GHK-Cu Research Library: Every Study, Plain English

The GHK-Cu Research Library is a maintained index of the published science on GHK-Cu (Copper Tripeptide-1): 60 studies from 1977 to 2026, organized by outcome, each with a plain-English summary of what it actually showed and a direct link to the original paper on PubMed. Dr. Loren Pickart, who discovered GHK-Cu in 1973 and authored much of this literature, passed away in 2023; this library exists so the research record stays organized, readable, and honestly labeled.

Read the badges. Most GHK-Cu evidence is preclinical: cell studies, animal models, ex vivo skin. Human trials exist but are small. Every entry below is labeled by study type, because a cosmetic ingredient's literature deserves the same honesty as its label. This page reports what studies found; it does not claim products will reproduce those findings.
60
indexed studies
7
human studies
49
years of research (1977-2026)
100%
PubMed-linked, no dead citations

Skin Remodeling & Collagen 13 studies

Studies on GHK-Cu and collagen synthesis, skin density, firmness, and visible aging.

Ex vivo human skin 2026

Multi-Target Restoration of Dermal Elastic Fibers Through Elastin Upregulation, Elastase Suppression, and Scaffold Reinforcement.

Ye S et al - Current issues in molecular biology

Copper Tripeptide-1 increased elastin expression and secretion in dermal fibroblasts, and a three-ingredient combination containing it improved elastic fibre architecture in UV-damaged human skin biopsy samples.

PMID 42193036 | DOI 10.3390/cimb48050431

In vitro 2026

Redox-Responsive GHK-Conjugated Sponge Spicules for Sustained Dermal Delivery and Enhanced Collagen Synthesis.

Hong WK et al - Micromachines

A redox-responsive sponge-spicule carrier delivered more GHK into a bioprinted artificial human skin model than a simple spicule-peptide mixture and increased type I collagen expression in human dermal fibroblasts.

Reported figure: delivered 9.72 ng/cm2 of GHK versus 1.9 ng/cm2 for the physical mixture; ~60% cumulative release over 35 days with 10 mM glutathione

PMID 42354780 | DOI 10.3390/mi17060750

Human (open label) 2025

Efficacy and Safety Assessment of ThriveCo Scar Fader Gel With Scarcede™ in the Treatment of Skin Scars.

Patel MN et al - Cureus

In an open-label study in women with acne scars, a gel containing copper tripeptide-1 plus three other actives was followed by improved scar scores and skin smoothness at days 21 and 45, with no adverse effects reported; the abstract does not state how many participants took part.

Reported figure: scar appearance reduced 7.17% at day 21 (p<0.001) and 26.57% at day 45 (p<0.0001); smoothness improved 33.08% and 44.56%

PMID 41001334 | DOI 10.7759/cureus.90934

Ex vivo human skin 2023

Synergy of GHK-Cu and hyaluronic acid on collagen IV upregulation via fibroblast and ex-vivo skin tests.

Jiang F et al - Journal of cosmetic dermatology

GHK-Cu combined with low-molecular-weight hyaluronic acid at a 1:9 ratio raised collagen IV in human dermal fibroblasts and in an ex-vivo human skin model.

Reported figure: collagen IV up 25.4 times in cell test and 2.03 times in ex-vivo skin test

PMID 37062921 | DOI 10.1111/jocd.15763

In vitro 2020

Effect of oligoarginine conjugation on the antiwrinkle activity and transdermal delivery of GHK peptide.

Hur GH et al - Journal of peptide science : an official publication of the European Peptide Society

Conjugating four arginines to GHK improved its cell penetration and produced greater anti-wrinkle activity and collagen biosynthesis at lower doses than unconjugated GHK in laboratory tests.

PMID 31788907 | DOI 10.1002/psc.3234

Human (open label) 2016 n=1

Significant improvement in crow's feet after treatment with Jet-M and a mixed solution of copper-GHK, oligo-hyaluronic acid, rhodiolar extract, tranexamic acid, and β-glucan (GHR formulation).

