Research compound overview
GHK-Cu research peptide: copper-peptide chemistry, lab context and quality standards
GHK-Cu is a copper-binding tripeptide used in biochemistry and cell culture research. This guide explains what it is, how it is studied in the laboratory, and what to look for in the analytical documentation of any research-grade lot.
GHK-Cu at a glance
The table below summarizes the identifying details researchers usually confirm before designing an experiment. All values describe the chemical material, not any use outside the laboratory.
| Compound | GHK-Cu (copper(II) glycyl-L-histidyl-L-lysine) |
|---|---|
| Peptide sequence | Gly-His-Lys (three amino acids) |
| CAS number | 89030-95-5 |
| Free tripeptide mass | about 340.4 g/mol (GHK, without copper) |
| Physical form | Lyophilized solid, typically blue to blue-violet because of the copper(II) center |
| Typical documentation | HPLC purity, mass spectrometry identity, lot number, third-party testing |
| Intended use | Qualified laboratory research only |
What is GHK-Cu?
GHK is a naturally occurring tripeptide first described in the early 1970s after it was isolated from human plasma albumin. Its defining chemical feature is a strong affinity for copper(II). When the peptide binds the metal, it forms the GHK-Cu complex, a well-characterized coordination compound that has been examined in a large body of in vitro literature.
Because the peptide is short and its copper binding is well defined, GHK-Cu is a convenient model for studying metal-peptide coordination, redox behavior and the way small copper complexes behave in cell culture media. Synagenics supplies it as a lyophilized research material for exactly this kind of bench work.
Copper-peptide coordination chemistry
In the GHK-Cu complex, copper(II) is held by the peptide in a compact square-planar arrangement. The imidazole nitrogen of the histidine side chain, the amino terminus and the deprotonated backbone amide nitrogens all participate in binding. This multidentate arrangement is what gives the complex its stability and its characteristic color.
Spectroscopic methods are the standard way to characterize that binding. UV-visible absorbance shows the d-d transition of the copper center, circular dichroism reports on the chiral environment of the complex, and electron paramagnetic resonance (EPR) probes the copper(II) coordination geometry directly. Mass spectrometry confirms the intact peptide, and the copper isotope pattern can be used to confirm that the metal is present.
Why the metal-bound form matters
Free GHK and GHK-Cu are different chemical species, and published work consistently treats them as such. Design experiments so the copper-free peptide and a free copper salt appear as separate controls. That is the only way to separate an effect of the peptide itself from an effect of the metal or of the intact complex.
Areas of laboratory research
The literature on GHK-Cu spans several experimental areas. The groupings below describe the model systems used, not any application beyond the laboratory.
Cell culture models
Fibroblast and other adherent cell lines are the most common in vitro systems. Researchers use them to examine how the complex behaves in defined media and how cultured cells respond over time.
Gene expression analysis
Transcript-level studies in cultured cells look at extracellular matrix related genes and other panels, usually by quantitative PCR or RNA sequencing with matched controls.
Redox and antioxidant assays
Cell-free and cell-based assays examine how copper-peptide complexes behave in oxidative environments and how they compare with free copper.
Common experimental systems
- Cultured cell lines in defined, serum-controlled media
- Cell-free biochemical and enzyme assays
- Spectroscopic characterization of copper binding (UV-vis, CD, EPR)
- Chromatographic comparison of lots by reversed-phase HPLC
- Mass spectrometric identity and isotope-pattern confirmation
Designing a clean in vitro experiment
Good controls matter more than any single reagent choice. The points below are the ones that most often decide whether a copper-peptide experiment can be interpreted.
- Run the right controls. Include a vehicle control, a copper-free GHK control and a free copper control at matched copper concentration.
- Mind the medium. Serum, amino acids and buffer components can bind copper and compete with the peptide, so record the exact medium composition and keep it constant across arms.
- Control pH and buffer. Coordination geometry and color shift with pH, and some buffers coordinate copper themselves.
- Use documented lots. Keep the lot number with every dataset and, where possible, repeat a key result with a second lot.
- Check for contaminants. Residual counter-ions and trace impurities can influence cell assays, which is another reason the analytical report matters.
