Research compound reference

GHK-Cu

GHK-Cu is a copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (GHK). The material is a blue lyophilized (freeze-dried) solid of 99% or greater purity by HPLC, with a lot-specific Certificate of Analysis, for in vitro laboratory research. This page is a technical reference to the material's identity, chemistry, analytical testing and laboratory handling.

For research use only. Not for human or veterinary, diagnostic or therapeutic use.

The peptide and its metal

Three L-amino acids, read from the free amino end (N-terminus) to the free carboxylic acid end (C-terminus), with one copper(II) ion per peptide in the reference record used on this page.¹

1GGly

2HHis

3KLys

ionCuCopper(II)

H-GHK-OH with Cu(II)

Imidazole side chain (His) Basic side chain (Lys) Copper(II) ion Other residues

Schematic of composition only. It does not show how the copper ion is bound.

What is GHK-Cu?

GHK-Cu is a coordination complex: the tripeptide glycyl-L-histidyl-L-lysine bound to a copper(II) ion. The copper-free peptide, GHK, is catalogued under CAS 49557-75-7 and PubChem CID 73587, with the formula C₁₄H₂₄N₆O₄ and a molecular weight of 340.38 g/mol.²

The reference record cited by the Oasis Labs specification is PubChem CID 139035031, a 1:1 copper complex with the formula C₁₄H₂₁CuN₆O₄⁻ and a molecular weight of 400.90 g/mol.¹ That record describes the complex ion; the salt form and counter-ion of the solid are not specified, and lot identity is confirmed on the Certificate of Analysis.⁴ The material described on this page is a synthetic peptide complex intended as a laboratory reagent.

3residues

400.90g/mol, reference record¹

≥99%purity by HPLC, per lot

Composition

The peptide has three residues: glycine, histidine and lysine. Histidine carries an imidazole ring and lysine a side-chain amine. Counting the free amino and carboxylic acid ends, the copper-free peptide carries a calculated net charge of about plus one at pH 7.

The sequence contains no cysteine, methionine or tryptophan, the residues most prone to air oxidation in peptides, and no asparagine or glutamine.³

One name, several records

PubChem holds more than one record under the name GHK-Cu. The records differ in how many peptides are bound to each copper ion (one or two) and in protonation state, which changes the formula, charge and molecular weight. Examples are a 1:1 record at 400.90 g/mol (CID 139035031)¹ and a 2:1 record at 744.3 g/mol (CID 133697840).⁵ Identity for each lot is checked on its Certificate of Analysis.⁴

Molecular profile

Name: GHK-Cu
Also catalogued as: Gly-His-Lys-Cu(II)
Class: Copper(II) complex of a synthetic tripeptide
Peptide sequence: Gly-His-Lys
Formula, reference record: C₁₄H₂₁CuN₆O₄⁻
Molecular weight: 400.90 g/mol
Monoisotopic mass: 400.09 Da
PubChem CID, reference record: 139035031
InChIKey, reference record: LREZPQNYQZAPJC-ACMTZBLWSA-L
Peptide alone: C₁₄H₂₄N₆O₄, 340.38 g/mol
CAS, reference record: Not listed on record
CAS, peptide alone: 49557-75-7
PubChem CID, peptide: 73587
InChIKey, peptide: MVORZMQFXBLMHM-QWRGUYRKSA-N
Physical form: Blue lyophilized powder
Purity: ≥99% by HPLC, per lot
Documentation: Lot-specific Certificate of Analysis

Reference record: PubChem CID 139035031.¹ Peptide record: PubChem CID 73587.² Form and purity: Oasis Labs material specification, confirmed per lot on the COA.⁴ Technical data are provided for guidance. For lot-specific data, refer to the Certificate of Analysis.

Handling

GHK-Cu is a dry solid as received in the laboratory. General handling guidance for lyophilized peptides applies.³

Allow the sealed container to reach room temperature before opening, so moisture does not condense on the solid.³
Keep the solid dry and away from bright light. Moisture lowers long-term stability.³
Avoid repeated freezing and thawing.³

Storage and stability

State	Temperature	Notes
Dry, sealed	-20 °C, or preferably -80 °C³	Keep dry and away from bright light. Moisture lowers long-term stability.³
Freezing and thawing	Avoid repeated freezing and thawing	Applies to the dry solid.³

How each lot is tested

Each lot is tested by an independent third-party laboratory.⁴ The GHK-Cu certificate page names the testing laboratories and lists each lot's purity, net content and test date. Three measurements are reported.

Identity

Mass spectrometry

Checks that the measured molecular mass is consistent with the expected identity of the material.

Mass does not confirm the order of residues or how the copper ion is bound.

Purity

High-performance liquid chromatography (HPLC)

Separates the material from synthesis-related impurities. Purity is reported as the main peak's share of the total detected signal.

Reported per lot. The Oasis Labs specification is 99% or greater.

Quantity

Net content

Measures the mass of material actually present in the sample tested.

Reported per lot on the Certificate of Analysis.

Technical notes

What does the Certificate of Analysis confirm?

Identity by mass spectrometry, purity by HPLC, and the net content of the sample. Mass spectrometry confirms molecular mass, not the order of residues.

What is the difference between GHK and GHK-Cu?

GHK is the copper-free tripeptide, C₁₄H₂₄N₆O₄ at 340.38 g/mol. GHK-Cu is that peptide bound to a copper(II) ion. They are different materials with different identifiers.

Why do PubChem records for GHK-Cu show different formulas?

The name is used for more than one form: complexes with one or two peptides per copper ion, in different protonation states. Each form has its own record, formula and molecular weight. The figures on this page follow the 1:1 reference record cited in the Oasis Labs specification; the salt form of the solid is not specified.

Why is the material freeze-dried?

Peptides are most stable as dry solids. Moisture reduces long-term stability, so the material is lyophilized and kept sealed until use in the laboratory.

GHK-Cu lot certificates

Each listed GHK-Cu lot has its own certificate covering identity, purity and net content.

View GHK-Cu certificates Testing methodology

Catalogue entry: GHK-Cu

References

National Center for Biotechnology Information. PubChem Compound Summary for CID 139035031 (GHK-Cu, 1:1 copper complex). pubchem.ncbi.nlm.nih.gov/compound/139035031. Accessed 16 October 2026.
National Center for Biotechnology Information. PubChem Compound Summary for CID 73587 (glycyl-L-histidyl-L-lysine). pubchem.ncbi.nlm.nih.gov/compound/73587. Accessed 16 October 2026.
MilliporeSigma (Merck KGaA). Handling and storage guidelines for peptides and proteins (technical article). merckmillipore.com. Accessed 14 October 2026.
Oasis Labs. GHK-Cu Certificate of Analysis page, lot data and testing laboratories, myoasislabs.com/coa/ghk-cu/, and testing methodology, myoasislabs.com/coa-process/.
National Center for Biotechnology Information. PubChem Compound Summary for CID 133697840 (GHK-Cu, 2:1 record). pubchem.ncbi.nlm.nih.gov/compound/133697840. Accessed 16 October 2026.

References document the chemical identity, analytical characterisation and handling of this material. Composition and the calculated net charge are derived from the peptide sequence.