Maalox is a liquid antacid containing aluminum hydroxide (200 mg), magnesium hydroxide (200 mg), and simethicone (20 mg) per teaspoon. Several products share this exact formula, and other antacids work differently but treat the same symptoms. Your best substitute depends on whether you want an identical match or simply effective heartburn and indigestion relief.
Products With the Same Ingredients
Mylanta is the closest match to Maalox. It contains the same three active ingredients: aluminum hydroxide, magnesium hydroxide, and simethicone. Gelusil is another brand with this identical combination. Both neutralize stomach acid the same way Maalox does and include simethicone to reduce gas and bloating. If your goal is a direct substitute, either of these will behave almost identically in your body.
Store-brand and generic versions of “antacid plus anti-gas” liquids also use this formula. Look at the “Active Ingredients” panel on the back of the bottle. If it lists aluminum hydroxide, magnesium hydroxide, and simethicone, it’s functionally the same product as Maalox regardless of the brand name.
Calcium-Based Antacids Like Tums
Tums and similar chewable tablets use calcium carbonate instead of aluminum and magnesium. They work quickly, raising stomach pH within about 10 minutes of chewing. Maalox tablets reach the same level in roughly 40 to 80 seconds in lab testing, though real-world differences depend on whether you’ve eaten recently.
The bigger distinction is how long relief lasts. High-dose chewable calcium carbonate can keep stomach acid suppressed for up to three hours, but swallowable calcium carbonate tablets may wear off in as little as 5 to 35 minutes depending on the dose. Maalox tablets, by comparison, maintained a higher pH for roughly 30 to 55 minutes in controlled testing. Both are reasonable for occasional heartburn, but the duration can vary quite a bit with calcium-based products.
Calcium carbonate tablets are widely available, inexpensive, and easy to carry. They also provide a small amount of dietary calcium, which some people consider a bonus.
Acid Reducers That Work Differently
Antacids like Maalox neutralize acid that’s already in your stomach. Two other classes of over-the-counter medications take a different approach: they reduce the amount of acid your stomach produces in the first place.
H2 blockers (sold as famotidine, the active ingredient in Pepcid) block a specific signal that tells your stomach to make acid. They take longer to kick in than a liquid antacid, usually 30 to 60 minutes, but their effects last significantly longer, often 8 to 12 hours. If you get heartburn predictably after meals or at night, an H2 blocker can prevent it rather than just treating it after it starts.
Proton pump inhibitors, or PPIs (sold as omeprazole, the active ingredient in Prilosec OTC), shut down the acid-producing pumps in your stomach lining more completely. They take one to four days of daily use to reach full effect, so they’re not a substitute for the quick relief Maalox provides. PPIs are designed for frequent heartburn occurring two or more days per week, not occasional flare-ups.
Some people use a liquid antacid for immediate relief while an H2 blocker or PPI builds up its longer-lasting effect. These are complementary tools, not necessarily replacements for each other.
How to Choose the Right Alternative
- For an identical swap: Mylanta or Gelusil. Same ingredients, same mechanism, same speed of relief.
- For portable, occasional relief: Tums or generic calcium carbonate chewables. Fast-acting and easy to keep in a bag or desk drawer.
- For longer-lasting prevention: An H2 blocker like famotidine, taken before symptoms start.
- For frequent, recurring heartburn: A PPI like omeprazole, taken daily for a 14-day course.
Important Cautions With Any Antacid
Maalox and its direct equivalents (Mylanta, Gelusil, generics) should not be used for more than two weeks at the maximum dose without medical guidance. The standard limit is 16 teaspoons in a 24-hour period.
Aluminum and magnesium-based antacids can interfere with the absorption of other medications. Thyroid medications, certain antibiotics, and iron supplements are particularly affected. If you take prescription drugs on a regular schedule, separate your antacid dose by at least two hours before or after your other medications.
People with kidney disease should avoid magnesium-containing antacids like Maalox, Mylanta, and Rolaids entirely. The kidneys normally clear excess magnesium from the blood, and when they can’t do that efficiently, magnesium levels can build to dangerous concentrations. Calcium carbonate antacids or acid reducers are typically safer options for people in this situation, though the choice should be made with a provider who knows your kidney function.