Strepsils Sore Throat and Blocked Nose menthol lozenges rapidly soothe and refresh the nose and throat. It is one of the first line of defense against cold and flu symptoms. They contains antiseptic medicines to help cleanse the throat and fight infections. Strepsils Sore Throat and Blocked Nose menthol lozenges relieve sore throat fast (within 5 minutes), which lasts for long after the lozenge has gone, up to 2 hours, coupled with a vapor action to help relieve nasal congestion. Dose: Adults and children 6 years and over : Dissolve one lozenge in the mouth every 2 to 3 hours.