Answer
It may not be. Sodium content varies between products and can be substantial, so check the exact formulation.
Sources for this answer
- Acidex Oral Susp/Boots Peppermint Flavour/Peptac Peppermint Liquid/Tesco/ Well Pharmaceuticals Heartburn and Indigestion Oral Susp Peppermint Flavour, Rennie Liquid/Care Heartburn Relief Oral 0027 — Current selected SmPCemc · Summary of Product Characteristics
- Gaviscon Double Action Liquid Sachets — Current selected SmPC