Byun SY et al - Journal of cosmetic and laser therapy : official publication of the European Society for Laser Dermatology

In a single 59-year-old man treated weekly for 12 weeks, a Jet-M device plus a multi-ingredient solution containing copper-GHK was followed by visibly reduced crow's feet and increased collagen, fibrillin-1 and procollagen type 1 on biopsy, with no adverse effects.

PMID 27064823 | DOI 10.3109/14764172.2016.1157367

In vitro 2014

Effect of GLY-HIS-LYS and its copper complex on TGF-β secretion in normal human dermal fibroblasts.

Gruchlik A et al - Acta poloniae pharmaceutica

In cultured normal human dermal fibroblasts, GHK, GHK-Cu and free copper ions each reduced IGF-2-driven TGF-beta1 secretion.

Reported figure: 1 nM peptide solutions; IGF-2 at 100 ng/mL

PMID 25745767

In vitro 2012

Stem cell recovering effect of copper-free GHK in skin.

Choi HR et al - Journal of peptide science : an official publication of the European Peptide Society

In cultured human keratinocytes and skin-equivalent models, copper-free GHK also increased keratinocyte proliferation, integrin expression and p63/PCNA-positive cell numbers.

PMID 23019153 | DOI 10.1002/psc.2455

In vitro 2009

Copper-GHK increases integrin expression and p63 positivity by keratinocytes.

Kang YA et al - Archives of dermatological research

In cultured human keratinocytes and skin-equivalent models, copper-GHK increased keratinocyte proliferation and raised integrin alpha6/beta1, p63 and PCNA levels.

PMID 19319546 | DOI 10.1007/s00403-009-0942-x

Human RCT 2006 n=13

Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin.

Miller TR et al - Archives of facial plastic surgery

In 13 patients randomised after CO2 laser resurfacing, adding GHK-Cu skin care produced no measurable difference in erythema resolution or wrinkle improvement, and only the patient-reported overall skin quality score favoured GHK-Cu.

Reported figure: P = .04 for patient-reported overall skin quality; no significant difference on blinded/computer erythema and wrinkle measures

PMID 16847171 | DOI 10.1001/archfaci.8.4.252

In vitro 2001

The effect of copper tripeptide and tretinoin on growth factor production in a serum-free fibroblast model.

McCormack MC et al - Archives of facial plastic surgery

In serum-free cultures of human facial skin fibroblasts, copper tripeptide lowered TGF-beta1 secretion by keloid-producing cells at 24 hours, which the authors suggest could relate to reducing excess scar formation.

Reported figure: copper tripeptide 1 x 10(-9) mol/L; P<.05 at 24 hours

PMID 11176716

In vitro 1992

Stimulation of sulfated glycosaminoglycan synthesis by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+.

Wegrowski Y et al - Life sciences

In cultured normal human fibroblasts, GHK-Cu raised glycosaminoglycan synthesis in a dose-dependent, biphasic way, favouring dermatan sulfate and heparan sulfate but not hyaluronic acid.

Reported figure: maximal stimulation at 10(-9) to 10(-8) M

PMID 1522753 | DOI 10.1016/0024-3205(92)90504-i

In vitro 1988

Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+.

Maquart FX et al - FEBS letters

In cultured fibroblasts, GHK-Cu increased collagen synthesis without changing cell number.

Reported figure: stimulation began between 10(-12) and 10(-11) M, maximized at 10(-9) M

PMID 3169264 | DOI 10.1016/0014-5793(88)80509-x

Wound Healing & Repair 12 studies

The original GHK-Cu research territory: tissue repair, remodeling, and recovery models.

Animal 2024 n=80

Effects of Gly-His-Lys-D-Ala Peptide on Skin Wound Regeneration Processes.

Rakhmetova KK et al - Bulletin of experimental biology and medicine

In 80 male Wistar rats with surgically debrided skin wounds, daily intracutaneous Gly-His-Lys-D-Ala increased fibroblastic cells and macrophages, reduced granulocytes and was associated with active wound contraction by day 30.

