Antacid Side Effects: What You Need to Know Before Taking Them

When you reach for an antacid to calm heartburn, you’re using a antacid, a medication that neutralizes stomach acid to relieve discomfort. Also known as heartburn medication, it works fast—often in minutes—but it’s not harmless. Many people think these are safe because they’re sold over the counter, but even simple drugs can have real effects on your body if used too often or the wrong way.

Most antacids contain one or more of three key ingredients: calcium carbonate, a common base found in Tums and other tablets that also acts as a calcium supplement, magnesium hydroxide, a fast-acting ingredient that can cause loose stools, or aluminum hydroxide, a slower-acting compound that may lead to constipation. These aren’t just chemicals—they’re minerals your body uses in other ways. Take too much calcium carbonate and you risk kidney stones or disrupted mineral balance. Use magnesium-based antacids too often and you might get diarrhea or muscle weakness. Aluminum-based ones can interfere with phosphate levels, especially in people with kidney problems. Even though these side effects sound rare, they happen more often than you think when people pop antacids daily for weeks or months.

Some folks use antacids like candy—after every meal, just in case. But that’s not how they’re meant to work. They’re designed for occasional relief, not long-term management. If you’re relying on them every day, you might be masking something bigger: GERD, a hiatal hernia, or even an ulcer. And while antacids give quick comfort, they don’t fix the root cause. Worse, overuse can make your stomach produce even more acid over time, creating a cycle you didn’t know you were in.

What you’ll find below are real comparisons and breakdowns of medications that contain these ingredients—what they do, what they don’t, and what their hidden costs might be. From calcium carbonate’s role in skin health to how magnesium hydroxide interacts with other drugs, the posts here cut through the noise. You’ll see which antacids link to other conditions, which ones people mistake for harmless, and how to tell if you’re using them the right way—or not at all.