This page explains exactly how a supplier's trust grade is calculated on CompoundSearch — the inputs, the weights, and the grade scale — so it can be checked rather than taken on faith. For how a supplier gets listed at all and how the site makes money, see /trust.
A supplier's score is built from four weighted inputs, based on their actual Certificates of Analysis — not their marketing copy.
Batch-specific COA
Does the Certificate of Analysis actually tie to a specific batch or lot, or is it one PDF from one good test reused across every product on the site indefinitely? A COA with no lot number doesn't tell you anything about what you're actually buying — it's the single biggest factor in the score.
Named third-party lab
Was testing done by a named, independent lab whose results can be checked against their own database (Janoshik Analytical is a common example in this space), rather than an unnamed or in-house lab whose findings can't be verified by anyone outside the supplier.
Safety panel beyond purity
Most published COAs report HPLC purity and stop there. Does testing also cover heavy metals, microbial contamination, and endotoxins — the things that actually determine whether a sample is safe, not just how concentrated it is.
Direct verification
Has CompoundSearch personally confirmed something with the supplier directly (a reply, a document, a specific batch sent on request), rather than only relying on what they publish about themselves.
The four weighted inputs add up to a score out of 100, which maps to a letter grade:
A grade only appears once someone has actually sat down with a supplier's real COAs and confirmed each of the four inputs above. Right now that's 0 of 8 suppliers — everyone else shows "not yet reviewed" on /trust. That label means exactly what it says: the review hasn't happened yet, not that anything is wrong. Nothing is scored by guesswork, and no supplier can pay to change or skip this process.