Right. And I think the parent asked a really good question: isn't the power of regulating what foods and drugs are safe for the populace to consume a responsibility that was delegated to the USFDA, not the DEA?

If the DEA does have this power … isn't there overlap between the FDA and the DEA?

the answer is simple: the FDA is not a police agency and the DEA is.

their domains overlap because the prohibition culture of the U.S. government does not treat "drugs" rationally (i.e. as if they were simply medicines) but rather has tied the entire concept up in a gordian knot of fear, racism, social engineering, and in-group selection.

similarly, alcohol and tobacco, despite obviously being "drugs" even according to the logic of the federal government bureaucracy, are given their own police agency as well, because the DEA was tasked with persecuting hippies and brown-skinned people, whereas the ATF was tasked with shooting up disobedient white people.

I believe the DEA is part of the Justice Department and serves the executive branch.

The FDA is part of the Department of Health and Human Services, also serving the executive branch.

Sorry, I don't know, but it is a good question, about what policy determines, which department is responsible for what.