Glow Peptides · Research Journal

GHK-Cu, GHK Cu and Copper Tripeptide-1: One Compound, Several Names

GHK-Cu, GHK Cu and Copper Tripeptide-1: One Compound, Several Names

Glow Peptides Research Team · 2026-09-02

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

Every one of these names is the same compound

GHK-Cu, GHK Cu, GHK copper and copper tripeptide-1 all name the same copper-bound tripeptide. The peptide portion is glycyl-L-histidyl-L-lysine, and the Cu denotes the copper it holds. PubChem records the chelate under a single identifier with a single molecular formula, so the naming differences are conventions of spelling and labelling rather than differences in the compound itself. That is why a research-grade GHK-Cu peptide carries one set of identity figures on its certificate of analysis no matter which of these spellings the paperwork happens to use.

What GHK-Cu is, compositionally

GHK-Cu is a chelate: a small peptide holding a copper ion. The peptide half of that description is GHK, which Dou et al identify as glycyl-L-histidyl-L-lysine, a naturally occurring peptide found in human serum (PMC8789089). Three amino acid residues, in that order, give the compound its three-letter shorthand. Glycine supplies the G, histidine the H, lysine the K. The same paper records that GHK has a very high affinity for copper and forms the chelate GHK-Cu.

That distinction between the free tripeptide and the copper chelate is the reason this compound accumulated so many names, and it is also the reason the two are catalogued separately. PubChem lists GHK-Cu under CID 71587328 and names glycyl-L-histidyl-L-lysine, CID 73587, as its parent compound. The component compounds recorded for the chelate are glycyl-L-histidyl-L-lysine and copper (PubChem).

The identity figures follow from that composition. PubChem gives the molecular formula as C14H23CuN6O4+, the molecular weight as 402.92 g/mol, and the CAS registry number as 89030-95-5. The formula string carries a charge indicator, which is a reminder that the record describes the copper-bound species rather than the uncharged peptide on its own. Anyone comparing an analytical result against a reference value needs to be clear which of the two records they are comparing against, because the parent tripeptide and the chelate are different entries with different formulae.

For material specification purposes, this is the whole of the compositional description. The Glow Peptides GHK-Cu vial is stated at 50 mg, supplied as a vial of 3 mL, at ≥99.2% (HPLC). A GHK-Cu capsule format is listed separately in the same catalogue. Both are research use only materials, and nothing in this article describes an application, an outcome or a use.

The names you will see, and why they differ

Search demand for this compound is split across a large number of spellings, and none of them denotes a different substance. Four of the variants below are synonyms formally recorded by PubChem against CID 71587328. The rest are typographic habits: whether the copper is joined with a hyphen, a space or nothing at all, and whether it appears as the chemical symbol Cu or as the word copper.

Name — Status — Where the convention comes from
GHK-Cu — Common written form — GHK for the tripeptide, Cu for copper, joined by a hyphen
GHK Cu — Spelling variant — The same name with a space in place of the hyphen
GHKcu — Spelling variant — The same name closed up, common in search queries and forum text
GHK copper — PubChem-recorded synonym — The chemical symbol written out as a word
GHK-copper — Spelling variant — The written-out form carrying the hyphen
Copper tripeptide-1 — PubChem-recorded synonym — Cosmetic ingredient naming convention
Prezatide copper — PubChem-recorded synonym — The record title used by PubChem for CID 71587328
CG-copper peptide — PubChem-recorded synonym — A further synonym carried on the same PubChem record
Copper peptide — Informal category term — A general description rather than a name for a specific compound

Two points are worth stating plainly. First, a hyphen, a space or a closed-up spelling changes nothing about the material. GHK-Cu and GHK Cu are the same compound, and a vial labelled one way is not a different product from a vial labelled the other. Second, copper peptide is the only entry in that table that is not a name for this specific compound. It is a category description, and it can be applied to more than one copper-binding peptide, so a document that only says copper peptide has not actually identified what is in the container.