Reported figure: dose 0.5 microg/kg

PMID 38345677 | DOI 10.1007/s10517-024-06035-w

Animal 2017

GHK-Cu-liposomes accelerate scald wound healing in mice by promoting cell proliferation and angiogenesis.

Wang X et al - Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society

In a mouse scald model, liposome-encapsulated GHK-Cu improved angiogenesis versus free GHK-Cu and the wounds healed by day 14, and in endothelial cell culture it raised proliferation and VEGF and FGF-2 expression.

Reported figure: HUVEC proliferation rate increased 33.1%; wound healing time shortened to 14 days

PMID 28370978 | DOI 10.1111/wrr.12520

Animal 2015 n=72

Tripeptide-copper complex GHK-Cu (II) transiently improved healing outcome in a rat model of ACL reconstruction.

Fu SC et al - Journal of orthopaedic research : official publication of the Orthopaedic Research Society

In 72 rats after anterior cruciate ligament reconstruction, intra-articular GHK-Cu reduced knee laxity difference at 6 weeks but the benefit was gone by 12 weeks, with no difference in ultimate load, gait or histology.

Reported figure: knee laxity p = 0.009 at 6 weeks; graft stiffness p = 0.026 at 6 weeks in the 0.3 mg/ml group; no significant difference at 12 weeks

PMID 25731775 | DOI 10.1002/jor.22831

Animal 2013 n=23

Effects of topical copper tripeptide complex on wound healing in an irradiated rat model.

Parker NP et al - Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery

In irradiated rat dorsal skin flaps, twice-daily topical GHK-Cu gel showed no difference from control in flap ischemia, blood vessel number or area, or VEGF expression.

Reported figure: mean ischemic area 5.0 cm2 (test) vs 3.8 cm2 (control), P = .011 against a prespecified threshold of P < .01

PMID 23744835 | DOI 10.1177/0194599813492644

Animal 2007

A therapeutic approach for diabetic wound healing using biotinylated GHK incorporated collagen matrices.

Arul V et al - Life sciences

In streptozotocin-induced diabetic rats, a collagen matrix carrying biotinylated GHK sped wound contraction and raised skin glutathione and ascorbic acid compared with untreated and plain-collagen controls.

PMID 17049946 | DOI 10.1016/j.lfs.2006.09.018

Animal 2003 n=24

The effect of topical tripeptide-copper complex on healing of ischemic open wounds.

Canapp SO Jr et al - Veterinary surgery : VS

In 24 rats with ischemic open wounds, topical tripeptide-copper complex accelerated wound area reduction versus vehicle and untreated control and lowered wound TNF-alpha, MMP-2 and MMP-9.

Reported figure: by day 13 initial wound area decreased 64.5% (TCC), 45.6% (vehicle), 28.2% (control)

PMID 14648529 | DOI 10.1111/j.1532-950x.2003.00515.x

In vitro 2000

The tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ stimulates matrix metalloproteinase-2 expression by fibroblast cultures.

Siméon A et al - Life sciences

In cultured dermal fibroblasts, GHK-Cu raised MMP-2 protein and mRNA plus TIMP-1 and TIMP-2 secretion; copper ions alone reproduced the effect but GHK alone did not.

PMID 11045606 | DOI 10.1016/s0024-3205(00)00803-1

Animal 2000

Expression of glycosaminoglycans and small proteoglycans in wounds: modulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu(2+).

Siméon A et al - The Journal of investigative dermatology

In rat wound chambers, repeated GHK-Cu injections increased wound tissue mass, type I collagen and glycosaminoglycans, and raised decorin mRNA while lowering biglycan mRNA.

Reported figure: 2 mg per injection

PMID 11121126 | DOI 10.1046/j.1523-1747.2000.00166.x

Animal 1999

Expression and activation of matrix metalloproteinases in wounds: modulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+.

Siméon A et al - The Journal of investigative dermatology

In rat wound chambers, GHK-Cu injections prolonged MMP-9 expression and raised pro-MMP-2 and activated MMP-2 during the later stages of healing, showing it modulates matrix remodelling enzymes rather than only building matrix.

