Trust infrastructure first
Look for catalog-wide, per-lot COAs from a named independent lab, available before you buy and not gated behind order size. A single hero-product COA, or COAs only unlocked after a large order, is a red flag.
Check whether the headline claims match the fine print. The most common failure in this category is a bold guarantee (or purity claim) that a deeper policy page quietly contradicts.
Consistency is the tell
A trustworthy site states one guarantee, one purity standard, and one stacking/discount policy, and repeats them identically everywhere. When the number on the homepage differs from the number in the cart, that inconsistency is the signal.
Apply it here too
We hold ourselves to this list: the guarantee number, shipping terms, and lab data on this page are authored once and reused across the whole site, and the Lab Results hub is open to anyone before purchase. If you find an inconsistency, it's a bug, not fine print.