How to Read a Peptide COA (and Spot a Bad One)

A certificate of analysis (COA) is a lab's report on one specific batch, or lot, of a product. It isn't a brochure, and it isn't a promise about every vial ever made. It's a snapshot: this lot, tested on this date, by this lab, with these results.

That's why the details matter. Peptides are built one amino acid at a time, and the process can leave behind near-miss versions of the target molecule: chains missing an amino acid, chains with an extra one, or chains with a damaged side group.² A major review warns these impurities can skew early research results and lead to wrong conclusions.² A good COA tells you how much of that is in your lot.

1

lot per certificate

2

core tests: purity and identity

5

fields to check, every time

Some certificates go further. Net peptide content reports how much of the powder's weight is actual peptide, because a freeze-dried powder can also hold water and leftover salts from manufacturing.² Contaminant screens check for things like endotoxin, heavy metals or residual solvents. Those are a bonus. The five fields above are the minimum.

HPLC stands for high-performance liquid chromatography. The lab dissolves a tiny sample and pushes it through a column packed with material that holds on to different molecules for different lengths of time. A detector at the end draws a line with a peak for each component that comes out.

Your target peptide should be one tall peak, and impurities show up as small peaks around it. Purity is the main peak's area divided by the total area of all the peaks. So 99.62% means 99.62% of what the detector saw was the target.

One more catch: HPLC can tell you a sample is clean, but not what it is. A vial of the wrong peptide can still show a beautiful single peak. That's why the next test exists.

Every peptide has a known molecular weight, calculated from its amino-acid sequence. Mass spectrometry (MS) measures the actual mass of the molecules in the sample. If the observed mass matches the expected one, the lab has confirmed identity: the peak is the peptide it's supposed to be.

Regulators rely on the same tools. Official medicines-control labs pair chromatography with mass spectrometry to identify illegal and counterfeit peptide products. One published method screens for 25 different peptides in just 30 minutes.¹

The stakes are real. When Belgian public-health scientists analysed falsified peptide drugs from illegal online pharmacies, some peptide types came back at just 5% to 75% purity, and some products contained toxic heavy metals like arsenic and lead.⁴ A two-test COA, purity plus identity, is the simplest defence against that.

5–75%

purity found in some falsified online peptide products⁴

25

peptides one regulatory screen identifies¹

30 min

to run that screen¹

• No lot number, or a lot number that doesn't match your vial.
• Only a rounded minimum, with no measured purity figure behind it.
• No identity test. HPLC alone can't prove what the molecule is.
• No named lab, or a lab you can't find or contact.
• The same certificate everywhere: identical results across different products, lots or years.
• A suspiciously perfect 100.00%. Real instruments almost always find something.
• An old test date on stock that's supposed to be fresh.

A good supplier makes checking easy. The certificate should be public before you buy, not emailed after.

Every lot we sell is tested by an independent lab before it goes on sale. Its certificate is published in our COA library with the lot number, the exact HPLC purity and the name of the lab. Want to practise on a real one? Open the BPC-157 lab reports in another tab and check each of the five fields above.

We back it with a simple guarantee: test any batch at any lab you like, and if it doesn't match our report, you get your money back.