Reported figure: 2 mg GHK-Cu per injection; effects at days 18 and/or 22

PMID 10383745 | DOI 10.1046/j.1523-1747.1999.00606.x

Animal 1995

Effect of tripeptide-copper complexes on the process of skin wound healing and on cultured fibroblasts.

Buffoni F et al - Archives internationales de pharmacodynamie et de therapie

In guinea-pig dorsal skin wounds, Gly-His-Lys-Cu and synthetic analogues produced slower skin reorganisation and delayed fibroblast activation, and in cultured fibroblasts they decreased cell reproduction while increasing collagen expression.

Reported figure: peptides tested at 10(-7) M in fibroblast culture

PMID 8836453

Animal 1993

In vivo stimulation of connective tissue accumulation by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+ in rat experimental wounds.

Maquart FX et al - The Journal of clinical investigation

In rat subcutaneous wound chambers, injected GHK-Cu produced a concentration-dependent increase in dry weight, DNA, total protein, collagen and glycosaminoglycan content, while an inactive control tripeptide did not.

Reported figure: stimulation of collagen synthesis was twice that of noncollagen proteins

PMID 8227353 | DOI 10.1172/JCI116842

Human RCT 1992 n=86

A prospective randomized evaluator-blinded trial of two potential wound healing agents for the treatment of venous stasis ulcers.

Bishop JB et al - Journal of vascular surgery

In 86 evaluable patients with venous stasis ulcers, a 0.4% tripeptide copper complex cream performed no better than inert placebo, while silver sulfadiazine 1% cream significantly reduced ulcer size.

Reported figure: no difference between tripeptide copper complex 0.4% cream and placebo

PMID 1495150 | DOI 10.1067/mva.1992.37086

Hair & Follicles 5 studies

GHK-Cu and follicle biology. Note how much of this evidence is preclinical.

Human (open label) 2024

An Assessment of the Safety, Efficacy, and Tolerability of a Novel Scalp Treatment Regimen Combining a Hydroxy Acid-Based Scrub and Copper Tripeptide Serum in the Management of Seborrheic Dermatitis in Adults.

Patel MN et al - Cureus

In an uncontrolled 15-day open-label study of adults with mild to moderate dandruff, a two-step regimen of a hydroxy acid scrub plus a serum containing copper tripeptide-1 and four other actives improved scalp flaking, hydration, hair density and thickness; the abstract does not state how many participants took part.

Reported figure: adherent scalp flaking score improved 61.24% (p<0.0001); hair density +12.48% and hair thickness +25.36% (both p<0.0001); scalp hydration +76.24% (p<0.0001)

PMID 39449909 | DOI 10.7759/cureus.70108

Animal 2020

QR678 & QR678 Neo Hair Growth Formulations: A Cellular Toxicity & Animal Efficacy Study.

Kapoor R et al - Plastic and reconstructive surgery. Global open

In mice given intradermal injections of hair formulations containing copper tripeptide-1 among other growth factors, hair growth appeared at injection sites, and the individual components were not cytotoxic to cultured human keratinocytes and fibroblasts.

Reported figure: hair retention within a 0.25-cm radius around the injection site

PMID 32983753 | DOI 10.1097/GOX.0000000000002843

Human (open label) 2018 n=1000

Intradermal injections of a hair growth factor formulation for enhancement of human hair regrowth - safety and efficacy evaluation in a first-in-man pilot clinical study.

Kapoor R et al - Journal of cosmetic and laser therapy : official publication of the European Society for Laser Dermatology

In an uncontrolled open-label study of 1000 patients receiving eight intradermal scalp injections of a formulation containing copper tripeptide-1 plus five growth factors, 83% showed reduced hair fall on pull testing and total hair count was higher at 1 year.

Reported figure: 83% of patients had significant reduction in hair fall on pull test; total hair count increase at 1 year P = 0.002

PMID 29482481 | DOI 10.1080/14764172.2018.1439965

Human RCT 2016 n=45

Efficacy of a Complex of 5-Aminolevulinic Acid and Glycyl-Histidyl-Lysine Peptide on Hair Growth.

