How to verify P21 is authentic

Step 1: Locate the batch number

Every Peptify P21 vial has a batch (lot) number printed on the label. Note this number down — it should match the Certificate of Analysis published on the product page for that specific batch.

Step 2: Download the COA from the product page

The batch-specific COA for your P21 is downloadable directly from the product page on peptifyuk.com. This is the most reliable verification method because the document is hosted under our control, tied to the batch number, and includes the original HPLC chromatogram image plus mass spectrometry data.

If a supplier does not publish batch-specific COAs or only provides a generic purity claim, that is a significant red flag.

Step 3: Check the HPLC peak

On the COA, look at the HPLC chromatogram. A genuine P21 sample should show a single dominant peak at the expected retention time, with purity >99% (peak area). The mass spectrometry section should confirm the molecular weight matches the theoretical mass of P21.

Any chromatogram with multiple large peaks, or where the purity percentage looks inconsistent with the visible peak, should prompt you to contact the supplier for clarification.

Buy P21 for research

99%+ HPLC-verified P21 in stock. Every vial ships from the UK with a batch-specific Certificate of Analysis. Same-day dispatch on orders before 1pm.

• P21 10MG

Frequently asked questions