A vendor grading its own product has a conflict of interest. Here's why an outside lab with no stake in the sale is the only fully credible source — and how to confirm the lab is real.
Not all "tested" claims are equal. There is a meaningful gap between a vendor that tests its own product and a vendor that pays an outside lab with no financial stake to do it. Both may print a certificate. Only one removes the conflict of interest.
We are an independent comparison site, so we will be blunt about our own bias: we think independence is the most reliable quality signal in this market. A named outside lab is putting its own reputation behind the result. A vendor grading itself is not.
This is the same logic that makes a neutral referee more credible than a player calling their own fouls — which is exactly why a third-party site explaining third-party testing carries more weight than a vendor doing it. Independence, all the way down.
A COA is only as trustworthy as the lab that signed it. Before you accept one, spend two minutes verifying the lab exists and is independent:
What this looks like when a vendor gets it right. The bar isn't complicated, which is why so few clear it. As a worked example: Onyx Biolabs names its testing partner outright (Kovera Labs), runs both HPLC and mass spectrometry on every batch rather than one or the other, publishes the certificates on a public results page instead of "on request," and verifies net content — so a 10 mg vial is confirmed to actually hold 10 mg. That last one directly answers the underdosing problem, and almost nobody does it. Whether or not you buy there, use it as the standard you hold other vendors to.
Independent testing is one of the heaviest factors in how we score. Once you know what quality looks like on paper, the next step is finding vendors that actually meet the bar. That is exactly what our rankings measure.
Last reviewed July 2026. By the Peptides Uncaged Research Team. For research and educational purposes only.
Honest peptide breakdowns, vendor updates, and new-research alerts. No spam, ever.