GHK-Cu — Glycyl-L-Histidyl-L-Lysine Copper Complex | Naturally Occurring Tissue-Remodeling Tripeptide
Research-Grade Compound
GHK-Cu (glycyl-L-histidyl-L-lysine copper complex) is a naturally occurring copper-binding tripeptide found in human blood plasma, saliva and urine. Molecular formula C14H24CuN6O4, molecular weight 403.9 Da as the copper complex — 340.4 Da for the free tripeptide without copper. CAS 89030-95-5.
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In-depth research overview, mechanism of action, and study applications.
This Certificate of Analysis was issued by an independent third-party laboratory. Peptide.Express does not conduct in-house testing. Results are provided as-is from the testing facility and confirm batch identity, purity, and analytical methodology. For questions about specific CoA results, contact [email protected].
What is GHK-Cu?
GHK-Cu (glycyl-L-histidyl-L-lysine copper complex) is a naturally occurring copper-binding tripeptide found in human blood plasma, saliva and urine. Molecular formula C14H24CuN6O4, molecular weight 403.9 Da as the copper complex — 340.4 Da for the free tripeptide without copper. CAS 89030-95-5.
Endogenous plasma concentrations are roughly 200 ng/mL at age 20, falling to around 80 ng/mL by age 60. Whether that decline drives any of the age-related changes in wound healing kinetics is still an open question — the correlation is well documented, the causation is not. But it is why the compound sits at the centre of regenerative aging research rather than being treated as a curiosity.
It is often called the "beauty peptide" in research and consumer contexts because of its effects on fibroblast activity and collagen synthesis. The nickname undersells it. GHK-Cu is a copper courier as much as it is a signaling peptide, and separating those two roles is what most of the interesting mechanistic work is about.
How Does GHK-Cu Work? Mechanism of Action
GHK-Cu functions as a biological courier. It binds Cu²⁺ and delivers it to copper-dependent enzymes responsible for connective tissue synthesis and remodeling. Strip the copper out and much of the activity goes with it — which is why research protocols distinguish GHK from GHK-Cu rather than treating them as the same molecule.
The primary signaling mechanism runs through fibroblasts. GHK-Cu stimulates dermal fibroblasts to upregulate collagen production through direct effects on collagen gene transcription. Alongside this it activates matrix metalloproteinases 1 and 2, which clear cross-linked and damaged collagen from the extracellular matrix.
Those two actions running together is the part worth understanding. Upregulating collagen synthesis alone would produce accumulation — more matrix, not better matrix. Simultaneous MMP activation means the net result studied in cell culture is turnover: damaged collagen out, newly synthesised collagen in. Tissue renewal rather than tissue thickening.
The copper-delivery arm is mechanistically distinct. GHK-Cu is proposed to supply bioavailable copper to lysyl oxidase, the copper-dependent enzyme that crosslinks collagen and elastin fibrils. Without that crosslinking step, newly deposited matrix lacks tensile integrity. This is the clearest case in the compound's pharmacology where the metal, not the peptide, is doing the work.
A secondary antioxidant mechanism has been characterised: GHK-Cu scavenges reactive oxygen species and upregulates superoxide dismutase activity, protecting cells from UV-induced oxidative damage in culture. In hair follicle research it is studied for effects on follicular inflammation and dermal papilla cell activity — an area where the mechanistic evidence is thinner than the marketing around it suggests.
Research Applications of GHK-Cu
Extracellular Matrix and Collagen Research
- Fibroblast collagen expression assays: Type I and Type III collagen transcription is the primary quantitative endpoint, typically measured over 8–12 weeks of exposure in culture.
- Matrix metalloproteinase activity: MMP-1 and MMP-2 activation is what distinguishes GHK-Cu-driven remodeling from simple collagen accumulation.
- Lysyl oxidase function: copper-dependent crosslinking assays link the metal-delivery mechanism to measurable matrix tensile properties.
Oxidative Stress and Aging Models
- Reactive oxygen species scavenging: direct antioxidant activity measured independently of the collagen pathway.
- Superoxide dismutase upregulation: an enzymatic readout that separates induced antioxidant defence from direct radical quenching.
- UV-damage protection models: keratinocyte and fibroblast cultures exposed to controlled UV dose, with viability and matrix integrity as endpoints.
Delivery Route and Formulation Research
- Topical versus injectable comparison: the two routes produce very different tissue exposure profiles, and most published skin data is topical while most peptide-research protocols are not.
- Copper loading studies: GHK versus GHK-Cu head-to-head, isolating the contribution of the metal from the contribution of the peptide.
- Multi-peptide blend behaviour: GHK-Cu is a component of both the KLOW and GLOW formulations, where its stability alongside other peptides is a formulation question in its own right.
Topical vs Injectable GHK-Cu in Research
| Feature | Topical GHK-Cu | Injectable GHK-Cu |
|---|---|---|
| Typical research context | Dermal / skin-model studies | Systemic and connective tissue models |
| Tissue exposure | High local, minimal systemic | Systemic distribution |
| Published evidence volume | Larger — most GHK-Cu skin data is topical | Smaller and more mechanistic |
| Penetration variable | Stratum corneum barrier is the limiting factor | Not applicable |
| Typical formulation | Serum or cream at low concentration | Reconstituted lyophilized powder |
| Copper delivery efficiency | Dependent on vehicle and barrier penetration | Direct |
This distinction gets glossed over constantly. A study showing topical GHK-Cu improves a dermal endpoint says very little about what the same compound does when introduced systemically, because the rate-limiting step in the topical case is a barrier that does not exist in the injectable case. Match the route in your protocol to the route in the literature you are citing.
