We don't have tylenol here where I live, so I'm not sure whether its a actually a sleep aid or a night time pain reliever,...but I'd agree everyone needs to be careful of paracetamol/acetaminophen, particularly if you've already given your liver enough work over the years.
Also remember, over the counter stuff is not meant to be for prolonged use, so if the insomnia is chronic, please see a Dr.
and...here's a few non medical tips:
Insomnia? 42 Simple Tips to Help You Get to Sleep - Insomnia treatment, cures
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