> If I have some novel medical compound, of course I can't just mix it into my cookies.

Why of course? What justification leads you to "of course" here. Not saying you are necessarily wrong but doesnt sound like say taking aspirin and adding some vitamins, despite now being a novel medical compound, would make it immediately and obviously illegal, letalone for personal use in cookies or otherwise.

Not that the law ever had to or indeed does make sense.