Copper Tripeptide-1 (GHK-Cu) bulk powder for formulators

Copper Tripeptide-1 is the INCI name for the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine, better known in sourcing conversations as GHK-Cu. It is the most requested peptide raw material on this site: serum, ampoule and scalp-tonic formulators ask for it by name, and they usually ask the same four things first. What is the CAS number on the paperwork. Is the material the copper complex or the free peptide. What purity does the lot COA actually show. Can they start with a few grams rather than a production quantity.

This page answers those questions with supplier facts rather than adjectives. The powder is manufactured by Pepti, Guangzhou and supplied as bulk powder from 5 g, shipped cold-chain, with a lot certificate of analysis showing HPLC purity and mass-spectrometry identity, and a safety data sheet on request. Two public batch records for GHK-Cu are already published in the Pepti COA library and are linked below so you can read the reported purity before you ask for a quote.

Identity: which GHK-Cu you are buying

Three different identities travel under the name "GHK-Cu", and a formulator's paperwork should match the one that is actually in the jar.

• The copper complex, CAS 89030-95-5. One tripeptide bound to one copper(II) ion. This is the material Pepti supplies and the number printed on its batch records. PubChem lists it under CID 71587328 (title "Prezatide copper"), with a molecular formula of C14H23CuN6O4 and a weight of about 402.9 g/mol.
• The copper-free tripeptide GHK, CAS 49557-75-7. PubChem CID 73587, C14H24N6O4, about 340.4 g/mol. Several raw-material catalogues print this CAS for their GHK-Cu because the INCI entry historically referenced it. If your supplier prints 49557-75-7, ask whether copper is complexed in the powder or whether you are expected to add a copper salt yourself.
• Bis(Tripeptide-1) Copper Acetate, CAS 130120-57-9. A different INCI entry with two peptides per copper and an acetate counter-ion. It is not the same ingredient and should not be labelled as Copper Tripeptide-1.

Because the two first numbers describe the same tripeptide with and without copper, the mass-spectrometry line on the COA is the quickest way to tell them apart. A copper complex shows a protonated ion near 402.9 m/z; the free peptide shows about 341.4 m/z. The Pepti records linked below report the complex.

Appearance, solubility and handling

Copper Tripeptide-1 powder is blue. The exact shade, from a pale sky blue to a deeper violet-blue, shifts with water content and particle size and is not by itself a quality indicator; the COA purity figure is. A powder that has turned green-grey or brown has usually been exposed to a reducing environment or has absorbed moisture and should be checked before use.

The peptide dissolves readily in water and in water-glycerin mixtures, giving a clear blue solution. It is far less soluble in ethanol and effectively insoluble in oils and silicones, which is why it is normally added to the aqueous phase at the end of processing, below 40 °C, rather than to a hot oil phase. The powder is hygroscopic. Weigh it quickly, close the container at once, and let a cold container reach room temperature before opening so that condensation does not form on the powder.

For long-term storage Pepti recommends −20 °C with the container sealed and protected from light; 2–8 °C is adequate for working stock that will be used within the formulator's own confirmed window. These are the same conditions printed on the lot COA, and the lot record also states a retest date.

What the published literature reports

GHK was first isolated from human plasma by Loren Pickart in the early 1970s, and the copper complex has since been the subject of a large body of in-vitro, animal and small cosmetic studies. Pickart and Margolina's 2018 review in the International Journal of Molecular Sciences summarises reports of effects on collagen and glycosaminoglycan synthesis, on wound-healing models and on gene expression, and discusses cosmetic use in creams and serums (Pickart L, Margolina A. Int J Mol Sci, 2018).

An earlier review by the same author in the Journal of Biomaterials Science, Polymer Edition covers the tissue-remodelling literature and the copper-binding chemistry of the peptide (Pickart L. J Biomater Sci Polym Ed, 2008).

Those reviews are the background a formulator should read. They are not product claims, and nothing on this page should be read as a promise about what a finished product containing this raw material will do. Claims for a finished cosmetic are made and substantiated by the brand in each market, not by the raw-material supplier.

Formulation notes for the bench

The points below are chemistry, not efficacy. They are the issues that come up most often when a formulator moves from a bench sample to a stability batch.

• Chelators strip the copper. EDTA and its salts bind copper(II) more strongly than the tripeptide does. A formula with a chelator in the water phase will gradually pull copper off the peptide, and the blue colour fades as it does. Either leave the chelator out, use a weaker one, or accept that the finished product contains Tripeptide-1 plus a copper-EDTA species rather than the complex you bought.
• Reducing agents change the oxidation state. Ascorbic acid and some thiols reduce Cu(II) to Cu(I). Colour change is the first sign. Keep strong reducers in a separate product or a separate phase.
• pH window. The complex is normally handled between pH 5 and 7.5. Strongly acidic bases protonate the histidine and loosen copper binding; strongly alkaline bases precipitate copper hydroxide.
• Heat and light. Add in the cool-down phase and protect the finished product from light. Opaque or amber packaging is usual.
• Colour in the finished product. At typical use levels the blue is visible in clear serums. Brands either embrace it or mask it with an opaque emulsion; both are routine.
• Preservation. Peptide solutions are nutrient-rich. Water-phase preservation should be confirmed by challenge test in the buyer's own base, not assumed from the supplier's data.

Use level is set by the formulator from their own stability and tolerance work. Pepti supplies identity and purity documentation; it does not publish a recommended use level for finished products.

Specification and documents for this material

Each lot ships with a certificate of analysis that reports reverse-phase HPLC purity (area %), mass-spectrometry identity against the expected molecular weight, appearance, and the storage and retest statements. Water content and counter-ion are reported where the buyer's specification calls for them. A safety data sheet in the standard 16-section format is available for the raw material, and the manufacturer address on both documents is the Pepti site in Guangzhou.

Public batch records for GHK-Cu are listed in the table below with their reported purity. They are vial-format records from the manufacturer's library; the bulk-powder lot you receive carries its own COA with its own lot number, and that document, not the public record, is the one to file with your batch paperwork.

Public batch records for GHK-Cu

Vial-format records published by the manufacturer. Reported HPLC purity is per lot; your bulk-powder lot carries its own COA.

Record	Specification	HPLC purity	Record page
PEP260704-CU50	50 mg vial	99.3%	Open record PEP260704-CU50 on peptioem.com
PEP260705-CU100	100 mg vial	99.6%	Open record PEP260705-CU100 on peptioem.com