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Paperwork guide

How to Read a Peptide COA

A certificate of analysis (COA) is the paperwork that tells you what is actually in a vial. This guide walks through each line so you can read any report with confidence.

1. Sample and lot identification

The top of the report names the compound, the sample or lot code, and the date it was analysed. The lot code should match the label on the vial you receive. If a report has no lot code, you can't tie it to your vial.

2. Content (mg per vial)

Content is the measured amount of peptide in the vial, for example 10.4 mg for a 10 mg vial. A result at or slightly above the label claim is normal. A result well below it means the vial is under-filled.

3. HPLC purity

High-performance liquid chromatography separates the target peptide from impurities. Purity is shown as a percentage of the total signal; research-grade material is typically reported at 98% or higher.

4. Endotoxin

Some reports include an endotoxin result, usually in EU/mg. Lower is better. Not every report includes it, so check whether it's listed.

5. Verify the report yourself

Reputable labs print a verification key or QR code on each report. Enter the key on the lab's verification page and confirm the compound, lot and results match what you were shown.

  • Open the lab's verify page (for Janoshik reports: janoshik.com/verify)
  • Enter the key printed on the report
  • Check the compound, lot code and numbers match

Warning signs

Blurred or cropped verification keys, missing lot codes, edited numbers, or one report reused across many products are all reasons to be cautious. We publish every report in full and unedited on our lab results page.

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