Peptryn
Rank 1 of 3. Documentation score 6 of 6.
Complete public paperwork for the products we checked.
What the documents show
Publishes a COA library of 16 certificates. Each entry lists a lot number, a purity figure and an endotoxin or identity result.
Source: peptryn.com/coa/Names its testing lab, MZ Biolabs, and links each COA to a report hosted on the lab's own site. The Retatrutide 10mg COA lists HPLC-UV-MS, 99.62% purity and a negative endotoxin result. The report link loaded when we tested it.
Source: peptryn.com/coa/retatrutide-10mg/Says you can scan the QR code on the vial, or search the printed batch number on its lab results page.
Source: peptryn.com/lab-results/Says each batch is tested in-house, then verified by an independent US laboratory before it ships.
Source: peptryn.com/
What we could not confirm
Two COAs list an identity result instead of an endotoxin result, so the tests are not identical across products.
The library listing shows no test dates. The one date we found sits inside the report link (24 June 2026).
We did not read the full lab reports or contact MZ Biolabs, so we have not confirmed the lab issued them.
Details
- Lab named
- MZ Biolabs
- Method
- HPLC-UV-MS
- Purity
- The site claims 99%+ purity. The three COAs we read show 99.62%, 99.78% and 99.97%.
- Company
- Peptryn, 867 N 2nd St, El Cajon, CA 92021
- Affiliate program
- 20% commission per referred sale
- Checked
- 21 September 2026, from the vendor's public pages
These are the vendor's claims and our observations. We have not tested any product. Research peptides are sold for laboratory research only and are not for human consumption.