Maalox typically starts relieving heartburn and indigestion within 5 to 15 minutes of taking a dose. Because its active ingredients work by directly neutralizing stomach acid on contact, relief begins almost as soon as the liquid or chewable tablet reaches your stomach. This makes it one of the faster options for occasional acid-related discomfort.
Why Maalox Works Quickly
Maalox contains two antacid compounds, aluminum hydroxide and magnesium hydroxide, that chemically neutralize stomach acid the moment they make contact with it. Unlike acid-reducing medications that need to be absorbed into your bloodstream before they do anything, antacids like Maalox work locally inside your stomach. That direct, on-contact reaction is what gives you noticeable relief in minutes rather than hours.
Some Maalox formulations also contain an anti-gas ingredient (simethicone) that helps break up gas bubbles in your digestive tract. This targets the bloating and pressure that often accompany heartburn. Simethicone also works physically rather than chemically, so it starts reducing that uncomfortable fullness shortly after you take it.
How Long the Relief Lasts
A single dose of Maalox generally provides relief for about 1 to 3 hours. How long it lasts depends largely on whether you’ve eaten recently. On an empty stomach, the antacid moves through faster and may wear off within an hour. Taken after a meal, when food slows stomach emptying, it can keep working for closer to 3 hours.
This is why dosing instructions typically suggest taking Maalox 20 minutes to 1 hour after meals and again at bedtime. Timing it this way keeps the antacid in your stomach longer, extending the window of relief. You can redose every 3 to 4 hours as needed.
Liquid vs. Chewable Tablets
Liquid Maalox tends to work slightly faster than chewable tablets because the suspension is already in a form that spreads across your stomach lining quickly. With tablets, you need to chew them thoroughly so the active ingredients can dissolve and start neutralizing acid. If you’re looking for the fastest possible relief, the liquid form has a small edge.
That said, the difference is usually only a few minutes. Tablets are more convenient to carry, so the tradeoff is speed versus portability.
Standard Dosing for Adults
For the liquid suspension, the standard adult dose is 2 to 4 teaspoons (10 to 20 mL) up to 4 times a day. The maximum in a 24-hour period is 16 teaspoons (80 mL). Taking more than the recommended amount won’t speed up relief, but it can increase the likelihood of side effects like diarrhea or constipation.
Aluminum hydroxide tends to cause constipation, while magnesium hydroxide tends to cause loose stools. The combination in Maalox is designed so these two effects roughly cancel each other out, but at higher doses, one side effect may win out depending on your individual digestive system.
When Maalox Isn’t the Right Fit
Because antacids only neutralize acid that’s already in your stomach, they’re best suited for occasional, short-term symptoms. If you find yourself reaching for Maalox more than a few times a week, the underlying issue may need a different approach. Frequent acid reflux that doesn’t respond well to antacids often responds better to medications that reduce acid production over a longer period.
People with kidney problems should be cautious with Maalox. The aluminum and magnesium it contains are normally cleared by the kidneys without issue, but impaired kidney function can allow these minerals to build up in the body. If you have reduced kidney function, check with a pharmacist before using Maalox regularly.
Getting the Fastest Relief
A few practical tips can help you get the most out of each dose. Shake liquid Maalox well before measuring it, since the active ingredients can settle at the bottom of the bottle. Take it between meals or shortly after eating rather than on a completely empty stomach if you want longer-lasting effects. And stay upright for at least 15 to 20 minutes after taking it, since lying down can push the antacid out of your stomach before it finishes working.
If your symptoms don’t improve within 15 to 20 minutes of taking Maalox, that’s unusual for simple heartburn or indigestion. Persistent or worsening chest pain, especially with shortness of breath, warrants immediate medical attention regardless of what over-the-counter remedies you’ve tried.