While it might not seem so at first, suicide by tylenol is actually pretty hard to accomplish.

You're gonna have a hard tike dying. In more ways than one:

The symptoms are excruciating and start at 7 grams. That'd be 28 standard tablets or 14 high-dose ones. It takes a long time for it to kill you, so even with the right dose, it'll be hours of agony. Stuff like convulsions and excrutiating pain, mostly in the stomach. In the later stage as the liver fails, you turn yellow and feel even more unwell, often with vomiting (but by then the drug's probably been absorbed).

That being said, 7 g is not nearly enough to do any real damage. LD50 in mice is 2 g per kg of body weight, which comes to 280 high-dose tablets for the average adult. That's a giant box of skittles. A box which you need to down fast, before the horrible symptoms kick in and dissuade you from continuing. However, mice aren't humans, so the dosage information is probably not too precise. In any case, the difference between the unpleasant dose and a lethal one is huge.

Even if you were to do this, chances are someone will find you and you'll end up in the ER. A basic tox screen will quickly reveal the cause, and you'll be detoxed promptly. And after a liver transplant, chances of surviving are high - assuming you took a large enough dose to warrant one.

All in all, the death rate from tylenol poisoning is 0.1%. That does include accidental ones as well (which cause no real damage), so the statistic for actual suicide attempts is higher, but not by much.