GHK-Cu vs KPV

A neutral reference comparing sequence, molecular class and areas of published research. No claims about effects.

GHK-Cu and KPV are both very short peptides made of just three amino acids, and both are often grouped together in discussions of research peptides. Despite the similar size, they are different in composition, origin and in the way they show up on analytical reports. This page is a neutral reference comparison for qualified researchers, covering sequence, molecular class, regulatory context and areas of published research. It makes no claims about effects, safety or use.

1. At a glance

	GHK-Cu	KPV
Full name	Copper(II) complex of glycyl-L-histidyl-L-lysine	L-lysyl-L-prolyl-L-valine
Sequence	Gly–His–Lys	Lys–Pro–Val
Molecular class	Tripeptide, supplied as a copper-peptide coordination complex	Tripeptide, a fragment of a larger hormone peptide
Length	3 residues	3 residues
Occurrence	Occurs naturally; the peptide was first isolated from human blood plasma	Corresponds to the C-terminal residues (11–13) of alpha-MSH
Contains a metal	Yes: copper(II)	No
Approximate molecular weight	About 0.40 kDa for the copper complex (about 0.34 kDa for the peptide alone)	About 0.34 kDa
CAS number	89030-95-5 (copper complex)	67727-97-3
Appearance as a powder	Typically blue to violet, from the copper	Typically white to off-white
Regulatory status (see Section 2)	Not approved as a medicine; appears as a cosmetic ingredient in some products	Not approved as a medicine
Trinity Research format	Lyophilised research material, sealed vial	Lyophilised research material, sealed vial

Weights and identifiers are shown for orientation and should be checked against the Certificate of Analysis for your lot. The figures that apply to your material are the ones on that report.

2. Regulatory context

GHK-Cu has not been approved as a medicine. A copper tripeptide with the cosmetic-ingredient name “copper tripeptide-1” is used in some topical cosmetic products. Material supplied by Trinity Research is a laboratory research material. It is not a cosmetic product, is not made or tested as one, and is not for human or veterinary use.
KPV has not been approved as a medicine for any use.

Nothing on this page should be read as encouraging the human use of any research material. Anyone with a medical question should speak to a licensed healthcare professional.

3. Sequence and molecular class

Both peptides have three residues, and each contains the basic amino acid lysine. Beyond that, their compositions are different. GHK contains glycine, histidine and lysine. The histidine and the neighbouring residues are the parts of the molecule that bind a copper(II) ion, which is why the peptide is described in the literature as a copper-binding tripeptide. The copper is an integral part of the complex that GHK-Cu refers to.

KPV contains lysine, proline and valine. It has no metal, and it is a fragment cut from a longer peptide hormone, alpha-melanocyte-stimulating hormone (alpha-MSH), rather than a free-standing sequence.

4. Where each comes from

The GHK sequence was first identified in human blood plasma in the early 1970s, and is described in the literature as occurring naturally in body fluids. The material supplied for research is made by chemical synthesis. KPV is likewise produced by chemical synthesis. Its sequence is defined by its position at the C-terminal end of alpha-MSH, and a fragment of that kind is typically studied to see which parts of a larger molecule matter for a particular activity.

5. Areas of published research

	GHK-Cu	KPV
Areas described in the literature	Copper-peptide biology; extracellular-matrix and tissue-remodelling research in cell and animal models; skin-related models	Inflammation-signalling research in cell and animal models, including intestinal and skin-related models

The table lists the areas in which the published literature has studied each molecule. It is a classification and not a comparison of activity. It does not describe any biological or clinical outcome, and it should not be read as a statement about any particular use. Readers interested in the underlying biology should consult the primary literature directly.

6. How they differ on a Certificate of Analysis

The masses are close. The two peptides are only about two mass units apart (roughly 340.4 for GHK, and 342.4 for KPV). With a suitable instrument the difference is clear, but this is a pair where an identity result really does matter, and where the compound name and observed mass on the report should be read carefully.
Copper changes the picture. In GHK-Cu, the copper is part of the complex. Mass spectra of a copper complex show the characteristic pattern of the two natural copper isotopes, and a report may distinguish the free peptide from the complexed form. Copper content is measured by a separate test, and not every report includes it.
Small peptides elute early. Very small, polar peptides such as these can leave an HPLC column early, close to the solvent front. The method matters, and it is worth checking that the main peak is well separated from the front.
Neither contains an aromatic side chain that absorbs strongly at 280 nm. Detection is therefore usually done at short wavelengths, around 214 nm.
Only what is listed was tested. Do not assume other tests were run.

For the background, see our guides on HPLC and mass spectrometry and on reading a Certificate of Analysis, and for the link between a vial and its report see lot numbers and traceability.

7. What this comparison does not cover

This page does not compare effects, outcomes, safety or tolerability, and gives no information on doses, preparation or administration. Trinity Research does not provide dosing, reconstitution, administration, clinical, medical, veterinary or treatment guidance of any kind. Values are given for identification and reference and may be updated as the literature and regulatory position change.