Animal onlyPreprint
This preclinical study investigated whether the endogenous copper-binding peptide GHK-Cu (glycyl-L-histidyl-L-lysine–copper complex) could mitigate age-related cognitive decline in middle-aged to old C57BL/6J mice (20–21 months). Two delivery routes were compared: short-term intraperitoneal (IP) administration over 5 days and longer-term intranasal (IN) administration over 8 weeks. Hippocampal-dependent spatial learning was assessed via an escape latency task; molecular changes were examined through hippocampal immunohistochemistry and bulk RNA sequencing, with differential gene expression analyzed using DESeq2 and gene set enrichment analysis (GSEA). Both delivery routes were associated with improved escape latency performance in treated mice of both sexes compared to controls, suggesting behavioral rescue of age-related learning deficits. However, the two routes produced divergent hippocampal transcriptomic profiles, implying that delivery method and exposure duration engage distinct molecular aging programs. Key limitations include the exclusive use of a mouse model, the absence of human data, variability in statistical power across outcome measures, and preprint status meaning the findings have not yet undergone formal peer review. The study does not establish causality in humans and is hypothesis-generating for future translational research.
Unknown journal · May 2026DOI ↗ Animal only
This study investigated whether GHK-Cu (the tripeptide Glycine-Histidine-Lysine complexed with copper, naturally found in human plasma and urine) could delay aging using the roundworm Caenorhabditis elegans as a model organism. The researchers measured lifespan, stress resistance (oxidative and thermal), physical function (motility, pharyngeal pumping, defecation rhythm), and markers of cellular aging such as lipofuscin and lipid accumulation. They also examined mitochondrial health and key longevity signaling pathways. The study found that GHK-Cu extended worm lifespan, improved multiple age-related functional measures, and reduced aging biomarkers. At the mechanistic level, GHK-Cu appeared to preserve mitochondrial function—maintaining membrane potential, reducing age-related mitochondrial fragmentation, promoting mitochondrial fusion (via regulation of drp-1 and fzo-1), and increasing ATP production. Additionally, GHK-Cu activated the DAF-16 and SKN-1 longevity pathways and upregulated downstream target genes including sod-3, gst-4, gcs-1, lys-7, and lys-8. A key limitation is that all experiments were conducted in C. elegans; whether these findings translate to mammals or humans remains unknown.
Biogerontology · May 2026DOI ↗ Animal only
This study investigated the anti-inflammatory and antioxidant properties of the bioactive tripeptide complex GHK-Cu (Glycyl-L-histidyl-L-lysine-Cu²⁺) using zebrafish larvae as an in vivo model. Researchers induced acute inflammation in larvae using either copper sulfate (CuSO₄) or lipopolysaccharide (LPS) and then assessed the effects of GHK-Cu treatment. According to the study, GHK-Cu notably reduced the migration of neutrophils and macrophages to sites of inflammation. It also suppressed the gene expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) while upregulating the anti-inflammatory cytokine IL-10. The compound was further reported to reduce markers of oxidative stress, including nitric oxide (NO) and reactive oxygen species (ROS), and to improve superoxide dismutase (SOD) activity. Pathway analysis suggested that GHK-Cu's effects may be mediated in part through downregulation of the JAK1 signaling pathway. The authors propose that these findings provide a theoretical basis for the use of GHK-Cu as a functional cosmetic ingredient. Key limitations include the use of a non-mammalian animal model and the absence of human or cell-culture mechanistic data, meaning clinical translation remains unestablished.
European journal of pharmacology · Apr 2026DOI ↗ Animal onlyPreprint
This mouse study investigated whether the endogenous copper-binding peptide GHK-Cu could improve age-related cognitive decline, and whether outcomes differed based on how the compound was delivered. Aged C57BL/6J mice (20–21 months old) received GHK-Cu either intraperitoneally (IP) for 5 days or intranasally (IN) for 8 weeks. Researchers assessed hippocampal-dependent spatial learning, along with hippocampal tissue markers and bulk RNA sequencing. Both delivery routes were associated with improvements in escape learning, though IN administration showed broader and more sustained benefits across both sexes, while IP dosing produced a more limited effect, primarily in males. Immunohistochemistry revealed route-dependent changes in markers of synaptic density (synaptophysin), neuroinflammation (GFAP, MCP-1, TGF-β), and cellular senescence (p21). Transcriptomic analysis showed striking divergence: IN treatment was associated with suppression of oxidative phosphorylation and MYC target pathways, while IP treatment activated stress-response, DNA repair, and mitochondrial metabolic pathways. The authors conclude that GHK-Cu can improve cognitive outcomes through mechanistically distinct biological programs depending on the route and duration of administration. Key limitations include use of a single rodent strain, lack of human data, and preprint status (not yet peer-reviewed).
