Active Ingredients:Per Tablet: Calcium Carbonate 400 mg. Find the right dose on chart below based on weight (preferred), otherwise use age. Repeat dose as needed. Do not take more than 3 tablets (ages 2-5) or 6 tablets (ages 6-11) in a 24-hour period, or use the maximum dosage for more than two weeks, except under the advice and supervision of a doctor.