Lee WJ et al - Annals of dermatology

In 45 men with pattern hair loss treated once daily for 6 months, a complex of 5-aminolevulinic acid and GHK peptide increased hair count more than placebo, with no adverse events and no difference in hair length or thickness.

Reported figure: hair count increase over 6 months 52.6 (group A, p<0.05), 71.5 (group B, p<0.05), 9.6 (placebo)

PMID 27489425 | DOI 10.5021/ad.2016.28.4.438

Animal 1991

The hair follicle-stimulating properties of peptide copper complexes. Results in C3H mice.

Trachy RE et al - Annals of the New York Academy of Sciences

PubMed holds no abstract for this paper; the title reports hair follicle-stimulating properties of peptide copper complexes in C3H mice.

PMID 1809108 | DOI 10.1111/j.1749-6632.1991.tb24420.x

Antioxidant & Calming Actions 10 studies

Oxidative stress, inflammation markers, and protective effects.

Animal 2026

Glycyl-L-histidyl-L-lysine-Cu2(+) (GHK-Cu) Attenuates CuSO(4) or LPS induced-inflammation in Zebrafish larvae model.

Hu J et al - European journal of pharmacology

In zebrafish larvae with copper sulfate- or lipopolysaccharide-induced inflammation, GHK-Cu reduced neutrophil and macrophage migration and pro-inflammatory cytokine expression, lowered nitric oxide and reactive oxygen species and raised superoxide dismutase activity.

PMID 41997403 | DOI 10.1016/j.ejphar.2026.178880

In vitro 2026

A Torilis japonica Extract-GHK-Cu Complex Attenuates Th2 Cytokines and Promotes Keratinocyte Recovery: A Potential Antioxidant Strategy for Atopic Dermatitis.

Jeon S et al - Antioxidants (Basel, Switzerland)

In a TNF-alpha/IFN-gamma-stimulated HaCaT keratinocyte model of atopic dermatitis, a Torilis japonica extract plus GHK-Cu complex suppressed Th2 cytokine transcription, promoted keratinocyte migration and scavenged radicals without reducing cell viability.

Reported figure: optimal 6:4 ratio of Torilis japonica extract to GHK-Cu

PMID 42510549 | DOI 10.3390/antiox15070818

Animal 2024

The glycyl-l-histidyl-l-lysine-Cu(2+) tripeptide complex attenuates lung inflammation and fibrosis in silicosis by targeting peroxiredoxin 6.

Bian Y et al - Redox biology

In a mouse silicosis model and cultured macrophages, GHK-Cu bound peroxiredoxin 6 and reduced lung inflammation and fibrosis without significant systemic toxicity.

PMID 38879894 | DOI 10.1016/j.redox.2024.103237

Animal 2023

Glycyl-l-histidyl-l-lysine-Cu(2+) rescues cigarette smoking-induced skeletal muscle dysfunction via a sirtuin 1-dependent pathway.

Deng M et al - Journal of cachexia, sarcopenia and muscle

Plasma GHK was measured as lower in 9 patients with COPD than in 11 age-matched healthy people, and in mice exposed to cigarette smoke GHK-Cu reduced muscle mass loss and weakness through SIRT1.

Reported figure: plasma GHK 70.27 +/- 38.87 ng/mL in COPD vs 133.0 +/- 54.54 ng/mL in controls, P = 0.009

PMID 36905132 | DOI 10.1002/jcsm.13213

Animal 2020

Protective effects of GHK-Cu in bleomycin-induced pulmonary fibrosis via anti-oxidative stress and anti-inflammation pathways.

Ma WH et al - Life sciences

In mice with bleomycin-induced pulmonary fibrosis, intraperitoneal GHK-Cu reduced inflammatory cytokines and collagen deposition and corrected the MMP-9/TIMP-1 imbalance via Nrf2, NF-kappaB and TGF-beta1/Smad signalling.

