0) generally recognized as safe and free of containments - it won't kill you and you get what is on the label. This should be applied and enforced through some kind of mandatory batch testing. Supplements desperately need this because you really have no idea about what you're getting.
1) Plausible Efficacy - this is 0 plus a plausible efficacy for the marketing claim. I.e there is some mechanism of action or reasonable amount of evidence this could work. Marketing would have to make this clear. Most OTC medications should be under this standard.
2) FDA proven efficacy - this is the highest standard of proof, basically the current standard. Prescription medications should be held to this standard.
maybe 3) YOLO/Emergency/Terminal illness authorization - can't be marketed, only listed in a government index and you need a DR co-sign and acknowledge that it may kill you, is unproven and the outcome is recorded for the purposes of later study.