- Replicate independently. Biological replicates on separate days are more informative than many technical wells in one run.
Analytical characterization standards
A research peptide is only as useful as the documentation behind it. Research-grade GHK-Cu should arrive with a report that lets you verify, not assume, what is in the vial.
- HPLC purity. Reversed-phase HPLC reports the main peak as a percentage of total integrated area. Review the chromatogram itself, not only the headline number.
- Mass spectrometry identity. The observed mass should match the expected value for the intact peptide, with the copper isotope pattern where relevant.
- Lot tracking. A lot number ties the report to the exact material you receive.
- Independent third-party testing. Results produced outside the manufacturer add credibility.
The Certificate of Analysis library shows how we document the lots that have been tested.
How to evaluate any research peptide supplier
The same checklist applies to every vendor, including us. It takes a few minutes and prevents most sourcing problems.
1. Ask for the data
A real report shows the chromatogram, the mass spectrum, the lot number and the date. A single line reading “99%” is not a report.
2. Match the lot
The lot printed on the vial label must match the lot on the report. If it does not, the report does not describe your material.
3. Look for consistency
Reports from several lots of the same compound should look alike. Large, unexplained swings between lots are a warning sign.
Our own quality standards and the story behind them in From Our Lab explain how we apply this checklist to every lot we release.
Selected published literature
These PubMed records describe in vitro and biochemical work on GHK and its copper complex. They are provided for scientific context only.
Background and history of copper-peptide research
Interest in GHK began in the early 1970s, when researchers working with human plasma albumin identified a small copper-binding peptide fraction. Over the following decades the tripeptide and its copper complex were synthesized, characterized and compared with related copper-binding motifs. Because the sequence is short, it can be produced reliably by solid-phase peptide synthesis and purified by preparative HPLC, which makes it practical to supply as a defined, reproducible research material.
Today the compound appears in the literature mainly as a model for metal-peptide chemistry and as a reference reagent in cell culture work. Reviews of the field tend to stress two practical lessons for bench scientists. First, the identity and purity of the material must be documented lot by lot. Second, the experimental design must separate the effect of the peptide, the metal and the intact complex.
A simple lot-review workflow
- Open the Certificate of Analysis for the lot number printed on your vial.
- Confirm the compound name, lot number and test date match your order.
- Inspect the HPLC trace for a single dominant peak and a clean baseline.
- Compare the observed mass in the spectrum with the expected mass of the intact peptide.
- Record the lot number in your lab notebook next to every dataset that uses it.
Following the same steps for every compound and every lot builds a traceable record, which is what makes results reproducible months later and comparable between laboratories.
GHK-Cu research FAQ
What is GHK-Cu?
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (Gly-His-Lys). In the laboratory it is used as a defined copper-peptide coordination compound in biochemical assays, spectroscopy and cell culture research models.
Is GHK-Cu sold for human or animal use?
No. Synagenics supplies GHK-Cu strictly as a research-use-only material for qualified laboratory work. It is not a drug, supplement or cosmetic, and nothing on this page is a claim about use in people or animals.
How is the purity of research-grade GHK-Cu verified?
Purity is normally reported by reversed-phase HPLC as a percentage of the main peak, and identity is confirmed by mass spectrometry. Each lot should also carry a lot number so the analytical report can be matched to the exact material received.
Where can I see a Certificate of Analysis?
Certificates for tested lots are published in the public Certificate of Analysis library at synagenics.com/coas/, where you can review the chromatogram and mass spectrum for each report.
Why does copper content matter in GHK-Cu experiments?
The biological and chemical behavior of the peptide depends on whether copper is bound. Researchers often run copper-free GHK and free copper controls beside the complex so that effects can be attributed to the correct species.
Which cell culture systems are commonly used?
Published in vitro work commonly uses fibroblast cultures and other adherent cell lines, alongside cell-free redox and spectroscopic assays. The selected PubMed records below show representative experimental designs.
Related research
Continue exploring the Synagenics research library.
Need research-grade GHK-Cu?
Browse the open certificate of analysis library to see how we document tested lots.
For qualified laboratory research use only. Not for human or animal use. These statements have not been evaluated by the US Food and Drug Administration.