Benylin Dry Coughs NIGHT Syrup is a medicine which is used to help provide night time relief of dry, irritating coughs and aid a restful sleep. The liquid contains diphenhydramine hydrochloride which is an antihistamine that helps relieve coughing and dry secretions in the nose and chest, dextromethorphan hydrobromide which is an antitussive to help stop coughing and levomenthol which helps you breathe more easily by relieving congestion. The medicine is for use in adults and children aged 12 years and over.