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Acidex Advance Oral Suspension Aniseed- 500ml

Acidex Advance Oral Suspension Aniseed- 500ml

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  • ✔️ Forms a protective alginate raft to block acid reflux
  • ✔️ Neutralises excess stomach acid with dual-action formula
  • ✔️ Relieves heartburn, indigestion, and acid reflux symptoms
  • ✔️ Pleasant aniseed flavour suitable for adults and children 12+
  • ✔️ Large 500ml bottle provides extended supply at home

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What Is Acidex Advance Oral Suspension and How Does It Relieve Heartburn?

 

If you've ever felt that uncomfortable burning sensation rising up from your stomach after a meal, you'll know how disruptive heartburn can be. Acidex advance oral suspension is an alginate-based antacid liquid designed to provide fast, effective relief from heartburn, acid reflux, and indigestion. Available in a pleasant aniseed flavour, this 500ml bottle is a practical choice for anyone who needs reliable symptom control at home. You can browse our full range of indigestion treatments if you'd like to compare your options.

Heartburn occurs when stomach acid travels back up into the oesophagus, causing irritation and that familiar burning feeling. According to the NHS, it is a very common condition that most people experience at some point. Acidex Advance is formulated to tackle this at the source, using a combination of sodium alginate, sodium bicarbonate, and calcium carbonate to create a physical and chemical barrier against acid reflux.

 

How Does Acidex Advance Oral Suspension Work?

 

The mechanism behind Acidex Advance is straightforward but clever. Rather than simply masking symptoms, it works in two complementary ways:

  • Raft formation: Sodium alginate reacts with stomach acid to form a thick, gel-like raft that floats on top of the stomach contents. This raft acts as a physical barrier, preventing acid from refluxing back into the oesophagus.
  • Acid neutralisation: Sodium bicarbonate and calcium carbonate directly neutralise excess stomach acid, helping to reduce the acidity of the stomach contents beneath the raft.
  • Symptom relief: Together, these actions reduce the burning sensation, discomfort, and regurgitation associated with acid reflux and indigestion.

This dual-action approach means Acidex Advance targets both the cause and the symptoms of reflux, rather than relying on acid suppression alone. It begins working quickly after ingestion, making it particularly useful when taken after meals or at bedtime — two of the most common times for reflux symptoms to flare up.

 

Who Should Use Acidex Advance Oral Suspension?

 

Acidex Advance is suitable for a wide range of people experiencing common digestive complaints. It is particularly well-suited to those who prefer a liquid formulation over tablets, or who find swallowing tablets difficult. It is appropriate for:

  • Adults and children aged 12 and over suffering from heartburn or acid reflux
  • People experiencing indigestion after meals
  • Pregnant women experiencing heartburn (always consult your midwife or GP first)
  • Those who prefer an alginate-based approach rather than proton pump inhibitors or H2 blockers

It is not recommended for children under 12 years of age without medical supervision. If your symptoms are severe, persistent, or accompanied by difficulty swallowing, unexplained weight loss, or vomiting blood, you should seek medical advice promptly rather than self-treating.

 

How Does Acidex Advance Compare to Other Antacid Suspensions?

 

Feature Acidex Advance Oral Suspension Gaviscon Advance Liquid
Active ingredients Sodium alginate, Sodium bicarbonate, Calcium carbonate Sodium alginate, Potassium bicarbonate
Mechanism Raft formation + acid neutralisation Raft formation only
Flavour Aniseed Peppermint or aniseed
Pack size 500ml 150ml or 500ml
Sodium content Moderate — check if on sodium-restricted diet Lower sodium formulation available

 

Is Acidex Advance Oral Suspension Suitable for Long-Term Use?

 

Acidex advance oral suspension is intended for short-term symptomatic relief. If you find yourself relying on it regularly for more than two weeks, it is worth speaking to your GP, as persistent reflux may require further investigation or a different treatment approach. The NHS advises that ongoing heartburn should be assessed to rule out underlying conditions such as gastro-oesophageal reflux disease (GORD). If you are also managing other digestive concerns, our IBS and cramps collection may offer additional support options.

Store the suspension below 25°C and do not freeze. Always shake the bottle well before each use and keep it out of reach of children. Check the expiry date before use and discard any unused suspension after the recommended period stated on the label.

This product is a medicine. Speak to your doctor or pharmacist before using if you have an underlying medical condition or are taking other medicines.