Reported figure: GHK-Cu at 0.2, 2 and 20 microg/g/day on alternate days

PMID 31809714 | DOI 10.1016/j.lfs.2019.117139

In vitro 2018

The peptide glycyl-ʟ-histidyl-ʟ-lysine is an endogenous antioxidant in living organisms, possibly by diminishing hydroxyl and peroxyl radicals.

Sakuma S et al - International journal of physiology, pathophysiology and pharmacology

In Caco-2 cells and in chemical spin-trapping systems, GHK reduced reactive oxygen species and quenched hydroxyl and peroxyl radicals but not superoxide, with a stronger effect on hydroxyl radicals than carnosine or glutathione.

Reported figure: effect seen at GHK concentrations of 10 microM or less

PMID 30042814

Animal 2017

GHK Peptide Inhibits Bleomycin-Induced Pulmonary Fibrosis in Mice by Suppressing TGFβ1/Smad-Mediated Epithelial-to-Mesenchymal Transition.

Zhou XM et al - Frontiers in pharmacology

In mice with bleomycin-induced pulmonary fibrosis, intraperitoneal GHK at three doses reduced inflammatory infiltration, collagen deposition and fibrosis markers via the TGF-beta1/Smad and IGF-1 pathways.

Reported figure: GHK 2.6, 26 and 260 microg/ml/day every other day from day 4 to day 21

PMID 29311918 | DOI 10.3389/fphar.2017.00904

Animal 2016

The tri-peptide GHK-Cu complex ameliorates lipopolysaccharide-induced acute lung injury in mice.

Park JR et al - Oncotarget

In mice with lipopolysaccharide-induced acute lung injury and in cultured macrophages, GHK-Cu lowered reactive oxygen species, TNF-alpha and IL-6, raised superoxide dismutase activity and reduced lung inflammatory cell infiltration.

PMID 27517151 | DOI 10.18632/oncotarget.11168

In vitro 2012

Effect of Gly-Gly-His, Gly-His-Lys and their copper complexes on TNF-alpha-dependent IL-6 secretion in normal human dermal fibroblasts.

Gruchlik A et al - Acta poloniae pharmaceutica

In cultured normal human dermal fibroblasts, GHK, Gly-Gly-His, copper chloride and their copper complexes all reduced TNF-alpha-driven IL-6 secretion.

PMID 23285694

In vitro 2007

Glycyl-histidyl-lysine (GHK) is a quencher of alpha,beta-4-hydroxy-trans-2-nonenal: a comparison with carnosine. insights into the mechanism of reaction by electrospray ionization mass spectrometry, 1H NMR, and computational techniques.

Beretta G et al - Chemical research in toxicology

In buffer at physiological pH, GHK quenched the reactive lipid-peroxidation aldehyde 4-hydroxy-2-nonenal, though significantly less potently than carnosine.

Reported figure: GHK 1 mM against HNE 50 microM

PMID 17672515 | DOI 10.1021/tx700185s

Gene Expression 6 studies

The modern era: GHK-Cu resetting gene expression patterns, from the 2018 gene-data review onward.

Animal 2026

The GHK-Cu delays aging in Caenorhabditis elegans via coordinated regulation of mitochondrial function and activation of DAF-16/SKN-1 pathways.

Wen H et al - Biogerontology

In the nematode Caenorhabditis elegans, GHK-Cu extended lifespan and improved stress resistance, motility and mitochondrial measures, acting through the DAF-16 and SKN-1 pathways.

PMID 42084774 | DOI 10.1007/s10522-026-10444-x

In vitro 2024

Glycyl-l-histidyl-l-lysine prevents copper- and zinc-induced protein aggregation and central nervous system cell death in vitro.

Min JH et al - Metallomics : integrated biometal science

In cell-free and cultured central nervous system cell experiments, GHK bound copper, reduced its redox activity, prevented copper- and zinc-induced protein aggregation and cell death, and re-solubilised aggregated protein.

PMID 38599632 | DOI 10.1093/mtomcs/mfae019

Review 2017

The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline.

Pickart L et al - Brain sciences

A review of Broad Institute Connectivity Map analyses reporting that GHK modulates the expression of many genes relevant to nervous system function and cognitive decline.

