Gets to work in 2 minuteslong lasting reliefextra relief from heartburn amp indigestion174 rennie is a registered trademarkcalcium carbonate magnesium carbonate alginic acidrennie extra tablets provide relief from heartburn and acid indigestionrennie extra tablets work in two different ways1 alginic acid forms a protective barrier in the stomach to stop acid escaping upwards soothing that burning pain in your chest2 c