Acidex Advance Oral Suspension Aniseed 500ml specifications
Treatment category Antacid / Alginate reflux suppressant
Mechanism of action Alginate raft formation and acid neutralisation
Effective for Heartburn, acid reflux, indigestion
Suitable for Adults and children aged 12 and over
Active ingredients Sodium alginate 500mg/5ml, Sodium bicarbonate 267mg/5ml, Calcium carbonate 160mg/5ml
Pack size 500ml
UK classification General Sale List (GSL)
Drug class Alginate antacid
Preparation Oral suspension
Route of administration Oral

Specifications of Acidex Advance Oral Suspension Aniseed 500ml

 

What Is Acidex Advance Oral Suspension and What Is It Used For?

 

Acidex Advance Oral Suspension is an over-the-counter medicine used to relieve the symptoms of heartburn, acid reflux, and indigestion. It contains three active ingredients — sodium alginate, sodium bicarbonate, and calcium carbonate — which work together to neutralise stomach acid and form a protective raft over stomach contents. It is available without a prescription and is classified as a General Sale List (GSL) medicine in the UK. The aniseed flavour makes it a palatable option for those who dislike the taste of some other antacid liquids.

The NHS describes heartburn as a burning feeling in the chest caused by stomach acid travelling up towards the throat. Acidex Advance is specifically designed to address this by reducing the likelihood of acid reaching the oesophagus. It is not a cure for the underlying cause of reflux, but it provides meaningful symptomatic relief for most people when used as directed.

 

What Do You Need to Know Before Using Acidex Advance Oral Suspension?

 

Before taking Acidex Advance, it is important to check whether it is appropriate for you. Do not use this product if any of the following apply:

  • You are allergic to sodium alginate, sodium bicarbonate, calcium carbonate, or any other ingredient in the suspension
  • You have been told to follow a low-sodium or sodium-restricted diet (this product contains sodium)
  • You have severely impaired kidney function
  • You are under 12 years of age (unless directed by a doctor)
  • You have hypercalcaemia (high blood calcium levels)

Speak to your pharmacist or GP before use if you are pregnant, breastfeeding, or have any other medical condition. Regarding drug interactions, Acidex Advance may affect the absorption of other medicines if taken at the same time. Known interactions to be aware of include:

  • Tetracycline antibiotics — absorption may be reduced
  • Iron supplements — absorption may be impaired
  • Some antifungal medicines (e.g. ketoconazole) — absorption may be affected
  • Thyroid medicines — separate doses by at least 2 hours

As a general rule, take Acidex Advance at least 2 hours apart from any other oral medicines.

 

How Should You Use Acidex Advance Oral Suspension?

 

Always use this medicine exactly as described in the patient information leaflet or as directed by your pharmacist. Follow these steps each time you take a dose:

  1. Shake the bottle well before use
  2. Measure the correct dose using the measuring cup provided
  3. Take the suspension after meals and at bedtime
  4. Do not lie down immediately after taking the dose
  5. Do not exceed 4 doses in any 24-hour period
Indication Age Group Dose Frequency
Heartburn / acid reflux Adults and children 12+ 10–20ml After meals and at bedtime (max 4 times daily)
Indigestion Adults and children 12+ 10–20ml After meals and at bedtime (max 4 times daily)
Children under 12 Under 12 years Not recommended Seek medical advice

 

What Are the Possible Side Effects of Acidex Advance Oral Suspension?

 

Like all medicines, Acidex Advance can cause side effects, although not everyone experiences them. Most people tolerate it well. If you are also managing other digestive symptoms, you might find our sickness and nausea collection helpful for additional support.

Common side effects (may affect up to 1 in 10 people):

  • Bloating or flatulence
  • Nausea
  • Constipation or diarrhoea

Less common side effects (may affect fewer than 1 in 100 people):

  • Stomach cramps
  • Belching
  • Hypercalcaemia (raised blood calcium) with prolonged high-dose use
  • Allergic reactions such as skin rash or itching — stop use immediately and seek medical advice if this occurs

If you notice any serious or unexpected symptoms, stop taking the suspension and contact your GP or pharmacist promptly.

 

How Should You Store Acidex Advance Oral Suspension?

 

Correct storage helps maintain the quality and effectiveness of the suspension. Follow these guidelines:

  • Store below 25°C in a cool, dry place
  • Do not freeze the suspension
  • Keep the bottle tightly closed when not in use
  • Keep out of the sight and reach of children
  • Do not use after the expiry date printed on the label
  • Do not dispose of medicines via wastewater or household waste — return unused medicine to your pharmacist

If you are looking for further digestive health support alongside your antacid, our constipation collection includes a range of products that may complement your digestive care routine.

Written and reviewed by our qualified team

Your safety and success are our highest priorities. Our medical team rigorously evaluates every product and piece of advice we provide, ensuring you receive only the most effective, science-backed solutions available.

Frequently Asked Questions

Where can I buy Acidex Advance Oral Suspension online in the UK?

