Gelusil® is the #1 rescue treatment for immediate heartburn relief. For more than 70 years, Gelusil® has provided fast relief when heartburn symptoms flare up. Its unique combination formula is different from other antacids. It contains aluminum hydroxide and magnesium hydroxide to relieve heartburn and acid indigestion, and it has not been associated with acid rebound. Another active ingredient in Gelusil® is simethicone, which relieves bloating and gas.