Stupid question: how do you know whether what is in the vial matches the label at all?

Reference ranges differ between labs, so comparing two reports is close to meaningless.

Personal experience, labelled as such, is exactly right here. Nobody is prescribing.

Same here.

Name the active ingredient, not just the brand. It makes these threads searchable years later.

Domain age is one of the few signals that is expensive to fake and free to check.

Test one thing at a time. It feels slower and it is the only way to learn anything.