Why is lysine K and not L?

L was already assigned to leucine. K was chosen as the nearest available letter, a historical accident of the coding system rather than a mnemonic.

Is GHK the same as copper tripeptide-1?

Copper tripeptide-1 is the INCI cosmetic ingredient name for the copper complex. Same substance, different naming system.

Does GHK without -Cu mean no copper?

Strictly yes, and the two differ by 62.54 Da. In practice the terms are used loosely, so check the certificate.

What Does GHK Stand For?

The short answer

GHK is the single-letter amino acid code for the peptide's three residues: G for glycine, H for histidine, K for lysine. The -Cu suffix in GHK-Cu denotes a bound copper(II) ion, distinguishing the complex from the free peptide.

Key facts

G: Glycine
H: Histidine
K: Lysine
Full name: Glycyl-L-histidyl-L-lysine
-Cu suffix: Bound copper(II)
Other names: Prezatide; copper tripeptide-1 (INCI)

Why K for lysine

The single-letter code assigns L to leucine, which was claimed first, so lysine took K as the nearest available letter. The system was designed in the 1960s to compress sequence data, and several of its assignments are historical accidents of that kind rather than mnemonics. Knowing this saves the confusion of looking for a letter that matches the name.

Reading the full chemical name

Glycyl-L-histidyl-L-lysine spells the same thing out formally. The -yl endings indicate residues joined by peptide bonds, and the L prefixes specify stereochemistry (the naturally occurring form of each amino acid). Only lysine retains its full name because it is the C-terminal residue with a free carboxyl group.

Research material referenced

GHK-Cu 100mg, third-party HPLC tested

Buy GHK-Cu · £24.99

What the -Cu means

It denotes copper(II) bound to the peptide. This is a real chemical distinction rather than a formatting convention: GHK is 340.38 Da and GHK-Cu is 402.92 Da, and they have different CAS numbers. Writing GHK when you mean the complex is imprecise in a way that matters for any calculation.

The other names in circulation

Prezatide is an assigned generic name. Copper tripeptide-1 is the INCI name used for cosmetic ingredient labelling. Liver cell growth factor appears in early literature, reflecting the assay GHK was discovered in. All refer to the same peptide, and searching under the alternatives surfaces records the abbreviation misses.

Frequently asked questions

Why is lysine K and not L?: L was already assigned to leucine. K was chosen as the nearest available letter, a historical accident of the coding system rather than a mnemonic.
Is GHK the same as copper tripeptide-1?: Copper tripeptide-1 is the INCI cosmetic ingredient name for the copper complex. Same substance, different naming system.
Does GHK without -Cu mean no copper?: Strictly yes, and the two differ by 62.54 Da. In practice the terms are used loosely, so check the certificate.

Extended research context

The GHK-Cu (Copper Peptide) deep dive

Deep dive: why the copper ion matters

The GHK tripeptide (Gly-His-Lys) coordinates a Cu²⁺ ion through the imidazole nitrogen of histidine, the terminal α-amino group of glycine, and a deprotonated peptide-bond nitrogen. This near-square-planar geometry is what gives the complex its characteristic deep-blue colour and its redox-modulating chemistry. Uncomplexed GHK is a different molecule pharmacologically. Nearly every peer-reviewed study attributes activity to the copper-bound form, which is why suppliers ship the pre-complexed GHK-Cu rather than plain GHK.

GHK-Cu in the transcriptomic literature

The most-cited modern papers on GHK-Cu come from the Pickart & Margolina group and independent transcriptomic re-analyses. GHK-Cu has been reported to modulate expression of >4,000 human genes at nanomolar concentrations in Broad Institute Connectivity Map re-analyses, including genes involved in DNA repair, antioxidant defence, and ECM remodelling. This gene-signature-level activity is the reason GHK-Cu appears in so many research reviews outside of dermatology.

Analytical fingerprinting of GHK-Cu

On reverse-phase HPLC, GHK-Cu elutes as a well-defined peak; free GHK and copper-free peptide impurities are distinguishable. UV-Vis at ~520 nm confirms the copper d-d transition band. Reputable suppliers publish both HPLC (≥98% area) and mass-spec identity (~340 Da complex, 340.4 free peptide) on the batch CoA.

Research applications

▸In vitro fibroblast and keratinocyte gene-expression studies
▸ECM turnover assays (collagen, elastin, decorin, MMP profiling)
▸Wound-healing scratch assays in cell culture models
▸Antioxidant-mechanism studies (copper redox modulation)
▸Formulation R&D: cosmetic and topical carrier compatibility research

Handling checklist

✓Store lyophilised vial at 2–8 °C, protected from light
✓Reconstitute with bacteriostatic or sterile water; expect a blue-tinted solution
✓Avoid contact with reducing agents (ascorbic acid destabilises Cu²⁺)
✓Aliquot reconstituted solution for freeze/thaw minimisation
✓Verify blue colour and CoA HPLC ≥98% before use

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Buying GHK without copper

Fix: Confirm the CoA reads GHK-Cu (copper-bound); free GHK is a different pharmacology.

✗ Mixing with vitamin C in solution

Fix: Ascorbate reduces Cu²⁺ to Cu⁺ and destabilises the complex, keep them separate.

✗ Exposing to sunlight

Fix: Store in amber vial or foil-wrapped container at 2–8 °C.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

UKP

Written and reviewed by

The UK Peptides Editorial Team · Research library, UK Peptides

The editorial team is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate. Corrections are made in place and the review date updated.

How we write and check this content Report a factual error in this article

More GHK-Cu (Copper Peptide) articles

Popular across the research hub

One flagship guide from every other research category.

← Back to Forum