Quick help for a feeling of fullness, stomach pressure and heartburn Rennie FRESH provides quick and well-tolerated relief for heartburn, a feeling of fullness, stomach pressure, acid reflux and other acid-related stomach complaints. Heartburn, stomach complaints or acid reflux are usually caused by too much stomach acid. Rennie relieves the symptoms of heartburn quickly and easily using the proven combination of active ingredients made from calcium and magnesium carbonate. The proven remedy for heartburn works on the spot: It reliably neutralizes the excess stomach acid and converts it into water and other natural substances. Sugar-free formulation with an intensely fresh mint flavor. Due to its good tolerability, Rennie FRESH is also suitable for pregnant women.