The amount and duration needed to see side effects with ibuprofen is much more compared to acetaminophen. Look at the actual research and the amounts and durations studied. Ibuprofen is ridiculously safe if you're outside particular known risk groups, and often even then. Generalized side effects like hearing loss are far preferable to, e.g., the deaths that acetaminophen regularly causes. But AFAIU hearing loss is exceptionally rare even for heavy users.

My father fell off a roof, feet first, onto hard clay and shattered his feet. Doctors said he'd never walk again and it took awhile to find and cajole a doctor to pin his bones back together. He's been on his feet for well over ten years.

The pain is still excruciating, though. 24/7. He refuses prescription pain medication, and has been eating ibuprofen like candy for the entire time. His hearing is bad, but not much different than typical old-man hearing, especially considering he used a skill-saw for most of his life.

There are plenty of bad things ibuprofen is capable of. But the point of my anecdote is that the actual risk is, relatively speaking, much less than you'd think. Consumer warnings lead us to equivocate risks when in fact relative risks can be worlds apart. Look at the actual studies and make informed decisions. I'll run things past a doctor or pharmacist for anything serious or if it involves a child, but 9 times out of 10 they'll know nothing more than the literature and the commonly understood exceptions and unknowns. They always give me the thumbs up for my over-the-counter, make shift drug formulations.

Regarding acetaminophen, I always told my wife during her pregnancy that she should only take as little as necessary, if at all, but of course she shouldn't needlessly suffer. I'm only just learning about this new research, but it's been obvious to me that the safety of acetaminophen has largely been based on a lack of contrary evidence and by the level of comfort that comes with group-think. Like Microsoft, nobody ever got fired for prescribing Tylenol (the brand name in the U.S.). In medicine absence of evidence often is evidence of absence, but only in so far as people have been paying close attention, and only in so far as alternatives have been explored.

But ibuprofen has gotten an undeserved bad rap in the U.S., and in some other countries requires a pharmacists' prescription. That's ridiculous. It seems we're much too risk adverse when it comes to ibuprofen, while dramatically underestimating the risk of acetaminophen. If anything the situation should be the reverse. OTC acetaminophen causes incredible harm. The biggest risks for ibuprofen relate to interactions with other, invariably prescription, medicine, and so there's ample opportunity to inform people to avoid ibuprofen.

Some people would like laws to restrict the sale of both. IMO trying to bifurcate medicines into safe-at-any-dose, OTC and prescription medicine has caused caused both medical professionals and regular consumers to lose our critical faculties. It's caused OTC medicines to become ineffective. And it's caused prescription medicines to become too widely prescribed and abused when people and situations fit the letter of the marketed indications. In both cases professionals and non-professionals aren't thinking as critically as they should, and aren't taking into account how little we actually often know about this stuff. It also substantially increases the cost of care.