endpoint with its own denominator. The acquired abstract does not supply the full sample and time-point information needed to interpret the estimate completely.
Why did the clinical wound studies disagree?
The venous-ulcer trial and diabetic-ulcer trial studied different diseases, formulations and care settings. The venous-ulcer trial did not establish greater ulcer-size reduction with the copper cream than with the carrying cream without peptide. In the diabetic-ulcer study, ulcer area shrank more with the active gel than with the comparison gel. These separate results do not establish that one formulation works across all chronic wounds.
What can be learned from skin copper penetration?
It shows that measured copper can pass through or remain in excised skin after application of the tested copper-tripeptide preparation. The elemental assay cannot determine whether intact GHK-Cu crossed the tissue, and the experiment does not measure systemic exposure in a living person.
Can the serum or worm studies validate injections or human longevity?
The serum studies address topical cosmetic formulations; the nematode study addresses lifespan and stress responses in a laboratory organism. Injectable clinical benefit, systemic safety and human longevity require their own direct studies. FDA specifically identifies safety uncertainties for compounded injectable GHK-Cu.
Comparisons and related reading
References
GHK-Cu increased collagen synthesis in cultured fibroblasts independently of cell-number change.
Rat wound chambers accumulated more matrix material with GHK-Cu, with increased collagen-I and -III messenger RNA.
The 13-completer post-laser study found no objective advantage but a favorable patient-rated skin-quality comparison.
A selected GHK-Cu/hyaluronic-acid combination increased collagen-IV readouts differently in fibroblast gene-expression and ex-vivo skin-immunofluorescence tests.
A small proceedings-format eyebrow-serum report described favorable hair-count and diameter observations; the accessible abstract omitted between-side estimates.
GHK-Cu extended nematode lifespan and changed stress-resistance and mitochondrial measures, with worm pathway associations.
The venous-ulcer trial did not establish greater ulcer-size reduction with the copper-tripeptide cream than with the carrying cream without peptide; silver sulfadiazine reduced ulcer size more than either cream.
In the eight-week split-face study in women, wrinkle volume and depth decreased more with the GHK-Cu nanocarrier serum than with the comparison serum base. That base lacked both GHK-Cu and its nanocarrier, and treatment was always on the same facial side.
The standardized-care diabetic-ulcer comparison reported greater median plantar-ulcer area closure with GHK-copper gel; the acquired abstract lacked denominator and time point.
Solution experiments demonstrated multiple GHK-copper species and albumin competition.
Defines the stereochemically specified one-peptide/one-copper representation, its positive charge, formula and molecular weight.
The final skin-diffusion publication measured copper after applying a cuprate-diacetate preparation, providing a transport observation for copper in excised tissue.
Identifies the 2011 paper as a duplicate preliminary version and directs readers to the revised final 2010 publication.
Despite the abbreviated peptide wording in the title, the abstract identifies GHK-Cu as the tested preparation and describes GHK quantification during formulation studies.
Agency safety context distinguishes injectable GHK-Cu and the thymosin β4 fragment from other preparations.
An irradiated-rat flap experiment found no improvement in ischemia, vessel measures or VEGF staining under its prespecified significance threshold.
Keratinocyte assays compared a supplier-described 2:1 copper-peptide preparation with copper salts and found fewer irritation-associated responses under the tested culture conditions.
Glossary
- Extracellular matrix
- The proteins and other molecules surrounding cells that support tissue structure and organization.
- Glycosaminoglycan
- A long sugar-containing molecule that contributes to water retention and tissue-matrix properties.
- Collagen IV
- A collagen that forms a network in basement membranes beneath epithelial cells.
- Vehicle
- The formulation base used to deliver an ingredient or serve as its comparator.
- Split-face study
- A study comparing treatments applied to opposite sides of a participant's face.
- Immunogenicity
- The capacity of a substance to provoke an immune response.
- ICP-MS
- Inductively coupled plasma mass spectrometry, an analytical method used here to quantify copper.