Frequently asked questions
How we score, what we measure and what we don't, and how to use this European comparison.
How do you calculate the score?
Each vendor is scored across 19 weighted criteria in five axes: product quality, testing breadth, service, accessibility and transparency. The formula is public and applied equally to all. The score is computed automatically from recorded evidence, never adjusted by hand.
Does quality depend on how many tests a vendor publishes?
No. We separate measured quality (the level and rigour of certificates) from breadth (how many lots have been analysed). A vendor with a single verified 99.7% certificate has top quality even if its breadth is low. The number of tests is scored separately and with less weight.
Is a 99% always a 99%?
No. We weight purity by test rigour: a 99.7% from a recognised independent lab, verifiable on its own domain and recent, is worth more than the same number with no verifiable lab or a year old.
Why are some well-known vendors missing?
Our main ranking is European: it only includes vendors with real EU operation or shipping. Several globally-cited vendors only ship within the US, so for the European buyer they are not an option. We show them separately, as reference.
How do I verify a certificate myself?
Look for the lab's name and a verification key or QR, and confirm the link goes to the lab's own domain (for example verify.janoshik.com), not the vendor's store. If it can't be verified at source, treat it as a claim, not a fact.
Who operates this site?
CheckPeptides is operated by a team active in the peptide market, including one of the brands listed here. That is why every rating links to source evidence: we don't ask you to trust us, we give you what you need to check.
Do you accept payments from vendors to improve their score?
No. The score comes from publicly verifiable evidence; no vendor can pay to raise its rating. The weights are published and applied equally to all.
How often do you update the data?
Each review carries its verification date. We re-verify periodically and when a vendor publishes new certificates. If you spot an outdated data point, the linked source lets you check the current state.