GHK-Cu Peptide

Overview

What is GHK-Cu peptide?

GHK-Cu is glycyl-L-histidyl-L-lysine bound to copper(II). Its names, CAS and UNII numbers, where it was found, and why public records disagree.

By the GHK-Cu Peptide editorial team · Last reviewed · Editorial review: pending

Short answer

GHK-Cu peptide is glycyl-L-histidyl-L-lysine bound to a copper(II) ion. GHK was identified as a tripeptide in human serum in 1977 [Schlesinger 1977], and it binds copper(II) with very high affinity [Trapaidze 2012]. Its registered names are prezatide (the peptide) and prezatide copper (the complex) [FDA GSRS], and its cosmetic ingredient name is copper tripeptide-1 [PubChem]. It is not an approved drug in the United States [openFDA].

Identity at a glance

GHK and GHK-Cu identifiers
IdentifierGHK (copper-free)GHK-Cu (1:1 complex)
SequenceGly-His-LysGly-His-Lys · Cu(II)
Nonproprietary namePrezatide (UNII 39TG2H631E) [FDA GSRS]Prezatide copper (UNII 6BJQ43T1I9) [FDA GSRS]
CAS number49557-75-7 [PubChem]89030-95-5 [PubChem]
Cosmetic (INCI) nameTripeptide-1Copper tripeptide-1
PubChem CID7358771587328 (and others, see below)
FormulaC14H24N6O4C14H23CuN6O4⁺ (as recorded)
Molecular weight340.38 g/mol402.92 g/mol (as recorded)

Where GHK came from

GHK was identified in 1977 as a growth-modulating tripeptide in human serum [Schlesinger 1977]. By 1980 the same group reported that, in plasma, it was associated with copper and iron, and that in vitro it associated with several transition-metal ions but not with calcium, potassium or sodium [Pickart 1980]. Equilibrium measurements in 1981 showed that GHK could compete with albumin for copper(II) at pH 7.5 [Lau 1981], and in 2021 two ternary complexes between copper-bound GHK and albumin were characterised [Bossak-Ahmad 2021]. A review reports that serum GHK averages about 200 ng/mL at age 20 and about 80 ng/mL by age 60, figures it cites from earlier work [Dou 2020].

How the copper is held

In solution at neutral pH, copper(II) is bound by three nitrogen atoms of the peptide (the glycine amine, the deprotonated amide nitrogen of the Gly–His bond and a histidine imidazole nitrogen) with a labile oxygen in the fourth position; in the crystal the complex forms a dimer [Hureau 2011]. The interactive explorer and a coordination diagram are on the molecular structure page.

What GHK-Cu is not

  • Not an approved drug. No approved application or listed drug product names prezatide or copper tripeptide [openFDA].
  • Not cleared for injectable compounding. FDA lists GHK-Cu for injectable routes in Category 2 of its compounding safety-risk list [FDA 2026].
  • Not interchangeable with GHK. Copper changes the mass, charge and chemistry; see GHK vs GHK-Cu.

Frequently asked questions

What does GHK stand for?

GHK is the one-letter code for the three amino acids in the peptide: glycine (G), histidine (H) and lysine (K), joined in that order.

Is GHK-Cu the same as copper tripeptide-1?

Copper tripeptide-1 is the cosmetic ingredient (INCI) name attached to the PubChem record for prezatide copper, the 1:1 GHK–copper complex. Product labels using either name do not state which copper-to-peptide ratio or salt form they contain.

Is GHK-Cu natural?

GHK was first isolated from human serum, and a GHK sequence occurs in type I collagen. GHK-Cu sold today is made by chemical synthesis.

What is the CAS number of GHK-Cu?

PubChem lists CAS 89030-95-5 for prezatide copper (the 1:1 complex) and CAS 49557-75-7 for copper-free GHK. A 2:1 bis-complex is listed separately under CAS 130120-56-8.

References

  1. Schlesinger DH, Pickart L, Thaler MM (1977). Growth-modulating serum tripeptide is glycyl-histidyl-lysine. Experientia. PubMed 858356 · doi:10.1007/BF02002806[Chemistry, grade D]
  2. Pickart L, Thaler MM (1980). Growth-modulating tripeptide (glycylhistidyllysine): association with copper and iron in plasma, and stimulation of adhesiveness and growth of hepatoma cells in culture by tripeptide-metal ion complexes. J Cell Physiol. PubMed 6246126 · doi:10.1002/jcp.1041020205[In vitro, grade D]
  3. Lau SJ, Sarkar B (1981). The interaction of copper(II) and glycyl-L-histidyl-L-lysine, a growth-modulating tripeptide from plasma. Biochem J. PubMed 7340824 · doi:10.1042/bj1990649[Chemistry, grade D]
  4. Hureau C, Eury H, Guillot R et al. (2011). X-ray and solution structures of Cu(II) GHK and Cu(II) DAHK complexes: influence on their redox properties. Chemistry. PubMed 21780203 · doi:10.1002/chem.201100751[Chemistry, grade D]
  5. Trapaidze A, Hureau C, Bal W et al. (2012). Thermodynamic study of Cu2+ binding to the DAHK and GHK peptides by isothermal titration calorimetry (ITC) with the weaker competitor glycine. J Biol Inorg Chem. PubMed 21898044 · doi:10.1007/s00775-011-0824-5[Chemistry, grade D]
  6. Bossak-Ahmad K, Bal W, Frączyk T et al. (2021). Ternary Cu2+ Complexes of Human Serum Albumin and Glycyl-l-histidyl-l-lysine. Inorg Chem. PubMed 34730942 · doi:10.1021/acs.inorgchem.1c03084[Chemistry, grade D]
  7. Dou Y, Lee A, Zhu L et al. (2020). The potential of GHK as an anti-aging peptide. Aging Pathobiol Ther. PubMed 35083444 · doi:10.31491/apt.2020.03.014[Review, grade R]
  8. PubChem, National Library of Medicine. glycyl-L-histidyl-L-lysine (CID 73587). Source[retrieved 2026-11-11]
  9. PubChem, National Library of Medicine. Prezatide copper (CID 71587328). Source[retrieved 2026-11-11]
  10. PubChem, National Library of Medicine. Bisprezatide copper (CID 9831891). Source[retrieved 2026-11-11]
  11. FDA Global Substance Registration System. PREZATIDE, UNII 39TG2H631E. Source[retrieved 2026-11-11]
  12. FDA Global Substance Registration System. PREZATIDE COPPER, UNII 6BJQ43T1I9. Source[retrieved 2026-11-11]
  13. U.S. Food and Drug Administration (2026-04-22). Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Source[retrieved 2026-11-11]
  14. U.S. Food and Drug Administration, openFDA. openFDA Drugs@FDA and NDC directory queries for prezatide, copper tripeptide and GHK. Source[retrieved 2026-11-11]