At a glance

QUICK SUMMARY

01 Type of medicine

Antacids

02 Generic

Yes

03 Active ingredient

Sodium Alginate and Potassium Hydrogen Carbonate

04 Effective within

A few minutes after use

05 Works by

Gaviscon Advance contains double the sodium alginate of Gaviscon Original, making it the strongest in the range. It reacts with stomach acid to form a thick, raft-like layer that sits on top of the stomach contents, preventing acid from rising into the oesophagus. At the same time, antacids like potassium bicarbonate and calcium carbonate neutralize excess acid, providing fast relief. Unlike acid suppressants, it doesn’t affect natural acid production.

06 Side effects

Rarely allergic reactions (symptoms include skin rash, itching, breathing difficulties) Uncommon diarrhoea, nausea and vomiting

Medication details

Description

Gaviscon Advance Liquid

Gaviscon Advance is a reflux treatment for heartburn and indigestion, including acid reflux and the burning that comes with it. It carries double the sodium alginate of the original formula, is suitable for day or night use, and is free from sugar and gluten.

How it works

Alginate comes from seaweed, and on contact with stomach acid it sets into a raft that floats on top of the stomach contents. That raft is a physical barrier: it sits at the junction with the oesophagus and blocks acid from rising, which is why alginates suit reflux specifically rather than general stomach discomfort. The antacid component neutralises acid already present, which is what gives the fast soothing relief.

How to use it

Shake the bottle and take the dose stated on the pack after meals and at bedtime, since that is when reflux is most likely. Do not exceed the daily maximum. Alongside it, smaller evening meals, less alcohol and caffeine, not lying down soon after eating and raising the head of the bed all reduce night time reflux.

Who it is for

It is for adults and children as stated on the pack with heartburn, acid reflux or indigestion, including during pregnancy where alginates are commonly chosen. A pharmacist should be consulted if you are on a sodium restricted diet or have kidney problems.

Safety and when to get advice

See a doctor rather than self treating if you have difficulty or pain on swallowing, food sticking, unexplained weight loss, persistent vomiting, vomit that looks like coffee grounds, black tarry stools, or heartburn that is new over the age of 55 or needs treating most days for more than a couple of weeks. Seek emergency help for chest pain with breathlessness, sweating or pain spreading to the arm or jaw. Our UK pharmacy team can answer questions about this product before you buy.

Common questions

When should I take it?
After meals and at bedtime, since the raft works best sitting on top of a full stomach.

How is it different from an antacid?
An antacid neutralises acid. Gaviscon Advance also forms a raft that physically blocks acid from rising.

Can I use it in pregnancy?
Alginates are commonly used in pregnancy, but check with a pharmacist or midwife first.

Always read the patient information leaflet supplied with the pack before use.

Directions

Shake well before use. Adults and children over 12 years: Take 5–10 ml after meals and at bedtime. Children under 12 years: Use only on medical advice.
Follow the instructions on the label or as directed by a healthcare professional.

Ingredients

Each 10 ml dose of Gaviscon Advance contains the active ingredients sodium alginate (1000 mg) and potassium bicarbonate (200 mg), which work together to form a protective barrier and neutralize excess acid.

It also contains: calcium carbonate, carbomer, methyl (E218) and propyl (E216) parahydroxybenzoates, sodium saccharin, sodium hydroxide, and peppermint flavour.
Gaviscon Advance is free from sugar and gluten, making it suitable for individuals with dietary restrictions.

Side Effects

Like all medications, Gaviscon Advance may cause side effects, though they are generally mild and uncommon. Some users may experience bloating, nausea, or an unpleasant taste in the mouth. In rare cases, allergic reactions such as skin rash or difficulty breathing may occur. If any severe or persistent side effects develop, medical advice should be sought immediately.

Warnings

Before using Gaviscon Advance, there are a few precautions to keep in mind. It is not recommended for individuals with severe kidney problems or those on a low-sodium diet, as it contains sodium. Pregnant and breastfeeding women can generally use Gaviscon Advance, but it is best to consult a doctor before doing so. If you are taking other medications, such as those for heart conditions or infections, speak with your pharmacist to ensure there are no potential interactions. For long-term or frequent acid reflux symptoms, professional medical advice is recommended to rule out any underlying conditions.

Medically reviewed and published

  • This page was medically reviewed by Dr Sohaib Imtiaz, Clinical Lead on Apr 11, 2026, 12:00 pm

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FAQs

Please read our FAQs page to find out more.

How quickly does Gaviscon Advance start working?

Gaviscon Advance begins to provide relief almost immediately after taking it. The protective barrier forms within minutes, helping to soothe the burning sensation and prevent further acid reflux. Its effects can last for up to four hours, offering extended comfort and relief.

Can I take Gaviscon Advance with other medications?

While Gaviscon Advance is generally safe, it can interfere with the absorption of certain medications, such as antibiotics or thyroid medications. To avoid this, it is recommended to take Gaviscon Advance at least two hours before or after other medications. If you are unsure, consulting a doctor or pharmacist is always the best approach.

Is Gaviscon Advance safe for daily use?

Gaviscon Advance can be used as needed for symptom relief. However, if you find yourself relying on it frequently for long periods, it is important to speak with a healthcare professional. Persistent acid reflux may indicate an underlying issue that requires further evaluation and management.

Can I take Gaviscon Advance during pregnancy?

Many pregnant women experience acid reflux due to hormonal changes and pressure on the stomach. Gaviscon Advance is considered safe for use during pregnancy, but it is always advisable to check with a doctor or midwife before starting any medication.

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