This is pretty misguided.A casual mistake like forgetting your cough syrup has acetaminophen can easily cause an overdose and then you fucking die. That’s not the risk profile you want for “most people in most circumstances”.
Yeah this is optimizing for the good case instead of tail risks and mistakes and we see too many overdoses already.
Of course, we could press the fix this immediately button by requiring acetaminophen to be sold mixed with NAC but that would be too easy.
500mg from a capsule and 500 from cough syrup 4 times a day is still fine. With a 100% safety margin still.
If you’re taking more meds than that without clinical supervision Id say something is wrong in the system or your medicine practices.
Where I’m from it’s common to walk to the nearest pharmacy and get meds when needed. Even over the counter stuff like paracetamols. And talking to the pharmacist. They’ll ask what you’re already taking and tell you what else to get.