That is why specification documents work from identifiers rather than from names. CAS 89030-95-5 and PubChem CID 71587328 are unambiguous in a way that no spelling variant can be. When a purchase record, an internal register and a certificate of analysis all carry the same registry number, the naming question resolves itself regardless of which of the nine forms above each document happens to use.

Copper tripeptide-1 is the cosmetic ingredient name

Copper tripeptide-1 is a naming convention drawn from cosmetic ingredient labelling, and PubChem records it as a synonym of the same compound catalogued under CID 71587328. That is the entire scope of the claim being made here. It is a fact about how the compound is named on an ingredient list, not a statement about any application, formulation or effect, and this article makes no such statement.

The reason the name matters to a research supply audience is that it fragments the literature and the search results. A reader who searches for copper tripeptide-1 and a reader who searches for GHK-Cu are looking for the same substance and will land in two largely separate bodies of material, one written in cosmetic ingredient language and one written in peptide chemistry language. Neither set of documents is wrong. They are two naming systems describing one entry in the chemical registries.

The practical consequence is in documentation. If an incoming shipment is described as copper tripeptide-1 and an internal register calls the same material GHK-Cu, a reconciliation step is needed before the two records can be treated as one line item. The fastest way to run that check is the CAS number and the PubChem identifier, both of which are the same across the two naming systems. Where those identifiers are absent, the molecular formula C14H23CuN6O4+ and the recorded molecular weight of 402.92 g/mol serve the same reconciling function.

Naming variance is an administrative problem, not a chemical one. It is solved with identifiers.

How identity is confirmed for a copper-bound peptide

Identity and purity answer two different questions, and a certificate of analysis needs both. Identity asks whether the material in the vial is the compound named on the label. Purity asks how much of the material is that compound. Mass spectrometry is the analytical method that addresses the first question, because it measures mass and mass is a direct consequence of composition.

For a copper-bound peptide, the reference value being compared against is the chelate's, not the free peptide's. PubChem gives the molecular weight of GHK-Cu as 402.92 g/mol against the molecular formula C14H23CuN6O4+, with glycyl-L-histidyl-L-lysine, CID 73587, recorded as the parent compound. Those are two separate registry entries. A result compared against the wrong one is a mis-specified test, not a failed one, which is why the reference identifier belongs in the analytical record alongside the result.

Copper is what makes this distinction load-bearing here rather than a technicality. The copper is part of the recorded formula and part of the recorded mass, so a mass spectrometry result for the chelate should not be expected to match a reference figure calculated for the tripeptide alone. Dou et al describe GHK as having a very high affinity for copper and forming the chelate GHK-Cu, and it is the chelate that the GHK-Cu specification and the GHK-Cu certificate describe.

The certificates state the method rather than leaving it implied. Analysis is performed by HPLC with UV detection coupled with mass spectrometry: purity is determined by HPLC-UV, identity by LC-MS. Reading those as one combined technique is a mistake worth avoiding, because they answer the two different questions set out above. The chromatographic step separates the sample and reports what proportion of the response belongs to the target compound; the mass spectrometric step confirms that the compound the response belongs to is the one named on the label.

Glow Peptides sets out how the two methods sit together, and what each one is and is not evidence of, in its explainer on HPLC and mass spectrometry in purity testing. The broader quality documentation position is set out on the quality page.

How purity is reported for GHK-Cu

Purity for GHK-Cu is reported by HPLC, and Glow Peptides states it as ≥99.2% (HPLC). Three parts of that statement carry information and all three should be read.

The first is the number itself. The second is the inequality: ≥99.2% is a floor, a statement that the lot met or exceeded that threshold, not a claim of an exact value. The third is the method in brackets. A purity figure without a stated method is an incomplete figure, because the number is only meaningful in relation to how it was produced. HPLC in this context is a chromatographic separation, and the percentage describes the proportion of the chromatographic response attributable to the target compound.

