You can still take prescription medication/vitamins prescribed by a legitimate doctor (you can’t pay them or otherwise influence them to prescribe you things you don’t really need, and you have to use it as directed).
Same goes for over the counter stuff. You can take cold, sleep, allergy, pain etc. medicine, but you actually have to have a cold, have trouble sleeping, have allergies, have pain, etc. and use it as directed. And no combining brands/medicines either.
Basically no more using mind-altering substances for fun or relaxation anymore for $250k a year. Take anything you aren’t supposed to and you’re dead. Can’t go back on it.