PMID 28212278 | DOI 10.3390/brainsci7020020

Review 2014

GHK and DNA: resetting the human genome to health.

Pickart L et al - BioMed research international

A review by GHK's discoverer arguing that GHK shifts gene expression in diseased cells from cancer and COPD patients toward a healthier pattern, and discussing the pathways involved.

PMID 25302294 | DOI 10.1155/2014/151479

In vitro 1980

Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells.

Pickart L et al - Nature

The plasma tripeptide GHK was shown to form complexes with copper(II) and to increase copper uptake into cultured hepatoma cells, supporting its proposed role as a copper transport factor.

PMID 7453802 | DOI 10.1038/288715a0

In vitro 1977

Growth-modulating serum tripeptide is glycyl-histidyl-lysine.

Schlesinger DH et al - Experientia

PubMed holds no abstract for this paper; the title reports that the growth-modulating serum tripeptide was identified as glycyl-histidyl-lysine.

PMID 858356 | DOI 10.1007/BF02002806

Safety & Toxicology 5 studies

Irritation, sensitization, and toxicology data.

In vitro 2023

Liposomes as Carriers of GHK-Cu Tripeptide for Cosmetic Application.

Dymek M et al - Pharmaceutics

Stable liposomes roughly 100 nm across were produced as GHK-Cu carriers, and the encapsulated peptide retained tyrosinase and elastase inhibition in laboratory assays.

Reported figure: encapsulation efficiency 31.7 +/- 0.9% (cationic) and 20.0 +/- 2.8% (anionic) liposomes

PMID 37896245 | DOI 10.3390/pharmaceutics15102485

In vitro 2016

Selected Biomarkers Revealed Potential Skin Toxicity Caused by Certain Copper Compounds.

Li H et al - Scientific reports

In a keratinocyte-based irritation model, GHK-Cu was not cytotoxic and did not significantly change skin irritation biomarkers, whereas copper chloride and copper acetate upregulated IL-1alpha, IL-8, HSPA1A and FOSL1.

Reported figure: CuCl2 and Cu(OAc)2 effects at 58 and 580 microM

PMID 27892491 | DOI 10.1038/srep37664

Ex vivo human skin 2015

Microneedle-Mediated Delivery of Copper Peptide Through Skin.

Li H et al - Pharmaceutical research

Pre-treating human skin with a polymeric microneedle array allowed GHK-Cu and copper to permeate, whereas almost none crossed intact human skin, and no obvious skin irritation was seen.

Reported figure: over 9 h, 134 +/- 12 nanomoles peptide and 705 +/- 84 nanomoles copper permeated microneedle-treated skin versus almost none through intact skin

PMID 25690343 | DOI 10.1007/s11095-015-1652-z

Ex vivo human skin 2011

Human skin penetration of a copper tripeptide in vitro as a function of skin layer.

Hostynek JJ et al - Inflammation research : official journal of the European Histamine Research Society ... [et al.]

A companion analysis in isolated human stratum corneum, epidermis and dermatomed skin quantified how much copper applied as a GHK cuprate crosses and is retained by each skin layer over 48 hours.

Reported figure: permeability coefficient 2.43 +/- 0.51 x 10(-4) cm/h; 136.2 +/- 17.5 microg/cm2 permeated; 97 +/- 6.6 microg/cm2 retained as depot

PMID 20721598 | DOI 10.1007/s00011-010-0238-9

Ex vivo human skin 2010

Human skin retention and penetration of a copper tripeptide in vitro as function of skin layer towards anti-inflammatory therapy.

Hostynek JJ et al - Inflammation research : official journal of the European Histamine Research Society ... [et al.]

In flow-through diffusion cells using isolated human skin, copper applied as a GHK cuprate permeated the skin and was also retained in the tissue as a depot.

Reported figure: permeability coefficient 2.43 +/- 0.51 x 10(-4) cm/h; 136.2 +/- 17.5 microg/cm2 copper permeated over 48 h; 82 +/- 8.1 microg/cm2 retained

PMID 20703511 | DOI 10.1007/s00011-010-0214-4

Reviews & Landmark Papers 9 studies

Review articles and the papers that defined the field.