GHK-Cu is a single compound, so its purity is stated as a single figure. That is worth naming explicitly, because it differs from how purity is reported for a multi-component blend. Blends in the same catalogue carry the wording ≥99.2% per component (HPLC), where the qualifier does real work: it tells the reader that the threshold applies to each constituent individually rather than to the vial's contents in aggregate. For a single-compound item such as GHK-Cu, the per-component qualifier is unnecessary and correctly absent.

One practical point follows about where the figure should come from. The purity Glow Peptides states for GHK-Cu is ≥99.2% (HPLC), and that is the specification carried on both the product page and the certificate. When a purity value is being entered into an internal register, the figure to record is the one on the certificate for the specific lot received, rather than a value copied from a general product description or from a third-party listing. Lot documentation is the authoritative source, and it is the only source that describes the material actually in hand.

What the certificate reports for a GHK-Cu lot

Every Glow Peptides certificate of analysis page carries the same set of fields: product name, bottle lot, strength, date received, form, purity, released status, COA verified status, a link to the official certificate PDF issued by an independent United States laboratory, and a QR verification code showing the lot number. That fixed structure is what makes two lots directly comparable field by field.

Two GHK-Cu lots are published. The certificate for GHK-Cu lot 260203QL-GH50-01 records a strength of 50 mg, a purity of ≥99.2% (HPLC) and a date received of 2 February 2026. A second GHK-Cu lot, 260406-HP-5H50-05, is published on its own certificate page, carrying the same fields, with its own strength, purity and date received stated there. The figures for one lot are not transferable to the other, which is the point of publishing them separately: the certificate for the lot in hand is the only one that describes the material in hand.

The laboratory behind those documents is named rather than left generic. The official certificates are issued by Freedom Diagnostics in the United States and signed by Stephen Schmidt, Principal Chemist. Each one carries an accession number and a search code, so a lot can be looked up at the laboratory independently of the supplier. For a record-keeping purpose that matters: a verification route that does not run back through the seller is a stronger record than one that does.

Each certificate checked also carries endotoxin testing, performed per USP <85> Bacterial Endotoxins Test and USP <161>, run in duplicate with both replicates passing. Appearance is recorded as well, and for the copper-containing products it is stated as a blue lyophilized powder, against a white lyophilized powder for CJC/Ipamorelin. Appearance is the one certificate field a receiving laboratory can check against the vial without any instrumentation at all, which makes it a useful first step on receipt rather than a decorative detail.

The lot number is the thread that ties a physical vial to a specific document. Glow Peptides states that every vial ships with its own QR code, which pulls up that exact lot's independent laboratory certificate, purity, identity and test date. Each released lot carries one lot number, the rendering shown on its own official certificate, and that number is what the certificate index resolves against. It is an identifier and nothing more: no date, facility or strength should be read out of the characters in it.

Naming variants have no bearing on any of this. Whether the label, the invoice or the internal register says GHK-Cu, GHK Cu or copper tripeptide-1, the lot number and the certificate identify the material. Glow Peptides sets out how to work through each certificate field in its guide to reading a certificate of analysis.

Documenting a GHK-Cu lot on receipt

Handling documentation and product documentation are separate things, and this section only covers the second. The form Glow Peptides records for GHK-Cu, on both the product page and the certificate, is a vial of 3 mL. Form is a certificate field in its own right, which means the physical presentation of the material is part of the documented specification rather than an incidental detail.

This article does not state storage temperatures, handling conditions or preparation steps for GHK-Cu. Those belong on the documentation supplied with the material and in the receiving laboratory's own procedures, not in a general article about naming, and a figure repeated from a third-party page is not a substitute for the documentation that arrived with a specific lot.

What is worth setting out is the record-keeping side, because it is where naming variance causes real problems. A receiving record for a GHK-Cu vial should capture the lot number exactly as printed, the strength, the stated purity and its method, the form, and the certificate reference, alongside whichever name appears on the label. Recording the name alone leaves the record ambiguous, given that the same compound can arrive labelled as GHK-Cu, GHK copper, copper tripeptide-1 or Prezatide copper.