You can buy Acidex Advance Oral Suspension Aniseed 500ml directly from Cured Pharmacy, a GPhC-registered UK online pharmacy, for just £8.79. It is available without a prescription as an over-the-counter medicine. Simply add it to your basket and it will be dispatched to your door.

How does Acidex Advance Oral Suspension work in the body?

Acidex Advance works by using sodium alginate, which reacts with stomach acid to form a thick gel raft that floats on top of stomach contents. This raft physically prevents acid from refluxing back up into the oesophagus. Sodium bicarbonate and calcium carbonate also neutralise excess stomach acid directly, providing dual-action relief.

How do I use Acidex Advance Oral Suspension step by step?

Shake the bottle well before each use, then measure 10–20ml using the measuring cup provided. Take the dose after meals and at bedtime, and avoid lying down immediately afterwards. Do not take more than four doses in any 24-hour period.

What is the correct dose of Acidex Advance Oral Suspension for adults?

The recommended adult dose is 10–20ml taken after meals and at bedtime, up to a maximum of four times daily. This means the maximum daily dose is 80ml. Always use the measuring cup provided to ensure accuracy.

When is the best time to take Acidex Advance Oral Suspension?

The best times to take Acidex Advance are after meals and at bedtime, as these are the periods when acid reflux and heartburn are most likely to occur. Taking it after eating allows the alginate raft to form over the stomach contents when they are at their most acidic. Bedtime dosing is particularly helpful for those who experience night-time reflux symptoms.

What are the side effects of Acidex Advance Oral Suspension?

Most people tolerate Acidex Advance well, but some may experience bloating, flatulence, nausea, or changes in bowel habit. Less commonly, stomach cramps or belching may occur. If you notice any allergic reaction such as a rash or swelling, stop use immediately and seek medical advice.

Who is eligible to use Acidex Advance Oral Suspension?

Acidex Advance is suitable for adults and young people aged 12 and over who experience heartburn, acid reflux, or indigestion. It is not recommended for children under 12 without medical supervision. Pregnant women should consult their midwife or GP before use, even though alginate antacids are generally considered safe in pregnancy.

Can I take Acidex Advance Oral Suspension during pregnancy?

Alginate-based antacids like Acidex Advance are often recommended by healthcare professionals for heartburn during pregnancy, as they are not absorbed into the bloodstream. However, you should always speak to your midwife or GP before taking any medicine during pregnancy. They can confirm whether this product is appropriate for your individual circumstances.

What happens if I miss a dose of Acidex Advance Oral Suspension?

If you miss a dose, simply take it as soon as you remember — unless it is nearly time for your next scheduled dose. In that case, skip the missed dose and continue as normal. Never take a double dose to make up for a missed one, as this could increase the risk of side effects.

Can Acidex Advance Oral Suspension interact with other medicines?

Yes, Acidex Advance can affect the absorption of certain medicines if taken at the same time. These include tetracycline antibiotics, iron supplements, some antifungal medicines, and thyroid medications. To avoid interactions, take Acidex Advance at least 2 hours before or after any other oral medicines, and always inform your pharmacist of everything you are taking.

How long can you use Acidex Advance Oral Suspension for?

Acidex Advance is intended for short-term symptomatic relief. If you find you need to use it regularly for more than two weeks, you should speak to your GP, as persistent heartburn or reflux may indicate an underlying condition such as GORD that requires further assessment. Long-term self-treatment without medical review is not recommended.

What are alternatives to Acidex Advance Oral Suspension?

Common alternatives include Gaviscon Advance Liquid, Peptac Liquid, and other alginate-based antacid suspensions available over the counter. For broader digestive health support, you can explore our indigestion treatments collection. Your pharmacist can help you choose the most suitable option based on your symptoms and medical history.

Is Acidex Advance Oral Suspension suitable for people on a low-sodium diet?

Acidex Advance contains sodium, so it may not be suitable for people who have been advised to follow a low-sodium or sodium-restricted diet — for example, those with certain heart or kidney conditions. If you are on a sodium-restricted diet, speak to your GP or pharmacist before using this product. They may be able to suggest a lower-sodium alternative.

What are the latest studies on alginate antacids like Acidex Advance?

Clinical evidence consistently supports the use of alginate-based antacids for the symptomatic relief of gastro-oesophageal reflux. Studies have shown that alginate rafts are effective at reducing both the frequency and severity of reflux episodes compared to placebo. The NHS and NICE both recognise alginate antacids as a first-line option for managing mild to moderate reflux symptoms.

Can I take Acidex Advance Oral Suspension alongside pain relief medicines?

