I think the Commerce Clause is a pretty sound basis for most FDA regulation.
It just gets weird with the overbroad supreme court decisions that are like: "well, stuff that only happens in a single state but that might be used for interstate commerce or somehow impact interstate commerce indirectly" is also covered. [1][2]
One can only get from regulating interstate commerce to telling a terminal patient what medicine he may consume by a tortured logical process driven by motivated reasoning.
