Identity · May 30, 2026 · 4 min read
What is GHK-Cu? Names, forms and what to ask a supplier
GHK-Cu is the copper(II) complex of the tripeptide Gly-His-Lys. Its other names, the forms behind its different molecular weights, and the questions that show what a supplier is offering.
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine. The neutral 1:1 complex is C14H22CuN6O4, 401.91 g/mol, and CAS 89030-95-5 identifies the copper complex.
Names you will see
- GHK-Cu, Cu-GHK, GHK copper complex.
- Copper Tripeptide-1.
- Prezatide copper — the name PubChem gives the record under CAS 89030-95-5.
- GHK or Tripeptide-1 on its own means the peptide without copper (CAS 49557-75-7): a different material.
The forms behind different molecular weights
401.91 g/mol is the neutral complex with one GHK per copper. The 2:1 form, two GHK per copper, is 742.3 g/mol. Free GHK is 340.38 g/mol. When two documents disagree on the molecular weight, they usually describe different forms — the molecular weight and CAS guide lists them side by side.
Why it is blue
The copper(II) ion bound in the peptide absorbs light in a broad band near 606 nm, so GHK-Cu powder and its solutions look blue. GHK without copper is white to off-white.
What to ask a supplier
- Which form is it — the 1:1 complex or the 2:1?
- Which CAS is on the COA? 89030-95-5 is the copper complex.
- Can I see the COA of the batch I would receive, with its batch number?
- Which tests are on it: HPLC purity and MS identity at least; copper content and the Cu²⁺ : peptide ratio if you need them.
- How many vials are in a kit, and in which strengths?
Frequently asked questions
- Is GHK-Cu the same as Copper Tripeptide-1?
- Yes. Copper Tripeptide-1 and prezatide copper are other names for the copper(II) complex of Gly-His-Lys, CAS 89030-95-5.
- What is the molecular weight of GHK-Cu?
- 401.91 g/mol for the neutral 1:1 complex; 742.3 g/mol for the 2:1 form; 340.38 g/mol for GHK without copper.
References
- PubChem CID 165429100 — GHK copper complex (C14H22CuN6O4, 401.91) — formula and molecular weight of the neutral 1:1 complex
- PubChem CID 71587328 — prezatide copper (CAS 89030-95-5) — CAS 89030-95-5 belongs to the copper complex; PubChem records it as the singly protonated form, 402.92 g/mol
- PubChem CID 9831891 — bisprezatide copper (C28H46CuN12O8, 742.3) — the 2:1 peptide-to-copper record
- PubChem CID 73587 — glycyl-L-histidyl-L-lysine (C14H24N6O4, 340.38) — GHK identity, formula and molecular weight
- Bossak-Ahmad et al., Int J Mol Sci 2020 — ternary Cu(II) complex with GHK — d–d band of Cu(GHK) at 605–606 nm; aqua copper absorbs near 816 nm
GHK-Cu vials, 10 per kit
Ask for a written quote by the kit and the COA of the batch you would receive.