Sominex Tablets are one a night tablets that contain the active ingredient, Promethazine Hydrochloride, which induces drowsiness and is safe and effective in helping you to fall asleep. Sominex can help if your suffer from sleep disorders, insomnia or if your are suffering from changes in your normal sleep pattern (e.g. Jet Lag). It helps to turn off the body's Awake System and helps you relax and fall asleep. Sominex helps to provide approximately six to eight hours of restful sleep.