A certificate of analysis, or COA, is a lab report for one specific lot of a material. For a peptide it says what the lot is, how pure it is, and what else is in it. Anyone selling a peptide product should be able to show you one.
Here’s what you’ll usually find on a COA for a copper peptide, top to bottom.
The header
- Product name, for example GHK-Cu or copper tripeptide-1.
- Lot or batch number. This is the important one. A COA describes one lot only. If the number on the certificate doesn’t tie back to the product in your hand, the certificate tells you nothing about it.
- Dates. When the lot was made and when it was tested.
- Who tested it. The name of the lab or manufacturer, and ideally a signature or approval.
Appearance
A short description of what the material looks like. For GHK-Cu and AHK-Cu this should say blue powder. It’s a basic check, but a real one.
Identity
This confirms the material is the molecule it claims to be. The usual method is mass spectrometry, listed as MS. The lab measures the molecular weight and compares it with the expected value. For the GHK peptide the expected weight is about 340.
Purity
The headline number, measured by HPLC, a method that separates a sample into its components and measures how much of each is present. Purity is given as a percentage, and for a cosmetic-grade peptide you’d hope to see 98% or higher.
Check that a method is named. “Purity: 99%” with no method next to it is a claim, not a result.
Copper content
For a copper peptide the certificate should report how much copper is present. In theory a complex with one copper for every GHK is about 16% copper by weight. Real lots come in under that because the powder also holds some water and other ions, so suppliers quote a range.
Water content
Peptide powders absorb moisture from the air. Water content, often measured by a method called Karl Fischer, tells you how much of the powder’s weight is water. A few percent is normal.
Contaminants
Better certificates also report:
- Heavy metals such as lead, arsenic and mercury, which should be at trace levels or not detected.
- Microbial counts, showing the lot isn’t carrying bacteria, yeast or mould above set limits.
Signs a COA can’t be trusted
- No lot number, or a lot number that doesn’t match anything on the product
- No date and no lab name
- Results with no test method
- The same PDF handed out for every order, month after month
- Numbers that are suspiciously round, like exactly 99.00% on every line
What a COA doesn’t tell you
A peptide COA covers the raw powder. It isn’t a test of the finished cream or serum, and it doesn’t prove how much powder went into the product. That part depends on the maker being straight with you about the strength.
That’s why Sine Cera prints the percentage and milligrams on the label and lists each batch on the batch COA page, with the peptide lot that went into it.