Gaviscon Advance is an over-the-counter liquid suspension designed to treat heartburn and acid reflux by forming a physical barrier on top of your stomach contents. Unlike traditional antacids that work by neutralizing stomach acid, Gaviscon Advance uses a high concentration of sodium alginate (a seaweed-derived compound) to create a gel-like “raft” that sits at the top of the stomach and prevents acid from splashing back into the esophagus. It contains 1,000 mg of sodium alginate per 10 ml dose, making it one of the most alginate-dense reflux treatments available.
How the Alginate Raft Works
When you swallow Gaviscon Advance, the sodium alginate reacts with the acid already in your stomach and forms a thick gel. At the same time, potassium bicarbonate (200 mg per 10 ml dose) reacts with that acid to produce carbon dioxide gas. The gas gets trapped inside the gel, turning it into a buoyant raft that floats on top of your stomach contents, almost like a lid.
This raft does several things at once. It acts as a physical barrier at the junction between your stomach and esophagus, blocking acid from traveling upward. Research published in BMJ Open has also shown that alginate formulations can bind to the lining of the esophagus itself, offering some protection from acid and pepsin (the digestive enzyme responsible for much of the tissue damage in reflux). The alginate may also displace what’s known as the “acid pocket,” a layer of highly acidic fluid that pools on top of food after meals and is a major trigger for post-meal reflux episodes.
How It Differs From Other Gaviscon Products
The name “Advance” matters because not all Gaviscon products are the same. Gaviscon Advance contains 1,000 mg of sodium alginate per dose and is built almost entirely around raft formation. Gaviscon Double Action, by contrast, contains only 500 mg of sodium alginate per dose but adds traditional antacid ingredients like calcium carbonate and sodium bicarbonate to actively neutralize acid. Think of it this way: Advance focuses on blocking reflux physically, while Double Action splits its approach between blocking and neutralizing.
It’s also worth noting that Gaviscon products sold in the United States have a completely different formulation from the UK version. The US versions are aluminum- and magnesium-based antacids that work by neutralizing acid rather than forming an alginate raft. If you’ve seen Gaviscon Advance recommended online for reflux, the product being discussed is almost always the UK formulation.
What It’s Used For
Gaviscon Advance is primarily used for gastroesophageal reflux (GERD) symptoms: heartburn, acid taste in the mouth, and the discomfort of food or acid coming back up. It’s particularly popular among people with laryngopharyngeal reflux (LPR), a type of reflux where acid reaches the throat and voice box, causing symptoms like chronic throat clearing, hoarseness, a feeling of a lump in the throat, and persistent cough. Because LPR often doesn’t respond well to standard acid-suppressing medications, the physical barrier approach of an alginate raft can be especially useful.
Lab studies have shown that Gaviscon Advance preserves the barrier function of esophageal and vocal cord cells when exposed to pepsin and acid, compared with placebo. This is relevant for LPR sufferers because pepsin in the throat, not just acid, is thought to drive much of the damage.
Dosage and Timing
For adults and children 12 and older, the standard dose of the liquid suspension is 10 ml taken up to four times a day. The best time to take it is after meals and at bedtime. Taking it after eating is important because that’s when the acid pocket forms and reflux is most likely to occur. The raft needs stomach acid to form properly, so taking it on a completely empty stomach (hours after eating) is less effective.
For children under 12, dosing should be guided by a doctor.
Drug Interactions and Spacing
Because Gaviscon Advance forms a gel layer in the stomach, it can physically interfere with the absorption of other medications you take around the same time. The general rule is to leave a two-hour gap between Gaviscon Advance and other medicines. This is especially important for antibiotics, thyroid hormones, iron supplements, and certain osteoporosis medications, all of which are sensitive to absorption timing.
Safety During Pregnancy and Breastfeeding
Gaviscon Advance is considered safe during pregnancy, which is notable because heartburn affects a large proportion of pregnant women, particularly in the third trimester. According to the NHS, it can be taken while pregnant as long as you follow the recommended dose. It’s also safe while breastfeeding, with no evidence of effects on the baby. There is no known impact on fertility for either men or women.
Who Should Be Cautious
Each dose contains sodium (from the sodium alginate) and potassium (from the potassium bicarbonate). If you’re on a sodium-restricted diet due to high blood pressure or heart problems, or if you have kidney issues that affect how your body handles potassium, it’s worth checking the specific amounts with a pharmacist before using it regularly. For most people taking it occasionally or for a few weeks, this isn’t a concern, but long-term daily use at maximum doses adds up.