Unknown journal · Apr 2026DOI ↗ Animal only
This study introduced a Golgi-targeted copper delivery system (LNP-ATOX1/GHK-Cu@PCL-GelMA) designed to enhance the activity of copper-dependent proteins—particularly lysyl oxidase (LOX)—to promote fascia regeneration. The system combined GHK-Cu (a copper-peptide complex) as a sustained-release copper source with lipid nanoparticles (LNPs) delivering mRNA encoding ATOX1, a copper chaperone that shuttles copper into the Golgi apparatus via ATP7A/B transporters. In vitro experiments showed the system significantly increased Golgi copper accumulation, raised LOX activity to approximately 1.78 times that of controls, and enhanced angiogenic capacity. The researchers also reported that ATOX1 upregulation promoted copper-dependent translocation of ATP7A and Rac1 to the plasma membrane, potentially supporting neovascularization. In a rabbit fascia defect animal model, the strategy improved collagen alignment, neovascularization, and extracellular matrix reconstruction. Limitations include the absence of human or large-animal data, reliance on a single animal model, and the translational gap between rabbit fascia repair and human clinical outcomes. No human trials were conducted.
Journal of controlled release : official journal of the Controlled Release Society · Dec 2025DOI ↗ Animal only
This study investigated the therapeutic potential of GHK-Cu (glycyl-l-histidyl-l-lysine-copper) in ulcerative colitis (UC) using a dextran sulfate sodium (DSS)-induced mouse model and complementary cell-based experiments. Researchers administered GHK-Cu to BALB/c mice with DSS-induced colitis and assessed disease activity, colon histology, goblet cell counts, tight junction proteins (ZO-1, Occludin), inflammatory cytokines (TNF-α, IL-6, IL-1β), and key signaling proteins (SIRT1, STAT3, p-STAT3, RORγt). Network pharmacology and molecular docking were used to predict SIRT1 as a core target. A co-culture model of mouse colonic epithelial cells (MCECs) and peritoneal macrophages confirmed GHK-Cu's role in mucosal healing. STAT3 silencing via siRNA revealed that STAT3 is required for GHK-Cu's promotion of epithelial healing and tight junction protein upregulation, but not for its anti-inflammatory effects, suggesting additional pathways are involved. The study found that GHK-Cu reduced disease severity, suppressed inflammation, enhanced mucosal repair via the SIRT1/STAT3 pathway, and decreased RORγt expression, suggesting reduced Th17 cell activity. Limitations include exclusive use of animal and in vitro models with no human data.
Frontiers in pharmacology · Jul 2025DOI ↗ Animal only
This study investigated whether the naturally occurring copper-binding peptide GHK-Cu (glycyl-L-histidyl-L-lysine copper complex) could reduce Alzheimer's disease (AD)-related pathology in a transgenic mouse model. Male and female 5xFAD mice — a well-established preclinical model of AD — were treated with intranasal GHK-Cu three times per week from 4 to 7 months of age, with a C57BL/6J background strain as context. The researchers assessed behavioral outcomes, amyloid plaque burden, and neuroinflammation markers. The study found that treated mice showed delayed cognitive impairment compared to untreated controls, along with reductions in amyloid plaques and lower levels of MCP1-associated inflammation in the frontal cortex and hippocampus. The authors suggest these findings justify further investigation of GHK-Cu as a potential AD therapeutic. Key limitations include the exclusively preclinical (animal) nature of the work — results in transgenic mouse models do not reliably predict outcomes in humans — and the fact that 5xFAD mice represent an aggressive, artificially accelerated form of amyloid pathology that may not fully reflect the complexity of human AD.
Aging pathobiology and therapeutics · Sep 2024DOI ↗