The Gray-Market Red-Flag Checklist

Ten signs a vendor's certificate of analysis is not evidence. Open any COA, count the flags, and read the score at the bottom. It scores the document in front of you, not the vendor.

1. 1

   No named laboratory, or a logo with no address

   What it looks like. "Tested by our partner lab." A logo in the corner. A certificate with no street address, no phone number and no report number.

   Why it matters. A logo is not a lab. Anyone can lay out a certificate; only a real laboratory can confirm it issued one.

   What to do. Search the lab name. A real lab has an address, a phone number and a report number you can ask it to confirm.

2. 2

   No batch or lot number

   What it looks like. A product name, a purity figure, and nothing tying the document to a production run.

   Why it matters. Without a lot number the certificate cannot be matched to any vial, including yours.

   What to do. Look for a lot number in three places: the certificate, the vial label and the listing. Missing from any one of them is the flag.

3. 3

   The batch number does not match the vial

   What it looks like. The certificate says lot 2311-A. The vial in your hand says 2404-C.

   Why it matters. A real certificate for a different lot describes a different product.

   What to do. Compare before you open the vial. Ask the vendor for the certificate for your lot. "It is all the same" is not an answer.

4. 4

   The same certificate on every product

   What it looks like. Identical report number, date and chromatogram across different peptides, or across months of listings.

   Why it matters. One lot cannot be every lot. A recycled document is the most common way a "tested" vendor has tested nothing recently.

   What to do. Open two listings side by side and compare the report numbers and dates. If they match, neither is evidence for either product.

5. 5

   A test date older than a year, or no date at all

   What it looks like. A 2023 certificate on a listing that is shipping today.

   Why it matters. Old lots sell out. The certificate should describe what ships now, not what shipped once.

   What to do. Check the test date against your order date. More than a year apart, or no date, means ask for a current one.

6. 6

   A purity figure with no method and no chromatogram

   What it looks like. "Purity: 99.8%" on its own. No HPLC named. No trace attached.

   Why it matters. The purity figure is read from the chromatogram. No trace, no evidence. A number without a method is a claim, not a measurement.

   What to do. Look for HPLC (or HPLC-UV) stated next to the purity figure, and a chromatogram image or page you can see.

7. 7

   Purity without identity

   What it looks like. A purity percentage but no mass spectrometry result. No observed mass against an expected mass.

   Why it matters. 99% pure says nothing about which molecule it is. Purity is a ratio of one peak to the rest; identity is what the peak is.

   What to do. Look for MS or LC-MS with an observed mass that matches the expected mass for the peptide on the label.

8. 8

   No net content in milligrams

   What it looks like. The label says 10 mg. Nothing on the certificate measures it. Purity is the only number.

   Why it matters. Purity is a ratio. The milligrams are what you paid for, and a 99% pure vial can still hold 6 mg.

   What to do. Look for net content, quantity or assay in milligrams. That figure is also what a real price per milligram is built on.

9. 9

   No endotoxin or sterility result

   What it looks like. A purity-only certificate with no contamination testing of any kind.

   Why it matters. Purity testing cannot see bacterial contamination. A clean chromatogram and a contaminated vial are not contradictory.

   What to do. Look for a LAL endotoxin result (EU per mg or per vial) and a sterility result.

10. 10

    You cannot see it before you pay

    What it looks like. "COA available on request." "Log in to view." A certificate emailed only after purchase. A cropped screenshot instead of the document.

    Why it matters. A certificate you can only see after paying cannot be checked against the listing, and a cropped image cannot be checked at all.

    What to do. If a vendor will not show the whole document before purchase, treat the listing as untested.

Count the flags

• A certificate worth readingZero to two flags. Now the only question left is whether it describes your vial.
• Partial evidenceThree to five flags. Ask the vendor for what is missing before you buy, not after.
• Not a certificate, a brochureSix or more flags. It is marketing shaped like a lab report.

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New here? Start Here explains how to read a result, and How We Test is the protocol behind every verdict.