Glycyl-L-histidyl-L-lysine copper (GHK-Cu) is a naturally occurring tripeptide-copper complex with potent regenerative properties, discovered in human plasma where levels decline from ~200 ng/mL in youth to ~80 ng/mL by age 60, correlating with reduced healing capacity
Glycyl-L-histidyl-L-lysine copper (GHK-Cu) is a naturally occurring tripeptide-copper complex with potent regenerative properties, discovered in human plasma where levels decline from ~200 ng/mL in youth to ~80 ng/mL by age 60, correlating with reduced healing capacity (1,2).
Origins and Discovery
Isolated in 1973 by Pickart from human plasma, GHK was noted for rejuvenating protein synthesis in aged liver tissue (1). It chelates Cu²⁺ tightly, forming GHK-Cu found in plasma, saliva, and urine, with levels dropping alongside regenerative decline (2).
Structural Chemistry
X-ray crystallography reveals tetragonal Cu²⁺ coordination via histidine’s imidazole N, glycine’s α-amino N, and Gly-His amide N, stabilizing copper against redox cycling and aiding delivery to lysyl oxidase and superoxide dismutase (2,3).
Endogenous Signaling
Tissue injury releases GHK from collagen type I and SPARC-derived KGHK fragments, signaling “danger” to promote timed angiogenesis (4). This copper-rich alarm initiates repair then self-limits via genomic shifts (1).
Genomic Reprogramming
Connectivity Map analysis shows GHK-Cu (1-10 nM) alters 31% of genes ≥50% in 24 hours, upregulating angiopoietin-1, stathmin-3, KCND1, and downregulating pro-fibrotic NOTCH3, “resetting” cells to healthier states (1,2).
Skin Regeneration and Wound Healing
Topical GHK-Cu (0.01-100 nM) boosts collagen I/III, elastin, decorin, and bFGF by 230% in fibroblasts (3). A 12-week trial showed 55.8% wrinkle reduction; diabetic rat wounds healed 9-fold faster with less TNF-β/MMP-9 (3). RADA16-I hydrogels enhanced proliferation and closure without cytotoxicity (5).
Hair Follicle Biology
GHK-Cu hydrogels stimulate follicle growth, enlarge diameter, enhance Wnt signaling in dermal papilla, and preserve stem markers K15/p63 (3).
Angiogenesis and VEGF
GHK-Cu delivers copper, inducing VEGF mRNA in 10 minutes to accelerate neovascularization (6).
Anti-Inflammatory and Antioxidant Effects
GHK-Cu quenches UV-induced lipid peroxidation (4-HNE, MDA) better than SOD, binds acrolein/glyoxal, and raises glutathione/ascorbate in wounds (2,7).
Anti-Fibrotic and Organ Protection
Mitigates bleomycin lung fibrosis via TGF-β/Smad suppression; corrects 70% age-dysregulated genes in COPD fibroblasts (1,2).
Neurotrophic Potential
GHK-Cu conduits increase axonal regeneration, Schwann proliferation, and NGF/NT-3/NT-4 in rat sciatic nerves, modulating >600 neuronal transcripts (3).
Safety and Formulations
No cytotoxicity up to 100 µM; caution in copper overload (e.g., Wilson’s disease) due to Fenton risk (2). Stabilize via nano-lipids, PEGylation, or scaffolds against carboxypeptidase (3).
References
- Pickart L, Margolina A. Regenerative and protective actions of the GHK-Cu peptide in the light of new gene data. Int J Mol Sci. 2018;19(7):1987. doi:10.3390/ijms19071987
- Pickart L, Vasquez-Soltero JM, Margolina A. GHK peptide as a natural modulator of multiple cellular pathways in skin regeneration. BioMed Res Int. 2015;2015:648108. doi:10.1155/2015/648108
- Margolina A, Pickart L. The human tripeptide GHK-Cu in prevention of oxidative stress and inflammation. BioMed Res Int. 2012;2012:324832.
- Sage EH, et al. SPARC-derived peptides modulate dermal angiogenesis. Front Cell Dev Biol. 2019;7:269. doi:10.3389/fcell.2019.00269
- Dzierżyńska M, et al. Release systems based on self-assembling RADA16-I hydrogels functionalized with GHK peptide. Sci Rep. 2023;13:6273. doi:10.1038/s41598-023-33464-w
- Sen CK, et al. Copper-induced vascular endothelial growth factor expression and wound healing. Am J Physiol Heart Circ Physiol. 2002;282(5):H1821-H1827. doi:10.1152/ajpheart.01015.2001
- Pickart L. The human tripeptide GHK and tissue remodeling. J Biomater Sci Polym Edn. 2008;19(8):969-988.