Well, I reckon there's better ways to commit suicide than destroying your liver, but it fits the 14 year old mentality.
Acetaminophen (aka Paracetamol, Tylenol) is dose sensitive, in that the body can only fully metabolize a limited dose at one time. When someone overdoses, the body partially metabolizes it into a hepatoxin (liver poison). It does much the same as eating a toadstool or other similarly poisonous fungus.
I still prefer to use Acetaminophen over aspirin or other Nsaid based products for pain relief. In the right dose it is much safer, especially taken on a regular basis. Ibuprofren is a better anti-inflammatory and fever reducer, and aspirin has it's cardio benefits, but there are inherent risks with those that seem a bit more common than any from Tylenol, at least from my experience.
It is nonetheless prudent to know what is in the OTC meds you take, lest you end up overdosing yourself unwittingly.
I think the current recommended adult dose for Tylenol is 1/4 the LD 50/50 for acetaminophen, IIRC. That is a pretty good margin.
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The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)