Strepsils Original lozenges provide more than just soothing relief, the two active ingredients have proven antibacterial and antiviral activity against some bacteria and viruses causing sore throat. They relieve the pain of sore throat fast from the first signs and continue working long after the lozenges has gone, for up to 2 hours. Dose: Adults and children 6 years and over : Dissolve one lozenge in the mouth every 2 to 3 hours.