Gaviscon

Medication alginate antacid combination digestive

Aka: sodium alginate + sodium bicarbonate + calcium carbonate, Gaviscon Double Action

Brands seen in Singapore: Gaviscon, Gaviscon Double Action, Gaviscon Advance, Gaviscon Peppermint, Gascovid

Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.

How to use

What it’s for

Heartburn (acid reflux) and indigestion

When to take

After meals and at bedtime · up to 4 times a day (NHS)

Take with

Tablets are chewed, not swallowed whole; liquid is measured

Pros & cons

Pros

NHS: 'gaviscon is a very safe medicine'
General sale list in SG — all 8 alginate products
NHS: safe to take paracetamol at the SAMe time

Cons

NHS: no longer than 7 days without checking a doctor
A 2-hour gap is needed from many other medicines
Sodium and calcium content matters on a low-salt diet

Sources

HSA Register of Therapeutic Products (open data, data.gov.sg d_767279312753558cbf19d48344577084) — datastore_search API, 5,511 rows · read 2026-08-27
what it says
“GAVISCON LIQUID [SIN09494P] … CALCIUM CARBONATE&&SODIUM ALGINATE&&SODIUM BICARBONATE … General Sale List … GAVISCON DOUBLE ACTION TABLETS … GAVISCON ADVANCE-PEPPERMINT FLAVOUR SUSPENSION … GASCOVID LIQUID … General Sale List”
MOH National Drug Formulary — GAVISCON DOUBLE ACTION TABLETS [SIN14194P] (HSA-registered SG product record, updated 28 July 2026) · read 2026-08-27
what it says
“CALCIUM CARBONATE - 187.5 MG SODIUM ALGINATE - 250 MG SODIUM BICARBONATE - 106.5 MG … TABLET, CHEWABLE … GENERAL SALE LIST … RECKITT BENCKISER (SINGAPORE) PTE LTD … ATC code A02BX13”
NHS — About Gaviscon (reviewed 23 April 2025) · read 2026-08-27
what it says
“Gaviscon can be used to treat heartburn (acid reflux) and indigestion. It works by forming a protective layer on top of the contents of your stomach … You'll usually take Gaviscon after meals and at bedtime … If you buy Gaviscon without a prescription, do not take it for longer than 7 days without checking with a doctor”
NHS — How and when to take Gaviscon (reviewed 23 April 2025) · read 2026-08-27
what it says
“If you are 12 years and over, your dose is: 10 to 20ml after meals and at bedtime, up to 4 times a day; 10ml, four times a day if you're taking Gaviscon Advance; 2 to 4 tablets, up to 4 times a day … If you're taking tablets, chew them and do not swallow them whole. The liquid will come with a plastic spoon to help you measure your dose”
NHS — Who can and cannot take Gaviscon (reviewed 23 April 2025) · read 2026-08-27
what it says
“been advised to eat a low calcium or low salt (low sodium) diet … kidney, liver or heart disease … a rare, inherited illness called phenylketonuria … low levels of phosphate in your blood … Gaviscon should only be given to children under 12 years if it's been prescribed or recommended by a doctor”
NHS — Side effects of Gaviscon (reviewed 23 April 2025) · read 2026-08-27
what it says
“Gaviscon is a very safe medicine. Most people who take it do not have any side effects … It's rare, but the ingredients in some types of Gaviscon may be more likely to make you feel sick or cause vomiting, constipation or diarrhoea”
NHS — Taking Gaviscon with other medicines and herbal supplements (reviewed 23 April 2025) · read 2026-08-27
what it says
“Do not take Gaviscon within 2 hours before or after taking: antihistamines; some antibiotics (quinolones and tetracyclines); iron tablets; medicines to treat fungal infections; beta blockers; penicillamine; steroids; antipsychotic medicines; chloroquine; estramustine; bisphosphonates … levothyroxine … It's safe to take paracetamol at the same time as Gaviscon”

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Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.

In Singapore

Classification
HSA register

general sale

This is the Singapore classification, taken from the HSA register. Dosing stays with the label and your pharmacist or doctor — this page never tells you how much to take.

What the label says

NHS, for people 12 years and over: '10 to 20ml after meals and at bedtime, up to 4 times a day'; '10ml, four times a day if you're taking Gaviscon Advance'; '2 to 4 tablets, up to 4 times a day'. NHS on duration: 'if you buy Gaviscon without a prescription, do not take it for longer than 7 days without checking with a doctor'. NHS on overdose: 'if you take more than your usual dose … it may cause side effects such as wind and bloating … This is unlikely to cause you any harm'. every SG alginate product is general sale list — as directed on the pack or by your pharmacist.

Who should check first

Talk to a doctor or pharmacist before taking this if any of these apply to you.

Advised to eat a low calcium or low salt (low sodium) diet: NHS says
Kidney, liver or heart disease: NHS says check first
Phenylketonuria, or low levels of phosphate in the blood: NHS says check first
Children under 12: NHS: only if prescribed or recommended by a doctor; SG packs are general sale list for adults

Documented interactions

With medicines and supplements

Quinolone and tetracycline antibiotics, iron tablets, antifungals, levothyroxine, bisphosphonates: NHS: do not take gaviscon within 2 hours before or after these — absorption of the other medicine is affected⁷
Antihistamines, beta blockers, steroids, antipsychotics, chloroquine, penicillamine, estramustine: NHS lists these in the SAMe 2-hour separation rule; speak to a doctor or pharmacist before starting any of them⁷
Ibuprofen and aspirin: NHS: paracetamol is safe at the SAMe time, but other painkillers such as ibuprofen or aspirin can make the symptoms worse^7,3

Only combinations someone has written down appear here. A pair that is missing is unrecorded, not cleared.