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Certificate of Analysis

Every Peptide.ST batch ships with a Certificate of Analysis. Enter the batch/LOT number from the A6 or A4 paper included in your package (it looks like PST- or PT-12345678) to confirm it is genuine and view its lab details. You can also browse every active batch below.

Expiry shown as MM/YYYY · COA date as DD/MM/YYYY. A number that does not match is not an active Peptide.ST batch. Contact support if you believe this is an error.

Batch Library

Every active Peptide.ST batch, lab-tested and documented. Open any certificate to view the full analysis and save it as a PDF.

Vials Created

Documented production across every active batch. Each run is quality-controlled and tied to its own Certificate of Analysis.

What Happens When a Batch Fails

Testing only means something if a failed batch actually gets stopped. Here is exactly what we do when one does not meet our standard, and why it happens more often than people think.

98.5%Minimum purity

Below 98.5% purity, the batch is destroyed

We do not make exceptions, quietly discount it, or sell it off as a lower grade. If a batch comes back under our threshold, it is written off and destroyed. Only batches that pass are ever filled into vials and shipped.

Every batch tested

HPLC and mass spectrometry run on each batch before anything is released.

Fails are destroyed

Anything under 98.5% purity is discarded, never sold at a lower grade.

In-house lab

We work directly with our own laboratory in Poland, batch after batch.

Does it happen? Yes

More often than people think. A failed batch is just part of making these compounds.

Yes, batches really do fail, and more often than most people realise. Purity is not something you can just guarantee up front. Peptides are built one amino acid at a time on a synthesizer, and at every single coupling step there is a small chance the chain does not extend perfectly. Across a thirty or forty step sequence, those tiny probabilities stack up into real impurities: deletion sequences missing a residue, truncated chains that stopped early, and closely related by-products that are chemically almost identical to the target.

Cleaning those out is the hard part. Purification separates the good chains from the near misses, but the longer and more complex the peptide, the harder they are to pull apart, and the more product you lose chasing a higher number. Humidity, reagent quality, temperature, and even the specific sequence all move the result. That is why an honest lab will tell you two batches of the same peptide can test differently, and why a real 98.5 percent plus result has to be measured, not taken for granted.

So when a batch misses, we do not force it through. We destroy it and make the next one. Sticking to that rule is what makes a Certificate of Analysis from us mean something, and it is why our own name goes on every report instead of someone else's.

Why our COAs are our own

The honest reasons we test in-house instead of paying for third-party COAs.

Read more

FAQ

Common questions about our batches, packaging, testing and storage.

Why do some caps have a different color?
Cap colour is purely for quick visual identification. It lets us, and you, tell compounds and batches apart at a glance in storage. The colour carries no other meaning and does not affect the peptide inside the vial.
Why does my vial ship with no cotton packaging?
Lyophilized peptide is stable and does not need cotton filler to survive transit. We leave it out to keep packaging lean, discreet and less wasteful. Every vial is still secured with protective padding so it arrives intact.
How do you manage your storage?
Everything is held in our own warehouse in two 1,000 litre freezers kept at -20 °C, desiccated, right up until dispatch. This keeps every batch at full stability from production to the moment it ships.
Do you also test your BAC water?
Yes. Every batch of bacteriostatic water is checked for sterility and the correct 0.9% benzyl alcohol concentration before it is released for shipping.
How do I verify my batch is genuine?
Enter the batch/LOT number from the A6 or A4 paper included in your package (it looks like PST- or PT-12345678) into the verification box at the top of this page. It pulls up the matching Certificate of Analysis. You can also view every active batch on peptide.st/coa. If a number does not match, it is not an active Peptide.ST batch.
How should I store my peptides after they arrive?
Keep lyophilized vials at -20 °C and away from light. Once reconstituted, store them refrigerated at 2 to 8 °C and use within the recommended window for that compound.