Supplements. Even the ones that seem to have some scientific validity for their intended purpose aren't dosed correctly and are often mixed with all kinds of unhealthy filler material depending on the source.
Ehh, "supplements" are just the operationalization (assembly-line-ization) of people consuming herbs for medicinal purposes. People have always done that, and I expect will always do that. Inconsistent dosing and random side-products are inevitable consequences, but nobody seems to mind.
Though, I'm surprised there isn't a small movement of "home pharmacologists" who buy herbs (or supplement pills/powders) and then distill/reflux/recrystallize out the active ingredients and re-portion them into dosing media for their own use.
