Gaviscon vs ENO vs Antacil: Which to Choose?

Quick Answer: Choose by Your Main Symptom

All three manage stomach acid, but their mechanisms — and ideal symptoms — differ clearly. Here is the full picture:

Gaviscon — the Alginate Raft Against Reflux

Gaviscon's strength is managing the reflux itself, not just the acid — alginate forms a floating gel raft that physically seals the top of the stomach. It answers:

• Post-meal heartburn
• Sour regurgitation, bitter taste in the throat
• Night-time reflux — the raft holds acid down while lying back

The formula most common in Thailand is Gaviscon Dual Action 150 ml liquid, combining antacid + raft in one bottle — full guide: Gaviscon: Uses, Dosage & Precautions

ENO — Effervescent Salts for Bloating and Indigestion

ENO is a fruit salt (Sodium Bicarbonate + Citric Acid) that fizzes in water and neutralises acid fastest of the three. It suits:

• Bloating and fullness after a heavy meal
• Sudden indigestion needing quick relief

Limitations: short-lived, no anti-reflux barrier, and high in sodium — not for regular use, especially with hypertension, kidney or heart disease.

Antacil — the Classic Coating Antacid

Antacil is the Aluminium Hydroxide + Magnesium Hydroxide antacid Thai pharmacies have dispensed for decades. It suits:

• Epigastric pain from excess acid
• Stomach irritation after spicy or harsh food

Notes: aluminium salts can cause constipation while magnesium can cause loose stools — the combination balances the two. People with kidney disease should consult first, as mineral clearance slows.

Three Different Mechanisms: Raft vs Fizz vs Coat

Why can't these three fully substitute for each other? They act at different points:

• Gaviscon — acts at the stomach–oesophagus junction: a physical raft stops acid rising to injure the oesophagus — direct anti-reflux action
• ENO — acts on overall acidity: instantly neutralises stomach acid in one shot — for sudden fullness
• Antacil — acts at the stomach lining: neutralises acid while easing mucosal irritation — for acid-gnawing epigastric pain

Seen this way, choosing is easy: chest/throat symptoms → Gaviscon · bloating → ENO · epigastric pain → Antacil

Can You Combine or Alternate Them?

Do not stack them in the same dose — all three contain acid-neutralising salts, so stacking adds no benefit while loading unnecessary minerals (sodium, calcium, aluminium, magnesium).

• Pick one product for the day's main symptom
• You may switch products as symptoms change, but space the doses
• All three need a ~2-hour gap from other medicines, as they equally interfere with absorption

Cautions for Each Product

• Gaviscon: contains sodium and calcium — caution with kidney disease, heart disease, hypertension, high calcium · generally usable in pregnancy but consult a doctor first
• ENO: highest sodium of the three — unsuitable for sodium-restricted people and not for regular use · the fizz may cause belching
• Antacil: caution in kidney disease (aluminium/magnesium accumulation) · may cause constipation or loose stools · prolonged use should be under medical advice

All three: stop and see a doctor for any allergic reaction (rash, swelling, breathing difficulty), and always ask a pharmacist first if you have chronic conditions or regular medicines.

When Antacids Aren't Enough — Think PPI or H2

All three products are relievers. If any of these apply, the root cause needs treating:

• Heartburn more than twice a week for several weeks
• Needing antacids daily for over 2 weeks
• Alarm symptoms: difficulty swallowing, weight loss, vomiting blood, black stools

A doctor may consider a PPI (long-term acid suppression) or an H2 blocker plus lifestyle changes — use these under medical or pharmacist guidance.

📖 Read more: Deep dive into every reflux medicine class — Acid Reflux Medicines — PPI, H2 and Antacids Explained

💡 Read more: Frequent episodes turning chronic? How to treat it for good — Treating Chronic Acid Reflux for Good