Two further fields are worth capturing at the same time, because both are on the certificate and both are checkable on arrival. The first is appearance, recorded for the copper-containing products as a blue lyophilized powder; a mismatch between the vial and its own certificate is something to raise before the material is entered into the register at all. The second is the laboratory reference, meaning the accession number and search code that Freedom Diagnostics carries on the certificate. Logging that reference alongside the lot number means the record can later be verified at the laboratory rather than only against the supplier's own index, which is worth having in a file that may be read years after the material was received.

Research use only labelling is part of the same documentary picture. The United States Food and Drug Administration publishes guidance for industry and FDA staff titled Distribution of In Vitro Diagnostic Products Labeled for Research Use Only or Investigational Use Only, issued in final form in November 2013. Material supplied for research use is labelled accordingly, and that label travels with the lot record.

Frequently asked questions

Are GHK-Cu and copper tripeptide-1 the same compound?

Yes. GHK-Cu and copper tripeptide-1 name the same compound. PubChem records copper tripeptide-1 as a synonym on the entry for CID 71587328, alongside Prezatide copper, GHK copper and CG-copper peptide. Copper tripeptide-1 is the cosmetic ingredient naming convention for that compound. The molecular formula, the molecular weight of 402.92 g/mol and the CAS number 89030-95-5 are identical whichever of the two names a document uses.

What does the Cu in GHK-Cu stand for?

Cu is the chemical symbol for copper, and in GHK-Cu it denotes the copper the peptide holds. GHK is glycyl-L-histidyl-L-lysine, which Dou et al describe as a naturally occurring peptide found in human serum with a very high affinity for copper, forming the chelate GHK-Cu. PubChem records the chelate under the formula C14H23CuN6O4+, with glycyl-L-histidyl-L-lysine and copper as its component compounds.

Is GHK Cu without the hyphen a different product?

No. GHK Cu, GHK-Cu and GHKcu are spelling variants of one name for one compound. The hyphen, the space and the closed-up form carry no chemical meaning. A vial labelled GHK Cu and a vial labelled GHK-Cu describe the same material, and the way to confirm that in any specific case is the CAS number 89030-95-5, the PubChem identifier CID 71587328, and the lot number printed on the vial.

How is GHK-Cu identity confirmed in a laboratory?

Identity is addressed by mass spectrometry, which measures mass and therefore reflects composition directly. For GHK-Cu the reference figure is the copper chelate's, which PubChem gives as 402.92 g/mol against the formula C14H23CuN6O4+, not the figure for the free tripeptide catalogued separately as CID 73587. Identity and purity are distinct questions, and a complete certificate of analysis reports both rather than treating one as evidence of the other.

What purity is reported for GHK-Cu?

Glow Peptides states GHK-Cu purity as ≥99.2% (HPLC). The inequality means the lot met or exceeded that threshold rather than measured exactly at it, and the bracketed method is part of the figure, since a purity percentage is only interpretable alongside the analytical method that produced it. GHK-Cu is a single compound, so the figure is stated once rather than per component as it is for multi-component blends.

How should a GHK-Cu vial be documented on receipt?

Record the lot number exactly as printed, the strength, the stated purity together with its method, the form, and the certificate reference, alongside whichever name appears on the label. Glow Peptides publishes a certificate page per lot carrying product name, bottle lot, strength, date received, form, purity, released status, verification status and a link to the independent laboratory certificate, and states that each vial ships with a QR code linking to that lot's certificate. The official certificate is issued by Freedom Diagnostics in the United States, signed by Stephen Schmidt, Principal Chemist, and carries an accession number and search code, so the lot can also be looked up at the laboratory. Appearance is a certificate field as well, recorded for the copper-containing products as a blue lyophilized powder, and it is worth checking against the vial on arrival.

Sources

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