GHK-Cu Copper tripeptide-1

What is GHK-Cu?

GHK is the tripeptide Gly-His-Lys. Loren Pickart reported it in human serum in 1973, and in 1980 showed that it co-purifies with copper and readily forms copper(II) complexes. The copper ion sits between the histidine imidazole nitrogen and the N-terminal amine, and it is the complex, GHK-Cu, rather than the bare peptide that most of the literature studies. The blue colour of a GHK-Cu solution comes from that bound copper.

The same Gly-His-Lys triplet occurs inside larger proteins, including the alpha-2 chain of type I collagen and SPARC, which is why early researchers suggested it could be released from collagen at sites of tissue damage. In cosmetics the complex is listed under the INCI name “copper tripeptide-1”; this product is a lyophilised research reference material, not a serum or cream.

GHK-Cu identity

Registries describe GHK-Cu with more than one copper stoichiometry: the FDA substance record (GSRS UNII 6BJQ43T1I9) is the 1:1 complex used above, while PubChem also holds a 2:1 record (C₂₈H₄₈CuN₁₂O₈) titled “GHK-Cu”. A 2026 review notes that published work often does not say which form it tested.

Certificates for the current lots

Each size is filled from its own lot and analysed separately by ILS Laboratories in San Diego, which states ISO/IEC 17025 accreditation for activities within its published scope:

Published research on GHK-Cu

• Discovery (1973). Pickart’s first report described a tripeptide in human serum that prolonged survival of normal liver cells in culture; it was identified as glycyl-histidyl-lysine in 1977. Tripeptide in human serum which prolongs survival of normal liver cells and stimulates growth in neoplastic liver. Pickart L, Thaler MM. Nature New Biology, 1973.
• Copper binding (1980). The plasma tripeptide co-purified with roughly equimolar copper, readily formed copper(II) complexes and increased copper uptake into cultured hepatoma cells. Growth-modulating plasma tripeptide may function by facilitating copper uptake into cells. Pickart L, et al. Nature, 1980.
• Collagen synthesis in fibroblasts (1988). GHK-Cu stimulated collagen synthesis by cultured fibroblasts from picomolar concentrations, peaking at nanomolar, without changing cell number. Stimulation of collagen synthesis in fibroblast cultures by the tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu2+. Maquart FX, et al. FEBS Letters, 1988.
• Wound-chamber model (rats, 1993). In implanted wound chambers, GHK-Cu produced concentration-dependent increases in collagen, glycosaminoglycans and total protein, with type I and III collagen mRNA rising; a control tripeptide had no significant effect. 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. Journal of Clinical Investigation, 1993.
• Gene-expression signature (2012). Using lung tissue from smokers with COPD and the Connectivity Map, researchers identified GHK as a compound predicted to reverse an emphysema-related gene signature, and in fibroblasts from COPD lungs it restored collagen gel contraction. A gene expression signature of emphysema-related lung destruction and its reversal by the tripeptide GHK. Campbell JD, et al. Genome Medicine, 2012.
• Topical human trials (1992–2006). Randomised trials of topical GHK-Cu products are few and mixed: a positive result in diabetic neuropathic ulcers, no difference from placebo in venous ulcers, and no objective difference in a 13-patient study after laser resurfacing. Mulder GD, et al., 1994; Bishop JB, et al., 1992; Miller TR, et al., 2006.
• Reviews (2018, 2026). Pickart and Margolina relate GHK’s range of reported actions to gene-expression data; a 2026 evidence-mapping review concludes that preclinical data are consistent but clinical evidence remains sparse. 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, 2018; GHK-Cu as a Bioactive Metallopeptide and Drug-Delivery Cargo. Mateescu DM, et al. Pharmaceutics, 2026.

Regulatory status

GHK-Cu is not an approved drug. FDA placed “GHK-Cu (for injectable routes of administration)” in its compounding safety-risk category in 2023; the page now lists it among nominated-but-withdrawn substances. GHK-Cu for non-injectable routes is under FDA evaluation for the compounding list. As copper tripeptide-1 it is used as a cosmetic ingredient. FDA compounding safety-risk list. Clean Peptide’s GHK-Cu is a laboratory reference material only.

Related research

• KLOW: GHK-Cu blended with BPC-157, TB-500 and KPV in one vial.
• GLOW peptide blend: what is in GHK-Cu / BPC-157 / TB-500 blends and how they compare with KLOW.
• BPC-157, TB-500 and KPV as single peptides.
• Copper peptides in the catalogue.