The molecule we identify.
The assays we run on GHK-Cu.
The failure modes we see most.
- 01Under-stoichiometric copper. The product is sold as 'GHK-Cu' but actual Cu:peptide ratio is 0.5:1 or less. ICP-MS catches this; HPLC alone does not.
- 02Free copper from over-stoichiometric formulations (Cu:peptide > 1.2:1). Free copper accelerates oxidation of other formula ingredients and changes the activity profile.
- 03Net Peptide Content gap. Research-grade GHK-Cu averages 76-86 % NPC. The label-claim concentration is often gross peptide-salt mass rather than active.
- 04Topical formulation degradation. GHK-Cu in cream / serum bases degrades faster than the lyophilized form — stability time points show purity drop within 60-90 days at 25 °C.
- 05Endotoxin contamination on injectable-grade material. The chelation reaction itself can introduce endotoxin if not done in clean conditions.
Transparent panels for GHK-Cu.
HPLC purity + LC-MS identity. Baseline COA — public + accession #.
- HPLC purity %
- LC-MS identity
- Method disclosure
- Public COA + accession #
- 5-7 day turnaround
COA Essentials + ICP-MS Cu:peptide molar ratio + NPC. The cosmetic-active receipt.
- Everything in COA Essentials
- ICP-MS copper quantification
- Cu:peptide molar ratio
- Net Peptide Content
- Conformity Testing +1
- 5-7 day turnaround
Identity + Cu Stoichiometry + USP <51> PET + heavy metals + accelerated stability. The finished-cream COA.
- Everything in Identity + Cu Stoichiometry
- USP <51> PET (28-day challenge)
- Heavy metals ICP-MS
- Accelerated stability (4-week, 40 °C)
- Conformity Testing +1
- 5-7 day turnaround
GHK-Cu testing — the common questions.
Why does the copper stoichiometry matter?+
GHK-Cu is biologically active because of the copper chelate, not just the peptide. The Gly-His-Lys tripeptide on its own (without bound copper) has different activity than the GHK-Cu complex. Vials labeled 'GHK-Cu' with copper stoichiometry of 0.5:1 are functionally half-strength GHK-Cu plus half-strength bare peptide. ICP-MS quantification confirms whether the product is the chelated complex or partially uncomplexed peptide.
Can you test GHK-Cu in finished cosmetic products (cream, serum)?+
Yes. Topical formulation matrices add complication — the cream / serum base interferes with HPLC quantification, requiring sample prep (extraction, dilution) before assay. We've validated methods for typical cosmetic bases (water + emulsifier + glycerin + oil phase). Send the finished product (one container or 30 g equivalent) plus the formulation ingredient list. Pricing matches the standard panel.
What's a reasonable HPLC purity for GHK-Cu?+
92-99 % is typical for research-grade and cosmetic-grade material. Below 90 % usually indicates incomplete peptide synthesis or significant degradation. The chelated copper is removed by the HPLC mobile phase, so what's measured is the peptide purity independent of Cu content — copper stoichiometry is a separate measurement via ICP-MS.
Does GHK-Cu need endotoxin testing?+
Only for injectable-grade material. Topical / cosmetic GHK-Cu does not legally or practically require LAL endotoxin testing. Topical formulations should have USP <51> preservative-efficacy testing instead — that confirms the finished cream survives microbial challenge over 28 days.
Can you test the stability of GHK-Cu in solution?+
Yes. Accelerated stability time-point pulls at Day 7, 14, 28, 56 at 25 °C / 40 °C / 60 % RH. Bundled into the Vendor Full QC panel; available standalone at $99 per pull. We report purity, copper stoichiometry, and color (visual) at each time point.
How does GHK-Cu pricing compare to other testing options?+
Other labs that test GHK-Cu typically only run HPLC purity for the peptide and skip the copper stoichiometry, treating it as an organic-chemistry purity panel. Our Identity + Cu Stoichiometry panel at $399 adds the ICP-MS Cu quantification, which is the more important measurement for product authenticity. Pricing reflects that — single-panel reports the actual GHK-Cu quality rather than 'just the peptide'.
Other copper peptide · cosmetic + repair active testing —
GHK-Cu commonly appears in serums and creams — full cosmetic panel includes PET, MoCRA, heavy metals.
Repair peptide. Different mechanism, similar testing approach (HPLC + MS + NPC).
Full peptide menu — all bundles, panels, and compounds we cover.
Verify the chelate. Sign the COA.
HPLC purity, LC-MS identity, ICP-MS Cu stoichiometry, NPC — Houston bench, public COA, transparent pricing.