GHK-Cu Explained: The Copper Peptide (GHK Copper) — Structure, Chemistry and Research Overview

Names and historical context

GHK-Cu names a copper-associated tripeptide composed of glycine, histidine, and lysine with copper(II). The letter sequence GHK is a one-letter representation of those three amino-acid residues. Common names include GHK copper, copper tripeptide-1, and copper peptide. These labels appear in different cataloguing and technical contexts, so a specification should identify the actual composition rather than rely on a familiar synonym alone.

The GHK sequence was first described by Loren Pickart in 1973. In chemical writing, GHK-Cu is a compact name for a coordination complex, not a fourth amino acid or a covalent extension of the peptide sequence. The notation ·Cu(II) makes the metal association explicit. Careful nomenclature distinguishes the peptide ligand from the copper-containing complex and avoids implying a fixed structure beyond what a particular analytical record establishes.

Sequence and composition

The peptide ligand has the sequence Gly-His-Lys, abbreviated GHK. Its component residues differ in side-chain chemistry: glycine has a hydrogen side chain, histidine contains an imidazole group, and lysine has a terminal amino-bearing side chain. The order matters when identifying the molecule; GHK is not interchangeable with another arrangement of the same residue names.

The stated product identity is Gly-His-Lys·Cu(II), with molecular formula C14H24N6O4Cu and approximate molecular weight 403.9 g/mol. The copper association is part of the stated material identity. Formula and mass are useful cross-checks in technical documentation, but they do not substitute for lot-specific measurement. Hydration, counter-ion accounting, and the conventions used to report a complex can affect how analytical values are presented.

Coordination chemistry in brief

Copper(II) is a transition-metal ion that can form coordination bonds with donor atoms in a ligand. In GHK-Cu, the peptide provides potential donor sites, including atoms associated with the histidine imidazole and peptide backbone. The exact coordination description depends on chemical conditions and the structural method used. A concise product name does not, by itself, specify every bond distance, geometry, or solution-state arrangement.

Coordination compounds are often described by considering the metal center, ligand identity, donor atoms, and overall charge balance. For a research record, it is useful to report the GHK sequence, copper oxidation state as Cu(II), the formula convention, and any counter-ion or hydration information supplied by the analytical record. These details make comparison between certificates and reference literature more transparent.

Appearance and supplied form

Copper-containing complexes can display color because electronic transitions involving the metal center absorb portions of visible light. The observed shade may depend on coordination environment, concentration, solid-state packing, lighting, and material condition. Color is therefore a descriptive observation, not an identity test: a photograph or visual inspection cannot establish sequence, copper content, or purity.

The NF7 GHK-Cu product is supplied as 50 mg of lyophilized powder in a sealed glass vial. Lyophilization removes water under controlled processing conditions to produce a dry solid. The vial remains sealed for storage and shipment. Lot-specific documentation should be consulted for the reported identity and analytical results; appearance alone cannot confirm that a particular lot matches its specification.

Analytical characterization

Reverse-phase high-performance liquid chromatography (HPLC) can separate peptide-related components and provide a chromatographic profile under a stated method. A reported peak-area percentage is method-dependent and should be read alongside the column, mobile phase, detector, integration approach, and system suitability information when provided. Chromatographic area is not automatically equivalent to mass fraction or total peptide content.

Mass spectrometry, including liquid chromatography–mass spectrometry (LC-MS), can support identity assessment by comparing measured ions with expected molecular mass. Matrix-assisted laser desorption/ionization (MALDI) is another mass-analysis approach. Copper-containing samples may show isotope patterns and ion forms that require interpretation. A strong report links the observed data to the proposed composition and identifies the method used rather than presenting an isolated number.

Amino-acid analysis can provide residue-composition information after suitable sample preparation, while elemental or metal-focused methods may be used to examine copper content. No single method answers every question. A practical analytical package combines complementary measurements, states limitations, and distinguishes identity, chromatographic profile, peptide content, and metal association as separate attributes.

Reading lot documentation

A certificate of analysis (COA) should identify the material and lot, connect results to test methods, and make clear which values are specifications and which are observations. Check that the product name and lot identifier correspond to the vial label. Review analytical dates, units, acceptance criteria where listed, and any notes on sample preparation or reporting conventions.

The NF7 COA is lot-matched and can be checked through the site’s Verify a lot page. Traceability is strongest when the physical label, order record, and COA display the same lot identifier. Retain the associated documentation with laboratory records so that later review can identify the supplied material and the analytical basis for its stated attributes.

Storage and shipping notes

Store the sealed, lyophilized vial at 2–8 °C, protected from light and moisture. Keep the closure intact and use a dry storage location with suitable temperature monitoring. Before opening the outer packaging, allow a sealed vial to equilibrate to room temperature; this reduces the chance of moisture condensing on a cold container. Do not open the vial until it has reached the intended handling environment.

Products ship within the United States using cold-chain packaging. On receipt, inspect the package and vial, record the lot identifier, and transfer the sealed material to the stated storage conditions. Shipment documentation and the lot-matched COA provide complementary records: one describes custody and shipment, while the other records material identity and analytical information.

A short receiving checklist for GHK-Cu

When a GHK-Cu shipment arrives, a consistent intake routine keeps records aligned with the physical vial. Confirm that the outer cold-chain packaging is intact, that the vial seal is unbroken and that the label states 50 mg, the product name and a lot number. Record the arrival date and the condition of any temperature-control materials in the parcel.

Next, enter the lot number on the Verify a lot page and save a copy of the Certificate of Analysis alongside the receiving record. Compare the reported mass spectrometry result with the expected molecular weight of approximately 403.9 g/mol, note the HPLC purity figure and transfer the sealed vial to 2–8 °C storage away from light.