Gaviscon Double Action Liquid Sachets Gaviscon Double Action Liquid Sachets get to work instantly to effectively relieve heartburn & indigestion & last up to 2x longer than antacids. The powerful formula contains two antacids & an alginate to quickly neutralise excess stomach acid to relieve pain & discomfort & to form a protective barrier over the contents of the stomach to help prevent acid coming back up into the oesophagus (food pipe). Gaviscon Double Action Liquid Sachets are suitable for use during pregnancy & breastfeeding. How Gaviscon Double Action works (video).