TUMS Ultra Strength Chewable Antacid Tablets go to work in seconds by starting to neutralize acid on contact to bring fast and powerful ultra strength heartburn relief, with 33 percent more acid fighting power per tablet (compared to Extra Strength TUMS). When symptoms occur, chew and swallow two to three ultra strength tablets, depending on the severity of your acid indigestion. Featuring the active ingredient calcium carbonate, these chewable antacids relieve heartburn, sour stomach, acid indigestion and provide upset stomach relief associated with these symptoms. Delicious and fast, these TUMS Assorted Fruit antacid tablets include a variety of tasty flavors.