Each AdvilPM caplet contains 200 mg of ibuprofen and 38 mg of diphenhydramine citrate, a gentle sleep aid Ibuprofen relieves pain over several hours while the diphenhydramine helps you get a full nights sleep. Combination of these ingredients not only reduces your pain it shortens the time it takes to fall asleep and increases the duration of your sleep The result: a better night"s sleep.