Learn about the side effects of Tylenol PM (acetaminophen/diphenhydramine), from common to rare, for consumers and healthcare professionals. 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 contains two active ingredients: 500 mg of acetaminophen (a pain reliever) and 25 mg of diphenhydramine hydrochloride (an antihistamine that causes drowsiness). The combination is designed to relieve minor aches and pains while helping you fall asleep. 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. What it is: A combination of a pain reliever with a nighttime sleep-aid antihistamine (see the Drug Facts on each package). How to use: Always follow the on-pack directions and warnings. What to consider: Drowsiness is expected; set aside adequate time for sleep. Acetaminophen for aches, diphenhydramine nighttime sleep aid. Adults & 12+. Get safe TYLENOL® dosing guidance for adults and children. Learn about recommended TYLENOL® dosages, how to read dosing charts, and how to use acetaminophen safely. Read on for Tylenol PM dosage information, including typical dosage and what to do if you take too much. Shop TYLENOL PM Extra Strength Pain Reliever & Sleep Aid Caplets and read reviews at Walgreens. Pickup & Same Day Delivery available on most store items. 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.