Learn about Tylenol PM Extra Strength (acetaminophen / diphenhydramine) usage and dosing. Read the latest news and reviews about the drug as well as potential side effects and popular alternatives. Tylenol PM combines acetaminophen and diphenhydramine. Here’s what each ingredient does, their side effects, and safe dosage limits to keep in mind. TYLENOL® PM is specifically formulated for minor aches and pains with accompanying sleeplessness. Its combination of acetaminophen and a nighttime sleep aid relieves minor pain and helps you fall asleep. Here’s a closer look at Tylenol PM, its recommended use, and potential side effects. Tylenol PM combines a proven pain reliever and sleep aid to help you fall asleep faster and stay asleep through the night. Effective, non-habit forming relief. Tylenol PM is a combination medicine used to treat occasional insomnia associated with minor aches and pains. Tylenol PM is not for use in treating sleeplessness without pain, or sleep problems that occur often. Tylenol PM (acetaminophen / diphenhydramine) is a combination over-the-counter medication used for short-term relief of minor aches or pains that cause trouble sleeping. The typical Tylenol PM dosage is 2 caplets or 30 mL (2 tablespoonfuls) by mouth about 30 minutes before bedtime.