OTC Heartburn Medications: Antacids, H2 Blockers, and PPIs Explained

Heartburn hits hard - that burning feeling in your chest, the sour taste in your throat, the sleepless nights. If you’ve ever reached for a bottle of Tums, Pepcid, or Prilosec without a prescription, you’ve used an OTC heartburn medication. But not all of them work the same way, and not all are safe for long-term use. Knowing the difference between antacids, H2 blockers, and PPIs isn’t just helpful - it could save you from side effects, wasted money, or worse, hidden health risks.

Antacids: Fast but Short-Lived Relief

Antacids are the OG of heartburn remedies. They’ve been around since the 1800s, and they still work fast. If you just ate spicy food and feel that burn creeping up, an antacid like Tums (calcium carbonate) or Milk of Magnesia (magnesium hydroxide) can neutralize stomach acid in under two minutes. That’s why they’re the top pick for occasional heartburn - the kind that happens once a week or less.

But here’s the catch: their relief lasts only 30 to 60 minutes. That’s why you’ll see people popping Tums every hour after dinner. It’s not that they’re addicted - it’s that antacids don’t stop acid production. They just soak it up like a sponge. Once the acid comes back (and it will), so does the pain.

Some antacids come with side effects you might not expect. Calcium carbonate, the main ingredient in Tums, can cause rebound acid hypersecretion in about 30% of users. That means your stomach goes into overdrive and makes even more acid after the antacid wears off. Magnesium-based antacids can cause diarrhea. Aluminum-based ones can cause constipation. And if you’re on other meds - like antibiotics or thyroid pills - antacids can block their absorption. Always wait at least two hours after taking other medications before using an antacid.

H2 Blockers: Slower Start, Longer Stay

If antacids are a fire extinguisher, H2 blockers are like turning down the gas valve. They don’t neutralize acid - they tell your stomach cells to make less of it. The first one, cimetidine (Tagamet), hit the market in 1976. Today, you’ll find famotidine (Pepcid AC), nizatidine (Axid AR), and cimetidine (Tagamet HB) on store shelves.

H2 blockers take 60 to 180 minutes to kick in, so they’re not great for sudden heartburn. But once they work, they last 8 to 12 hours. That makes them ideal for predictable triggers - like eating pizza before bed, or knowing you’ll have a spicy lunch at work. Taking one 30 to 60 minutes before a meal can prevent heartburn before it starts.

Studies show H2 blockers reduce acid production by 60% to 70%. That’s enough to help if you get heartburn one or two times a week. But here’s the problem: your body gets used to them. After two or three weeks of daily use, their effectiveness drops. A 2021 study in Alimentary Pharmacology & Therapeutics found users needed higher doses just to get the same relief. That’s why they’re not meant for long-term daily use.

They also interact with other drugs. Cimetidine can interfere with blood thinners like warfarin and seizure meds like phenytoin. If you’re on any prescription meds, check with a pharmacist before using H2 blockers regularly.

PPIs: The Heavy Hitters - Use With Caution

Proton pump inhibitors (PPIs) are the strongest OTC heartburn meds you can buy without a prescription. Omeprazole (Prilosec OTC), esomeprazole (Nexium 24HR), and lansoprazole (Prevacid 24HR) work by shutting down the acid pumps in your stomach lining. They don’t just reduce acid - they suppress it by 90% to 98%.

But they’re not fast. You won’t feel relief for 24 to 72 hours. That’s why people give up on them too soon. If you take a PPI on Monday and still feel heartburn on Tuesday, you might think it’s not working. But it’s not supposed to. PPIs need three to five days of daily use to reach full effect. And they only work if you take them 30 to 60 minutes before breakfast - before your stomach turns on its acid pumps.

They’re the go-to for frequent heartburn - two or more days a week. A 2022 JAMA Internal Medicine study found PPIs reduced symptoms by 90% over 14 days, compared to 65% for H2 blockers. That’s why they dominate the market, making up 48% of OTC heartburn sales in 2022.

But here’s the dark side. The FDA has issued multiple safety warnings about long-term PPI use. Taking them for more than 14 days in a row without a doctor’s advice can raise your risk of:

• Clostridium difficile infection (a severe gut infection)
• Low magnesium levels (which can cause muscle spasms, irregular heartbeat)
• Vitamin B12 deficiency (especially after two or more years of use)
• Increased hip fracture risk (35% higher with long-term use)
• Chronic kidney disease (23% higher risk after one year of daily use, per Johns Hopkins 2023 research)

And they’re not foolproof. A 2023 study in the New England Journal of Medicine found 1.2 cases of acute interstitial nephritis (a kidney inflammation) per 1,000 PPI users each year. The FDA also warns they can increase the risk of pneumonia.

Don’t take PPIs with orange juice. The acid in the juice can destroy the enteric coating that lets the pill pass through your stomach intact. That’s why you need to take them with water, not juice.

Who Should Use What? A Simple Guide

It’s not about what’s strongest - it’s about what fits your life.

• Less than once a week? Use an antacid. Chew a Tums when you feel it. No need to overthink it.
• Once or twice a week? Try an H2 blocker like Pepcid AC. Take it 30 to 60 minutes before your known trigger meal. Don’t use it every day for more than two weeks.
• Two or more days a week? Talk to your doctor before using a PPI. If you do, use it for only 14 days straight. Then stop. If heartburn comes back, see a professional. Don’t restart without advice.

Many people combine them. About 68% of frequent heartburn sufferers use antacids on top of PPIs for breakthrough pain. That’s fine - as long as you’re not using the PPI longer than 14 days. A 2023 Curist clinical guideline says this combo works well for people who need immediate relief but also want long-term control.

What No One Tells You

Most people don’t realize that heartburn isn’t always caused by too much acid. Sometimes it’s because the valve between your stomach and esophagus is weak, letting acid splash up. Medications don’t fix that. They just mask the symptom.

Also, lifestyle matters more than you think. Losing 10 pounds can cut heartburn in half. Avoiding late-night meals, alcohol, caffeine, and chocolate helps more than any pill. Elevating your head while sleeping reduces nighttime reflux.

And don’t assume OTC means harmless. The FDA issued 17 warning letters to manufacturers in 2022 and 2023 for inadequate safety labeling on PPIs. Generic versions are cheaper - Curist’s generic Prilosec costs $4.99 vs. $24.99 for the brand - but the labeling is often just as vague.

Consumer Reports found that 37% of people who used OTC heartburn meds for more than six months ended up seeing a doctor because their symptoms didn’t improve - or got worse. That’s a red flag. Heartburn that won’t quit could be GERD, a hiatal hernia, or even a sign of something more serious.

What to Do Next

If you’re using OTC heartburn meds regularly, ask yourself:

• Am I using this for more than 14 days in a row?
• Do I need to take it every day to feel okay?
• Have I tried changing my diet, sleep position, or eating habits?

If you answered yes to the first two, it’s time to talk to a doctor. You don’t need to suffer - but you also don’t need to rely on pills that might be doing more harm than good.

For now, keep it simple: use antacids for rare heartburn, H2 blockers for predictable episodes, and PPIs only for frequent symptoms - and never for more than two weeks straight. Your stomach - and your kidneys - will thank you.