Heartburn: Antacid vs H2 Blocker vs PPI
There are three completely different kinds of heartburn medicine on the shelf, and the most common mistake is reaching for the slowest one during an attack. The right choice depends on one question: is this occasional heartburn happening right now, or heartburn that keeps coming back?
Antacids — for relief in minutes
Calcium carbonate and aluminum/magnesium products neutralize acid that is already in the stomach. They work in 2–5 minutes and last about 30–60 minutes. Nothing else on the shelf is faster.
Use them for occasional, predictable heartburn — a heavy meal, spicy food, late dinner.
Liquid suspensions coat and work slightly faster than tablets. Combination antacid/simethicone products add gas relief. Alginate products (Gaviscon) form a raft on top of stomach contents and are the pick if reflux hits when you lie down.
Watch the ceiling on calcium if you take a lot of chewables, and note that antacids can interfere with the absorption of other medicines — separate them by about two hours.
H2 blockers (famotidine) — for hours of cover
Famotidine reduces how much acid the stomach produces. It works in about 30–60 minutes and lasts up to 12 hours.
Its real strength is prevention: taken 30–60 minutes before a meal you know will cause trouble, it heads off heartburn rather than chasing it.
Ranitidine (Zantac) was withdrawn from the market in 2020 over NDMA contamination. Famotidine is the replacement and is not affected.
Taking an antacid alongside famotidine is reasonable — the antacid covers the first half hour before the famotidine takes effect.
PPIs (omeprazole, esomeprazole, lansoprazole) — for frequent heartburn
PPIs shut down acid production much more completely, but they take 1–4 days to reach full effect. They are the wrong tool for an attack in progress.
They are labeled for heartburn occurring two or more days a week, taken as a 14-day course, up to three courses a year, no more often than every four months. Take the dose 30–60 minutes before the first meal of the day.
If you need more than the labeled courses, that is a conversation with your provider, not a reason to keep buying boxes. Long-term use carries a modest association with B12 deficiency, low magnesium, bone fracture and C. difficile infection.
Omeprazole can interact with clopidogrel and some other medicines — worth a quick check with your pharmacist.
When to stop self-treating and get checked
See a provider promptly for: difficulty or pain swallowing, food sticking, unintentional weight loss, vomiting blood or black tarry stools, persistent vomiting, or heartburn that does not respond to a full labeled course.
Chest pain with shortness of breath, sweating, or pain radiating to the arm or jaw is a 911 call, not heartburn — heart attacks are regularly mistaken for indigestion.
What we stock
- Foster & Thrive Extra Strength Antacid Calcium Carbonate 750 mg Chewables, Assorted Fruit — 96 ct — $4.40. Same strength as Tums Extra Strength at roughly a third less.
- Tums Extra Strength 750 Chewable Tablets, Assorted Berries — 96 ct — $6.84. The name brand, if you prefer it.
- Foster & Thrive Antacid & Antigas Suspension (Alumina, Magnesia, Simethicone) — 12 oz — $5.69. Liquid works fastest, and the simethicone covers gas and bloating too.
- Gaviscon Extra Strength Chewable Tablets, Original — 100 ct — $11.72. Alginate raft — best option for reflux when lying down.
- Good Sense Acid Reducer Famotidine Tablets, 10 mg — 30 ct — $4.48. Take 30–60 minutes before a trigger meal to prevent heartburn.
- Pepcid AC Maximum Strength Tablets, 20 mg — 25 ct — $12.37. Full-strength famotidine, name brand.
- Foster & Thrive Acid Reducer + Antacid Chewable Tablets, Berry — 25 ct — $9.00. Combines both — fast antacid relief plus famotidine cover.
- Foster & Thrive Omeprazole DR Acid Reducer 20 mg — 14 tablets — $10.08. One full 14-day course. Take before breakfast; allow a few days for effect.
- Prilosec OTC Omeprazole 20 mg — 42 tablets — $29.67. Three courses in one box.
- Nexium 24HR Acid Reducer Delayed-Release Capsules — 14 ct — $11.63. Esomeprazole — an alternative if omeprazole has not worked for you.
Frequently asked questions
What is the difference between an antacid, an H2 blocker and a PPI?
An antacid such as calcium carbonate neutralizes acid already in the stomach and works in two to five minutes, lasting about an hour. An H2 blocker such as famotidine reduces acid production, works in 30 to 60 minutes and lasts up to 12 hours, which makes it good for preventing heartburn before a trigger meal. A PPI such as omeprazole shuts acid production down much further but takes one to four days to reach full effect, so it is for frequent heartburn rather than an attack in progress.
What is the fastest thing to take for heartburn right now?
An antacid. Chewable calcium carbonate or a liquid antacid suspension neutralizes stomach acid within a few minutes. A PPI like omeprazole will do nothing for heartburn happening at that moment, because it needs one to four days of daily dosing to take full effect.
How long can I take omeprazole over the counter?
The over-the-counter label is a 14-day course, repeated no more than three times a year and no more often than every four months. If your heartburn keeps returning after a course, see your provider rather than continuing to self-treat — prolonged acid suppression is associated with B12 deficiency, low magnesium, fractures and C. difficile infection.
Is famotidine safe after Zantac was recalled?
Yes. The 2020 withdrawal involved ranitidine, which could form the contaminant NDMA over time. Famotidine is a different molecule, was not part of that recall, and is the standard over-the-counter H2 blocker now.
When should heartburn be checked by a doctor?
Get seen promptly for trouble or pain swallowing, food sticking, unintentional weight loss, vomiting blood or black tarry stools, persistent vomiting, or heartburn that does not respond to a full labeled course of treatment. Chest pain with shortness of breath, sweating or pain spreading to the arm or jaw needs emergency care — heart attacks are often mistaken for indigestion.
This guide is general information, not medical advice. Talk with your pharmacist or provider about your situation.