Review 2025

Are We Ready to Measure Skin Permeation of Modern Antiaging GHK-Cu Tripeptide Encapsulated in Liposomes?

Ogórek K et al - Molecules (Basel, Switzerland)

A methodological review concluding that the transport of liposome-encapsulated GHK-Cu across skin has received little study and that suitable measurement methods are still lacking.

PMID 39795193 | DOI 10.3390/molecules30010136

Review 2025

Topically applied GHK as an anti-wrinkle peptide: Advantages, problems and prospective.

Mortazavi SM et al - BioImpacts : BI

A review of topical GHK as an anti-wrinkle peptide that finds the cellular evidence convincing but reports a surprising absence of clinical studies on GHK-Cu and palmitoyl-GHK, alongside real skin-permeability limits.

PMID 39963574 | DOI 10.34172/bi.30071

Review 2025

Exploring the Role of Tripeptides in Wound Healing and Skin Regeneration: A Comprehensive Review.

Adnan SB et al - International journal of medical sciences

A review of tripeptides in wound healing covering studies published 2016 to 2025, reporting that GHK-based formulations such as nanoparticle conjugates and hydrogels enhance fibroblast migration, matrix remodelling and wound closure.

PMID 41209547 | DOI 10.7150/ijms.118118

Review 2024

The naturally occurring peptide GHK reverses age-related fibrosis by modulating myofibroblast function.

He Q et al - Aging pathobiology and therapeutics

A commentary discussing evidence that GHK modulates myofibroblast function and cellular senescence in age-related fibrosis, and the integrin-beta1 mechanisms proposed to underlie it.

PMID 40823151 | DOI 10.31491/apt.2024.12.158

Review 2020

The potential of GHK as an anti-aging peptide.

Dou Y et al - Aging pathobiology and therapeutics

A review of GHK as an anti-aging peptide noting that serum levels decline with age and that the skin remodelling and antioxidant evidence to date is from laboratory and animal studies.

Reported figure: serum GHK averaging 200 ng/ml at age 20 declining to an average of 80 ng/ml by age 60

PMID 35083444 | DOI 10.31491/apt.2020.03.014

Review 2018

Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data.

Pickart L et al - International journal of molecular sciences

The most widely cited modern review of GHK-Cu, summarising its reported regenerative and protective actions across skin, lung, bone, liver and stomach and the gene-expression data proposed to explain them.

PMID 29986520 | DOI 10.3390/ijms19071987

Review 2015

GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration.

Pickart L et al - BioMed research international

A narrative review of GHK in skin regeneration covering collagen and glycosaminoglycan synthesis, metalloproteinase modulation and reported cosmetic effects on skin density and wrinkles.

Reported figure: described as capable of up- and downregulating at least 4,000 human genes

PMID 26236730 | DOI 10.1155/2015/648108

Review 2012

The human tripeptide GHK-Cu in prevention of oxidative stress and degenerative conditions of aging: implications for cognitive health.

Pickart L et al - Oxidative medicine and cellular longevity

A narrative review arguing that GHK-Cu's antioxidant, anti-inflammatory and gene-regulating actions could be relevant to age-associated cognitive decline.

PMID 22666519 | DOI 10.1155/2012/324832

Review 2008

The human tri-peptide GHK and tissue remodeling.

Pickart L - Journal of biomaterials science. Polymer edition

A narrative review of GHK and GHK-Cu in tissue remodelling, listing chemoattractant, anti-inflammatory and matrix-protein effects and citing controlled studies on aged skin reporting tighter skin and reduced fine lines.

PMID 18644225 | DOI 10.1163/156856208784909435

How this library is built. Entries are located through PubMed searches for GHK-Cu, Copper Tripeptide-1, and the Pickart publication record, verified against the National Library of Medicine record, and summarized from the published abstracts. Summaries are deliberately conservative: they state what the paper reports, at the evidence level it reports it. Corrections are welcome and credited. Last updated August 2026. Maintained by MAXXING Editorial.