What Is the Chemical Formula in Rolaids?

Rolaids is a brand of over-the-counter antacids -- drugs that help relieve acid indigestion and heartburn. Rolaids tablets are available in three varieties: Original, Extra Strength and Multi-Symptom. The latter variety is used to treat gas pain and discomfort. All three contain calcium carbonate and magnesium hydroxide as active ingredients.


Calcium carbonate, or CaCO3, and magnesium hydroxide, or Mg(OH)2, are basic or alkaline compounds and the active ingredients in Rolaids products. These compounds react with and neutralize some of the stomach acid in your digestive tract. The byproducts of these reactions are water, magnesium chloride, calcium chloride and carbon dioxide gas. According to the manufacturer, the Original product contains 550 mg of CaCO3 and 110 mg of Mg(OH)2 per tablet. Multi-Symptom and Extra Strength tablets contain 675 mg of CaCO3 and 135 mg of Mg(OH)2 per tablet.


Rolaids Multi-Symptom contains a third active ingredient, simethicone, which is a blend of polydimethylsiloxane and silica gel. Silica is silicon dioxide. Polydimethylsiloxane is a polymer in which each silicon atom is joined to two oxygen atoms and two methyl, or CH3, groups. Simethicone acts as an anti-foaming agent that helps your body to rid itself more quickly of gas caused by indigestion.

Inactive Ingredients

All three Rolaids products contain potassium acesulfame, or KC4SNO4H4, a compound often used as an artificial sweetener. Dextrose, C6H12O6, serves as an excipient, a compound that helps to bind the other ingredients together. Depending on the flavor, some Rolaids products contain sucrose or table sugar, C12H22O11; another inactive ingredient is corn starch, a polysaccharide, or long-chain polymer, of glucose molecules linked together like beads on a string.

Other Inactive Ingredients

The fruit flavor of Extra Strength Rolaids contains FD&C Yellow #6 Aluminum Lake. This yellow-colored dye is an aluminum salt of a sulfonated azo compound. Other dyes present in some of the flavored products include FD&C Red No. 3 or erythrosin, a disodium salt of 2,4,5,7-tetraiodofluorescein, FD&C Blue #1 and D&C Red #27. The peppermint-flavored Original product does not contain any dyes. Some flavors of Rolaids contain magnesium stearate, a magnesium salt of a common fatty acid called stearic acid.