Mylanta is an over-the-counter antacid used to relieve heartburn, acid indigestion, sour stomach, and gas. It works within minutes by neutralizing stomach acid and breaking up gas bubbles, making it a go-to option for quick relief after meals or at bedtime.
What Mylanta Treats
Mylanta is designed for everyday digestive discomfort. Its labeled uses include heartburn, acid indigestion, sour stomach, bloating and pressure from gas, and general upset stomach caused by any of these symptoms. It also covers the aftermath of overindulgence in food and drink.
It is not a treatment for chronic conditions like gastroesophageal reflux disease (GERD) or stomach ulcers on its own, though a doctor may recommend it as part of a broader plan. If your symptoms persist beyond two weeks of regular use, that’s a signal something else may be going on.
How It Works
Mylanta contains two types of active ingredients working on two different problems. The antacid portion, a combination of aluminum hydroxide and magnesium hydroxide, directly neutralizes the hydrochloric acid your stomach produces. This raises the pH in your stomach, which reduces the burning sensation you feel when acid irritates your esophagus or stomach lining.
The second ingredient, simethicone, targets gas. It breaks up small gas bubbles in your digestive tract and merges them into larger ones that are easier for your body to pass. This is what helps with the bloating and pressure that often accompany indigestion. The two antacid compounds are paired intentionally: aluminum tends to cause constipation while magnesium tends to cause diarrhea, so combining them helps balance out those effects.
How Quickly It Works
Mylanta typically provides relief within a few minutes of taking it. This fast onset is one of the main advantages liquid antacids have over acid-reducing pills, which can take 30 minutes to several hours to kick in. The tradeoff is that antacids generally wear off faster than those longer-acting medications, so the relief, while quick, is temporary.
Dosing for Adults and Children
For adults and children 12 and older, the standard dose of Mylanta liquid is 10 to 20 mL (one to two doses using the provided cup), taken between meals, at bedtime, or whenever symptoms strike. The maximum is 60 mL (six doses) in a 24-hour period, and you should not use the maximum dose for more than two weeks straight.
A family-strength version is available for children ages 6 to 11, with a dose of 10 mL and a maximum of 30 mL in 24 hours. Children under 6 should not take Mylanta without a doctor’s guidance. Always shake the bottle well before measuring.
Common Side Effects
Most people tolerate Mylanta well. When side effects do occur, they are typically mild and digestive in nature. Constipation and diarrhea each affect roughly 1 in 100 to 1 in 1,000 users. Abdominal pain has also been reported, though its frequency is not well defined. These effects are usually tied to the aluminum and magnesium components. If you notice persistent diarrhea or constipation, switching to a different antacid formulation may help.
Medications That Don’t Mix Well
Mylanta can interfere with the absorption of a surprisingly long list of medications. Certain antibiotics are especially affected, including common ones prescribed for infections like ciprofloxacin, doxycycline, and tetracycline. Some HIV medications, osteoporosis drugs, and other prescriptions are also impacted. The issue is that the minerals in Mylanta can bind to these drugs in your gut or change the acid level enough to prevent proper absorption.
The general rule is to separate Mylanta from other medications by at least two hours, taking whichever one matters more first. If you’re on any prescription medication, it’s worth checking whether an antacid could reduce its effectiveness.
Who Should Be Cautious
The biggest safety concern with Mylanta involves kidney function. Your kidneys are responsible for clearing magnesium and aluminum from your body. When kidney function is reduced, these minerals can accumulate to dangerous levels. Magnesium buildup can cause muscle weakness, dangerously low blood pressure, and in severe cases, respiratory failure. Aluminum accumulation carries its own risks, including bone weakening and, in rare cases, brain damage. Fatalities have been reported in people with significant kidney impairment.
People with kidney disease, intestinal obstruction, or conditions affecting bone mineral balance should either avoid Mylanta or use it only under direct medical supervision. For everyone else, the two-week limit on maximum dosing exists for good reason: occasional use is generally safe, but prolonged daily use at high doses increases the chance of mineral imbalances even in people with healthy kidneys.
Mylanta vs. Other Heartburn Options
Mylanta fills a specific niche in the heartburn relief landscape. It works faster than H2 blockers (like famotidine) and proton pump inhibitors (like omeprazole), which reduce acid production rather than neutralizing it. Those medications take longer to start working but provide relief that lasts many hours or even all day.
If you get occasional heartburn after a big meal or a spicy dinner, Mylanta’s fast action makes it a practical choice. If you’re reaching for it daily, that pattern suggests you may benefit from a longer-acting medication or an evaluation of what’s causing the recurring symptoms.