★★☆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 carry a full 50 mg sleep-aid dose
They deliver 50 mg of diphenhydramine hydrochloride alongside 1,000 mg of acetaminophen, and the label forbids any other diphenhydramine product, including a skin cream.
What the study found
A night-time pain pill carries a full sleep-aid dose of antihistamine
Two Tylenol PM Extra Strength caplets at bedtime deliver 50 mg of diphenhydramine hydrochloride, the same amount as two capsules of a dedicated sleep aid, alongside 1,000 mg of acetaminophen. The label forbids taking it with any other diphenhydramine product, including a skin cream.
The caveat · Label is silent on the next morning
The label tells users not to drive while taking it and says nothing about the following morning, which is where the driving evidence sits. One product from one manufacturer in one country.