How to Read a GHK-Cu Certificate of Analysis: Batch GHK-2607 Line by Line
What each result means for a copper peptide, including why the copper content can be checked with a one-line calculation.
The certificate of analysis for GHK-Cu batch GHK-2607, manufactured on 17 July 2026, is published in our COA library. A copper peptide certificate has one line that ordinary peptide certificates do not: copper content. This walk-through uses the real numbers to show how to read it. The batch code works as molecule plus year and month, so GHK-2607 is GHK-Cu from July 2026.
Identity and the copper calculation
The certificate gives the formula C14H24N6O4 with copper and one acetic acid, which is the copper(II) complex of glycyl-L-histidyl-L-lysine as an acetate salt. You can check the copper content against that formula. The peptide GHK weighs about 340.4, copper about 63.5 and acetic acid about 60.1, so the complex weighs about 464.0, and copper is 63.5 divided by 464.0, or about 13.7% of the total.
The certificate reports a measured copper content of 13.7% against an acceptance range of 8.0% to 16.0%. A result at the calculated value is what a fully complexed 1:1 material would give. A figure much lower would point to free peptide without copper, and a much higher one to excess copper salt.
Appearance: blue to purple
The acceptance criterion for appearance is blue to purple powder, and the batch meets it. The colour comes from the copper(II) ion bound to the peptide, and it is a quick visual check that copper is present. Our article on why GHK-Cu is blue explains the chemistry. A white powder sold as GHK-Cu would be a reason to ask questions.
Purity by HPLC: 99.1% against a limit of at least 97.0%
The certificate labels this line GHK purity by HPLC. HPLC purity is the main peak's share of the total peak area detected, so it describes the peptide's chromatographic purity, while copper content is a separate result. Both need to be in range for the material to be what it says: a pure peptide with the wrong copper content is not GHK-Cu.
Acetic acid and loss on drying
Acetic acid is reported at 12.0% against a limit of 15.0% or less. That fits the formula, in which one acetic acid per complex accounts for about 12.9% of the weight. Loss on drying is 5.2% against a limit of 8.0% or less, which reflects residual moisture in the lyophilized powder. Together with the peptide and copper, these explain why the powder in a vial is not all GHK: it also carries acetate and a little water.
Solubility, microbial limits and endotoxin
The powder meets the requirement of being soluble in water, consistent with the usual practice of reconstituting GHK-Cu in sterile or bacteriostatic water. The total plate count is below 100 cfu/g and moulds and yeasts are below 10 cfu/g. Bacterial endotoxin is reported as below 10 EU/mg, a limit statement rather than a measured value.
Dates, storage and limits of a certificate
The batch was manufactured on 17 July 2026 and tested on 27 July 2026, with a retest date of 16 July 2028. The storage condition is 2 to 8 degrees Celsius, dry and dark. A certificate describes the lot it names, so check that the batch code on the label of your box matches. For an independent check, you can send a vial to Janoshik or another laboratory, and we return the test fee as account credit.
QSC supplies GHK-Cu in 50 mg and 100 mg vials strictly for laboratory research, not for human or veterinary use. For what has been published about the peptide, see our GHK-Cu research evidence article.
