Panadol Night contains two active ingredients, 500 mg of Paracetamol which is an analgesic (a pain reliever which relieves aches) and antipyretic (reduces body temperature when you have a fever) and 25mg of Diphenhydramine hydrochloride, an antihistamine with additional sedative properties. Diphenhydramine is an antiallergic which relieves allergy symptoms like runny nose, watery eyes and sneezing. Paracetamol is an analgesic (pain reliever) and an antipyretic (fever reducer). It blocks the release of certain chemical messengers in the brain that are responsible for pain and fever. Panadol Night also temporarily relieves fever and aches and pains associated with cold and flu which causes difficulty in sleeping, so you can have a good night sleep.