Nytol is used to relieve short term sleeping difficulties nytol contains the active ingredient diphenhydramine hydrochloride which is an antihistamine that cause sleepiness or drowsiness sleeping difficulties can be caused due to many reasons such as jet lag stress personal problems and by taking nytol it is an aid to a good nights sleep nytol has been proven to help you fall asleep faster and have a longer deeper sleep leaving you feeling fresh and rested in the morning