How to read a peptide lab report
By BioGenisys Research Team · 5 min read · Updated 2026-10-27
A lab report (also called a certificate of analysis, or COA) is a document from a testing lab about one batch of a compound. It answers three questions: is it the right compound, how clean is it, and how much is in the vial. This guide shows where to find each answer. The numbers below are made-up examples, not results from a real batch.
The short version
- Match the lot number on the report to the lot number on your vial.
- Identity tells you it's the right compound. Purity tells you how clean it is. Net content tells you how much is in the vial.
- A trustworthy report names the lab and the test date, and ideally can be checked on the lab's own website.
1. Start with the lot number
A lot, or batch, is one production run. A report covers one lot only, never a product in general. Every BioGenisys vial label prints its lot number, so check that it matches the lot on the report before you rely on anything else. A report with no lot number, or one used for many lots, tells you nothing about the vial in your hand.
2. Check who tested it and when
The report should name an independent lab (one that doesn't make or sell the compound) and give a test date. Some labs also print a code you can enter on their website to confirm the report is real. If a report offers that, use it.
3. Identity: is it the right compound?
Identity is usually checked with mass spectrometry, often written MS or LC-MS. In simple terms, the instrument weighs the molecules in the sample. Every compound has a known weight, so if the measured weight matches the expected one, it's the right compound. If it doesn't match, the vial holds something else. HPLC and mass spectrometry, explained shows how it works.
4. Purity: how clean is the sample?
Purity is usually measured by HPLC, a test that separates a sample into its ingredients and measures each one. Purity is the share of the sample that is the compound you wanted, as a percentage. A report might say, for example, 99.4%, meaning nearly everything the test detected was the right compound.
Two things to know. Purity is a share, not an amount: it doesn't say how many milligrams are in the vial. And the test only counts what it can detect, so it's one important check, not the whole picture.
5. Net content: how much is in the vial?
Net content is the measured amount of compound in the vial, in milligrams (mg), compared with the amount on the label. It's a separate test from purity. A vial labeled 10mg might test at 9.6 mg, 10.0 mg or 10.8 mg. Purity vs net content explains what readings above and below the label mean.
6. Blends list each compound separately
A blend has two or more compounds in one vial, so its report should list each one on its own line, with its own amount. Some blend reports confirm identity and amount but skip a single purity figure, because one percentage means less for a mix. A good report says so plainly instead of leaving the box empty.
7. Extra tests you might see
Some reports add tests for bacterial toxins (endotoxin), live germs (sterility) or heavy metals such as lead. Endotoxin, sterility and heavy metals explains each one.
8. Warning signs
- No lot number, or a lot that doesn't match your vial.
- No lab name, no test date, or no way to contact the lab.
- The same report used for several products or several batches.
- Results with no test method listed and no way to check them.
- A report that looks edited, or numbers that match the label exactly every single time. Real measurements vary a little.
Where to find ours
BioGenisys lab reports are on the Certificates of Analysis page. For a lot that isn't listed, request its report there and we reply within 2 business days.
For research use only. Not for human or veterinary use.