★★☆Single study — solid evidence, such as one good trial or a large observational dataset, but not replicated at the top tier.
Two Tylenol PM caplets are a quarter of the acetaminophen limit
Two caplets at bedtime carry 1,000 mg of acetaminophen, against the 4,000 mg in 24 hours the label names. The warning is about a second acetaminophen product on top.
What the study found
Nightly Tylenol PM is a quarter of the liver warning, not all of it
Two caplets at bedtime is 1,000 mg of acetaminophen, against the 4,000 mg in 24 hours the label names as the point where severe liver damage may occur. The hazard it actually warns about is a second acetaminophen product on top: a cold remedy, a headache tablet, a prescription painkiller.
The caveat · How often people stack is unknown
This is what one US label states, not a measurement of harm. Nothing here counts how often people do stack a second acetaminophen product on top, only that the label names it as the thing to avoid.