Compound Notes · Jul 28, 2026
BPC-157 vs GHK-Cu: A Peptide and a Metal Complex
These two get grouped together in sourcing discussions, but chemically they are not the same kind of substance at all. One is a peptide. The other is a metal-peptide complex.
The formulas give it away
| BPC-157 | GHK-Cu | |
|---|---|---|
| Molecular formula | C62H98N16O22 | C14H24N6O4Cu |
| Molar mass | 1,419.53 g/mol | 401.94 g/mol |
| CAS | 137525-51-0 | 89030-95-5 |
| Class | 15-residue peptide | tripeptide-copper(II) complex |
That Cu in the GHK-Cu formula is a copper atom, coordinated to the glycyl-histidyl-lysine tripeptide. GHK on its own is a peptide; GHK-Cu is a coordination complex, and the copper is part of the substance rather than a contaminant.
BPC-157 is about 3.5 times heavier and contains no metal.
What that means practically
GHK-Cu has a colour, and the colour is diagnostic. Copper(II) complexes are blue. A correctly made GHK-Cu solution is distinctly blue; the lyophilized solid ranges from blue to blue-violet. If a vial labelled GHK-Cu reconstitutes colourless, something is wrong: either the copper is absent, or the material is not what the label says.
That is a rare gift in this category. Almost every other compound here is a white powder that dissolves to a clear solution, so you cannot tell anything by looking. GHK-Cu you can partially check by eye before any instrument is involved.
The copper also changes what can go wrong. A plain peptide degrades by hydrolysis, oxidation, or aggregation. A copper complex can additionally lose or exchange its metal, and copper can catalyse oxidation of other things in the same solution. So GHK-Cu should not be casually combined with other compounds in one vessel, and chelators will strip it.
Purity means something slightly different here
For BPC-157, HPLC purity is the fraction of material that is the target peptide. For GHK-Cu, a purity figure describes the organic component, and it does not by itself tell you the copper is correctly coordinated or present at the right stoichiometry. Those are separate measurements, and most certificates in this market do not report them.
Worth knowing when comparing two purity numbers that look equivalent. See why purity figures differ between suppliers.
Testing status
Both have analysed lots. BPC-157 lot KP-BPC--2612 reports 99.60% via BT Labs. GHK-Cu lot KP-GHK--2609 reports 99.90% via Krause Analytical. Certificates are on the lab results page.
Related
Supplied as laboratory reagents for research use only.
Compounds covered here
Supplied as a laboratory reagent for research use only. Not for human or veterinary use.
Related reading
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