GHK-Cu Testing and Verification
Independently verify what is actually in your GHK-Cu (copper tripeptide-1) vial. KMD Analytical tests mail-in samples by RP-HPLC-UV against a certified reference standard and reports identity, chromatographic purity, and net-peptide content.
What GHK-Cu is
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine (Gly-His-Lys), a naturally occurring peptide sequence. In the complexed form a copper(II) ion is coordinated by the peptide, which gives the material its characteristic blue color and distinguishes it from the uncomplexed free peptide (GHK). It carries the cosmetic-ingredient name copper tripeptide-1 (INCI) and is typically supplied as a lyophilized powder for reconstitution. Because it is both a peptide and a metal complex, its identity depends on both the correct amino-acid sequence and an intact copper coordination.
Why get your GHK-Cu independently tested
- Free peptide vs. copper complex confusion: plain GHK (a white powder) and GHK-Cu (the blue copper complex) are easily substituted or mislabeled. Matching your sample's retention time and UV spectrum to a certified GHK-Cu reference standard confirms which form you actually received.
- Complex integrity: incomplete or degraded copper coordination changes how the material behaves chromatographically. Because the copper complex and the free peptide elute differently and present different UV spectra, spectral matching flags material that is not the intact complex it claims to be.
- Net-peptide content: lyophilized vials frequently contain bulking agents such as mannitol, or are simply underfilled. The net-peptide assay quantifies how many milligrams of peptide are actually in the vial versus the label claim.
- Chromatographic purity: unregulated-market supply can carry synthesis byproducts, truncated or deletion sequences, and degradation products. Area-percent purity from HPLC shows how much of the sample is the main peak versus everything else.
What we measure on GHK-Cu
Every certificate reports three results from a single RP-HPLC-UV run with UV/diode-array detection at 214 nm. Identity is confirmed by matching your sample's retention time and UV spectrum to a certified GHK-Cu reference standard. Chromatographic purity is reported as area percent of the main peak, and the net-peptide assay reports the milligrams of peptide per vial measured against the same standard.
Every result is issued as a certificate of analysis you — or anyone you forward it to — can verify cryptographically. Reporting identity, purity, and milligram content is the point: a vial can be pure and still underfilled, so we report all three. More on purity vs. net-peptide content and how to read a peptide COA.
Our scope — stated plainly
Testing is by RP-HPLC-UV against a certified reference standard. The method verifies peptide identity, purity, and content; it does not quantify elemental copper or copper-to-peptide stoichiometry (which requires methods such as ICP), and it does not include mass-spec, sterility, endotoxin, heavy-metals, or residual-solvent testing. Where a suitable certified GHK-Cu reference standard is not already on hand, one may need to be sourced first, which can add lead time.
KMD is an independent RP-HPLC-UV lab. We do not run LC-MS / mass-spec, sterility, endotoxin, or heavy-metal testing. If your job needs a capability we don't have, we'll say so.
GHK-Cu testing — FAQ
Can you tell whether my sample is actually the copper complex (GHK-Cu) and not plain GHK?
Yes. Identity is established by retention-time and UV-spectral match to a certified GHK-Cu reference standard. The copper complex and the uncomplexed free peptide elute differently and show different UV spectra, so a sample that is actually plain GHK will not match a GHK-Cu standard.
Do you measure the copper content or the copper-to-peptide ratio?
No. Our RP-HPLC-UV method confirms identity, chromatographic purity, and net-peptide content against a reference standard. Quantifying elemental copper or copper-to-peptide stoichiometry requires other techniques, such as ICP, that are outside our testing scope.
What do you report on the certificate?
Exactly three results: identity (retention-time and UV-spectral match to a certified reference standard), chromatographic purity (area percent), and net-peptide assay (milligrams of peptide per vial). It is a mail-in analysis of the sample you send.
Other peptides we test
Retatrutide · Cagrilintide · Tesamorelin · BPC-157 · see the full panel.