Some pain relief medicines — particularly non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen — can actually worsen heartburn and acid reflux symptoms. If you are taking pain relief regularly and also experiencing reflux, it is worth discussing this with your pharmacist. You can also explore our pain relief collection for alternatives that may be gentler on the stomach.

How Should You Use Acidex Advance Oral Suspension?

Using Acidex Advance correctly makes a real difference to how well it works. Always shake the bottle thoroughly before each use, as the suspension can settle between doses. Use the measuring cup provided — do not estimate the dose by eye, as accuracy matters with liquid medicines.

What Is the Correct Dose of Acidex Advance Oral Suspension?

The dose varies depending on the severity of your symptoms, but you should never exceed the maximum daily amount. The table below summarises the recommended dosing for this product. Always read the patient information leaflet supplied with the product before use.

When Is the Best Time to Use Acidex Advance Oral Suspension?

Timing your doses correctly is key to getting the most benefit from Acidex Advance. The ideal times are after meals and at bedtime — these are the periods when stomach acid production is highest and reflux is most likely to occur. Taking the suspension after eating means the alginate raft forms over a full stomach, providing a more effective barrier against acid rising into the oesophagus. The bedtime dose is particularly valuable for people who experience symptoms during the night or when lying down.

How Long Can You Use Acidex Advance Oral Suspension For?

Acidex Advance is designed for short-term use to manage occasional or mild symptoms of heartburn, acid reflux, and indigestion. If your symptoms persist for more than two weeks despite regular use, or if they worsen at any point, you should stop self-treating and consult your GP. Persistent reflux symptoms can sometimes indicate an underlying condition such as gastro-oesophageal reflux disease (GORD), which may require a different treatment approach or further investigation. Do not use this product continuously for extended periods without seeking medical advice.

Do not exceed the recommended dose. If in doubt, speak to your pharmacist.

What Are the Most Common Side Effects of Acidex Advance Oral Suspension?

Acidex Advance is generally well tolerated by most people when used as directed. However, as with any medicine, some individuals may experience side effects. The most commonly reported ones relate to the digestive system and are usually mild and short-lived.

  • Bloating or a feeling of fullness
  • Flatulence (wind)
  • Nausea
  • Loose stools or mild diarrhoea
  • Constipation

What Are the Less Common Side Effects of Acidex Advance Oral Suspension?

Less commonly, some people may notice other digestive or systemic effects. These are not experienced by the majority of users but are worth being aware of, particularly if you are taking the suspension regularly or at higher doses.

  • Stomach cramps or abdominal discomfort
  • Belching or increased burping
  • Raised blood calcium levels (hypercalcaemia) with prolonged high-dose use — symptoms may include fatigue, confusion, or muscle weakness
  • Increased thirst or frequent urination in rare cases of electrolyte imbalance

What Are the Serious Side Effects of Acidex Advance Oral Suspension?

Serious side effects are rare but can occur. Stop taking Acidex Advance immediately and seek urgent medical attention if you experience any of the following:

  • Signs of an allergic reaction — including skin rash, itching, swelling of the face, lips, tongue, or throat, or difficulty breathing
  • Severe abdominal pain that does not resolve
  • Vomiting blood or passing black, tarry stools — these may indicate a more serious gastrointestinal condition requiring urgent assessment

What Should You Do If You Experience Side Effects of Acidex Advance Oral Suspension?

If you experience mild side effects such as bloating or nausea, these often resolve on their own without stopping treatment. Try taking the suspension with a small amount of water and avoid lying down immediately after your dose. If side effects are persistent, bothersome, or worsen over time, stop using the product and speak to your pharmacist or GP. You can also report suspected side effects directly to the MHRA via the Yellow Card scheme at yellowcard.mhra.gov.uk.

Can Acidex Advance Oral Suspension Interact With Other Medicines?

Yes. Because Acidex Advance contains calcium carbonate and sodium bicarbonate, it can affect the absorption of certain other medicines taken at the same time. To minimise the risk of interactions, always take Acidex Advance at least 2 hours before or after any other oral medicines. Known interactions include tetracycline antibiotics, iron supplements, some antifungal medicines such as ketoconazole, and thyroid medications. Always inform your pharmacist of all medicines, supplements, and herbal remedies you are currently taking before starting Acidex Advance.

If you are concerned about any side effects, contact your pharmacist or GP immediately.

Patient Information Leaflet

Important - Before taking any medication, it is always important to read the Patient Information Leaflet (PIL)

Written and reviewed by our qualified team

GPhC Number: 2233073
Tarun Kumar

Reviewed by:

Tarun Kumar

Superintendent/ Clinical Lead

📖 Find out more about our team of medical content authors and how we ensure the accuracy of our content with our content guidelines.

Content last updated: 31 Mar 2025

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