I’m going to answer the Constitutionality question. According to Madison in the 42nd? Federalist, the interstate commerce clause was put in place to give the government the power to stop one state from charging tariffs on goods from other states that re simply passing through their state and things like that. The language is unfortunately overly vague and i would venture to say that that may have been the doing of Alexander Hamilton. It was not put in place to regulate production of individual goods simply because that good happens to flow from state to state. Think trade policy not individual trades.
Of course the FDA is itself no where found in the enumerated powers.