ACTIVE INGREDIENTS: This product contains famotidine 10 mg (an acid reducer), calcium carbonate 800 mg and magnesium hydroxide 165 mg (both of which are antacids). Compare to the active ingredients in Pepcid Complete EFFECTIVE: Acid Reducers like Dual Action Complete, Famotidine 10 mg/Calcium Carbonate 800 mg/Magnesium Hydroxide 165 mg Tablets (Chewable) can relieve heartburn due to acid indigestion and sour stomach HEARTBURN occurs when stomach acid backs up into the esophagus—the muscular tube that carries food and liquids from the mouth to the stomach. A heartburn medicine like Dual Action Complete helps provide heartburn relief. MANAGING HEARTBURN: In addition to using Dual Action Complete or another heartburn medicine, these tips can also help with heartburn relief: do not lie flat or bend over after eating; do not eat before bedtime; eat slowly and avoid big meals. TYPES OF HEARTBURN MEDICINE: Antacid tablets help to treat mild heartburn (indigestion). Proton pump inhibitors (PPIs) are used to treat frequent heartburn. H2-Blockers like Dual Action Complete work as acid reducers to help relieve heartburn.