GHK-Cu Technical Specifications
| Compound Name | Glycyl-L-histidyl-L-lysine copper(II) complex |
|---|---|
| Common Synonyms | GHK-Cu, copper peptide, Cu-GHK, copper tripeptide-1, GHK copper |
| CAS Number | 89030-95-5 (copper complex); 49557-75-7 (GHK free tripeptide) |
| Molecular Formula | C14H24CuN6O4 |
| Molecular Weight | 403.9 Da (copper complex); 340.4 Da (free tripeptide) |
| Amino Acid Count | 3 (Gly-His-Lys) |
| Amino Acid Sequence | Gly-His-Lys coordinated with Cu²⁺ |
| Purity | ≥99% by HPLC |
| Purity Confirmation | LC-MS/MS molecular weight verification |
| Endotoxin Testing | LAL (Limulus Amebocyte Lysate) method |
| Physical Form | Lyophilized powder |
| Appearance | Deep blue powder — the Cu(II) coordination complex is the source of the colour |
| Reconstitution | Bacteriostatic water or sterile water |
| Storage (lyophilized) | -20°C, desiccated, protected from light |
| Storage (reconstituted) | 2–8°C, use within 14–28 days |
| Shelf Life | 24 months from manufacture (lyophilized) |
| Testing Methods | HPLC, LC-MS/MS, LAL Endotoxin |
| Documentation | Certificate of Analysis (CoA) per batch |
| FDA Status | Not approved for human therapeutic use |
| Intended Use | In-vitro laboratory research only |
How to Reconstitute GHK-Cu for Research
GHK-Cu is the one compound in this catalog where a coloured solution is correct rather than a warning sign. The copper complex gives a deep blue solution, and the depth of that blue tracks concentration. What you are checking for is cloudiness and particulate matter, not colour — and a solution that has gone pale or colourless is a signal that the copper coordination may have been disrupted.
- Allow the vial to reach room temperature before opening.
- Draw the calculated volume of bacteriostatic water. For the 50 mg vial, 5 mL yields 10 mg/mL and 10 mL yields 5 mg/mL.
- Swab the vial septum with alcohol and allow 30 seconds to dry.
- Inject the diluent slowly against the inner vial wall rather than onto the lyophilized cake.
- Swirl gently for 60–90 seconds. Do not shake — mechanical agitation of a metal-coordinated peptide risks disrupting the complex.
- Confirm a clear, deep blue solution. Blue colour is expected and correct. Discard if cloudy, if particulate matter is present, or if the solution is pale or colourless.
- Label with reconstitution date and concentration, and store protected from light — the copper complex is photosensitive.
- Store at 2–8°C and use within 14–28 days. Avoid repeated freeze-thaw cycles.
Diluent: bacteriostatic water for peptide reconstitution. Full protocol: step-by-step peptide reconstitution guide. Concentration maths: peptide reconstitution calculator.
Frequently Asked Questions — GHK-Cu
What does a GHK-Cu peptide do?
What is the difference between GHK and GHK-Cu?
What is GHK-Cu's role in collagen synthesis?
Why is GHK-Cu solution blue?
What are the research considerations around copper with GHK-Cu?
What is the difference between topical and injectable GHK-Cu research?
Does GHK-Cu affect hair follicle research?
Is GHK-Cu part of the KLOW or GLOW peptide blends?
Can GHK-Cu be studied alongside BPC-157 or TB-500?
Is GHK-Cu worth the attention it gets in longevity research?
What purity standard does Peptide.Express use for GHK-Cu?
What testing does GHK-Cu undergo before shipping?
How should GHK-Cu be stored before and after reconstitution?
How do I reconstitute GHK-Cu?
Where is the Certificate of Analysis for GHK-Cu?
Research References
- Pickart L, Margolina A. "Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data." International Journal of Molecular Sciences, 2018. Read the GHK-Cu regenerative gene-data review on PMC
- Pickart L, Vasquez-Soltero JM, Margolina A. "The Human Tripeptide GHK-Cu in Prevention of Oxidative Stress and Degenerative Conditions of Aging." Oxidative Medicine and Cellular Longevity, 2012. Read the GHK-Cu oxidative stress and aging review on PMC
- Review of GHK as an anti-aging peptide, covering the plasma decline observation and the tissue-remodeling gene expression data. Read the GHK anti-aging peptide review on PMC
- Maquart FX, Pickart L, Laurent M, Gillery P, Monboisse JC, Borel JP. "Stimulation of Collagen Synthesis in Fibroblast Cultures by the Tripeptide-Copper Complex Glycyl-L-Histidyl-L-Lysine-Cu2+." FEBS Letters. 1988. Read the Maquart 1988 GHK-Cu fibroblast collagen synthesis study
All products are sold for in-vitro laboratory research use only. Not intended for human consumption, clinical use, or veterinary use. Peptide.Express makes no medical claims. Consult the published literature for research application guidance.