TUMS Smoothies Chewable Extra Strength Antacid Tablets work in seconds so you can forget your heartburn and get back to the moments that matter. They contain 750 mg of calcium carbonate (naturally sourced) to quickly and effectively fight heartburn and relieve sour stomach, acid indigestion and upset stomach associated with these symptoms. These smooth-tasting and delicious, fruit-flavored antacid tablets neutralize acid on contact, giving you fast extra-strength heartburn relief. Adults and children 12 years and older may chew two to four antacid chewable tablets as symptoms occur or as directed by a doctor. Antacid tablets come in a resealable bottle that is easy to take on-the-go in a purse or pocket so you're ready when heartburn strikes.