I have worked in LTC and a few of the elderly women will ask for tylenol to help them sleep and it works for them. My mom use to call it her "dream pills" . If she was having trouble sleeping she would take two tylenol and the next morning she would wake up refreshed having a good nights sleep and she was not elderly she was only in her fifties. I guess meds work different on different people. My mom would not take medicine unless it was absolutely necessary so I guess her body wasn't immune to the effects of tylenol. If a person was routinely taking stronger meds the tylenol would probably not be effective in my opinion.:)