Sominex Tablets are specifically designed to help induce a healthy night\'s sleep, especially if you are having trouble to drift off into a peaceful sleep due to stress, interruption to your normal sleeping routine, jet lag, or a change in lifestyle. These tablets helps to relieve occasional disturbance in your normal sleep pattern. Sominex contains the active ingredient Promethazine Hydrochloride. This is a sedating antihistamine similar to the medication given to those with allergies. It allows you to fall asleep and will provide a deeper state of sleep leaving you feeling rested and refreshed when you wake up. Key features of Sominex tablets Suitable for those who find it hard to drift off to sleep Suitable for those experiencing an interruption to their normal sleeping routine Contains the active ingredient Promethazine Hydrochloride Could provide a deeper state of sleep Wake up feeling rested and refreshed How quickly does sominex work? Promethazine will start to make you feel sleepy in around 20 minutes after you take it and may work for up to 12 hours. If you\'re taking it for a cough or cold, allergies or nausea, your symptoms should start to improve within 20 minutes. The medicine should work for around 4 to 6 hours.