Answering the narrow version, because the broad one does not have a single answer. Prices dramatically below market are the strongest single signal, and the reason is arithmetic rather than suspicion. Synthesis, testing, and cold-chain shipping have floors. A price well under the floor means something was skipped, and the two things that get skipped are testing and content.

I would rather be corrected than agreed with, if it comes to it.

Dr.NateNeph said:

Prices dramatically below market are the strongest single signal, and the reason is arithmetic rather than suspicion.

Right, and one flattering data point from a group buy is not consistency. Consistency means separate batches, separately commissioned, over months.

PharmHunterJen said:

The list price and the price I actually pay differ by a factor of six depending on which of four routes I use, and none of that is transparent from…

Agreed, with a caveat about community reputation: it is a lagging indicator. Reports arrive weeks after orders, so a supplier can look excellent for a month after quality has already changed.

Adding the clinical framing, because it changes how the question reads.

Insurance update relevant to cost and coverage: I just got my prior auth approved through UnitedHealthcare after 3 attempts.

What finally worked: a letter from my endocrinologist documenting BMI history (>3 years), failed diet attempts, comorbidities (sleep apnea + prediabetes), and referencing the SELECT trial data.

If your PA keeps getting denied, don't give up. Request a peer-to-peer review between your doctor and the insurance medical director. That's what finally broke through for me.