Rennie Peppermint is an antacid tablet that neutralises excess stomach acid to relieve the symptoms of heartburn and indigestion. Rennie Peppermint tablets contain magnesium carbonate and calcium carbonate, which work together to create an antacid that neutralises stomach acid. Excess acid in the stomach causes heartburn, dyspepsia, hyperacidity, flatulence, upset stomach and all forms of indigestion. Rennie is a fast-acting and effective remedy that has been trusted for decades for the rapid relief of heartburn and indigestion. Many people suffer from heartburn and indigestion and symptoms range from pain and discomfort to burning chest pains and bloated stomach.