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Acidex Original Sugar Free Oral Suspension Peppermint- 500ml

Acidex Original Sugar Free Oral Suspension Peppermint- 500ml

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  • ✔️ Relieves heartburn and acid reflux after meals
  • ✔️ Forms a protective raft to block stomach acid
  • ✔️ Sugar-free formula suitable for diabetics
  • ✔️ Refreshing peppermint flavour for easy palatability
  • ✔️ 500ml bottle provides extended course of treatment

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What Is Acidex Oral Suspension and How Does It Help Heartburn?

 

Heartburn and acid reflux are incredibly common. In fact, the NHS estimates that around one in five people in the UK experience reflux symptoms regularly. If you've ever felt that burning sensation rising up from your stomach after a meal, you'll know just how uncomfortable it can be. Acidex oral suspension is a well-established, over-the-counter alginate antacid that works to relieve those symptoms quickly and without the need for a prescription. The 500ml peppermint-flavoured, sugar-free formula makes it a practical choice for adults who need reliable, everyday relief. You can find it alongside other digestive remedies in our indigestion collection.

This suspension contains three active ingredients — sodium alginate, sodium bicarbonate, and calcium carbonate — which work together to tackle both the mechanical and chemical causes of acid reflux. It's sugar free, making it suitable for people managing their sugar intake, and the refreshing peppermint flavour makes it far more palatable than many alternatives.

 

How Does Acidex Oral Suspension Work to Relieve Acid Reflux?

 

The mechanism behind Acidex is genuinely clever. Rather than simply neutralising acid throughout the stomach, it targets the specific problem area — the gastro-oesophageal junction — where acid tends to escape upwards.

  • Raft formation: Sodium alginate reacts with stomach acid to form a thick, viscous gel raft that floats on top of the stomach contents, acting as a physical barrier against reflux.
  • Acid neutralisation: Sodium bicarbonate and calcium carbonate neutralise excess gastric acid, reducing the acidity of any fluid that does reach the oesophagus.
  • Symptom relief: Together, these actions reduce the burning sensation, regurgitation, and discomfort associated with heartburn and indigestion.
  • Rapid onset: The raft forms within minutes of taking the suspension, providing relatively fast symptomatic relief after meals.

 

Who Should Use Acidex Oral Suspension?

 

Acidex is suitable for adults and children aged 12 and over who experience occasional or frequent heartburn, acid reflux, or indigestion. It's particularly useful after large meals, spicy food, or when lying down triggers symptoms. People who prefer a liquid formulation over tablets — perhaps due to difficulty swallowing — often find this suspension easier to take.

  • Adults experiencing heartburn or acid reflux after meals
  • People with gastro-oesophageal reflux disease (GORD) seeking symptomatic relief
  • Those who prefer a sugar-free, liquid antacid option
  • Individuals who find tablet antacids inconvenient or difficult to swallow

 

How Does Acidex Compare to Other Antacid Suspensions?

 

Feature Acidex Original Sugar Free Peppermint 500ml Gaviscon Original Liquid (600ml)
Active ingredients Sodium alginate, Sodium bicarbonate, Calcium carbonate Sodium alginate, Sodium bicarbonate, Calcium carbonate
Sugar free Yes No (original formulation)
Flavour Peppermint Peppermint / Aniseed
Volume 500ml 600ml

 

Is Acidex Oral Suspension Suitable for Long-Term Use and How Should It Be Stored?

 

Acidex oral suspension is designed for short-term symptomatic relief. If you find yourself relying on it daily for more than two weeks, it's worth speaking to your GP, as persistent symptoms may indicate an underlying condition such as GORD that warrants further investigation. For those managing occasional flare-ups, it remains a convenient and effective option to keep at home. If you're also managing other digestive concerns, our IBS and cramps collection may have additional products worth exploring.

Store the suspension below 25°C and do not freeze it. Once opened, check the label for any in-use storage guidance. Always keep it out of the reach and sight of children. Do not use after the expiry date printed on the bottle.

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 Original Sugar Free Oral Suspension Peppermint 500ml specifications
Treatment category Antacid / Alginate reflux suppressant
Mechanism of action Forms a gel raft on stomach contents; neutralises excess gastric acid
Effective for Heartburn, acid reflux, indigestion, GORD symptoms
Suitable for Adults and children aged 12 and over
Active ingredients Sodium alginate 250mg/5ml, Sodium bicarbonate 133.5mg/5ml, Calcium carbonate 80mg/5ml
Pack size 500ml
UK classification General Sale List (GSL)
Drug class Alginate antacid
Preparation Oral suspension
Route of administration Oral

Specifications of Acidex Original Sugar Free Oral Suspension Peppermint 500ml

 

What Is Acidex Original Sugar Free Oral Suspension and What Is It Used For?

 

Acidex Original Sugar Free Oral Suspension Peppermint is an alginate-based antacid medicine used to relieve the symptoms of heartburn, acid reflux, and indigestion. It works by forming a protective raft on top of stomach contents to prevent acid from rising into the oesophagus. It is available over the counter without a prescription and is classified as a General Sale List (GSL) medicine in the UK. The NHS describes heartburn as a burning feeling in the chest caused by stomach acid travelling up towards the throat — a condition that affects millions of people across the UK.

 

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

 

Before taking this suspension, read the following carefully. There are certain situations where Acidex may not be appropriate, or where extra caution is needed.

Do not use Acidex if you:

  • Are allergic to any of the active or excipient ingredients
  • Have been told to follow a low-sodium diet (this product contains sodium)
  • Are giving it to a child under 12 years of age without medical advice
  • Have severely impaired kidney function without first consulting your GP

Speak to your pharmacist or GP before use if you:

  • Are pregnant or breastfeeding
  • Have heart failure or high blood pressure
  • Have been diagnosed with hypercalcaemia (high calcium levels)
  • Are taking other medicines regularly

Known drug interactions:

  • Antacids can reduce the absorption of certain antibiotics (e.g. tetracyclines, fluoroquinolones)
  • May affect absorption of iron supplements, bisphosphonates, and some antifungals
  • Leave at least a 2-hour gap between Acidex and any other oral medication

 

How Should You Use Acidex Oral Suspension?

 

Always use this medicine exactly as described on the label or as directed by your pharmacist. Shake the bottle well before each use to ensure the suspension is evenly mixed.

  1. Shake the bottle thoroughly before opening.
  2. Measure the correct dose using the measuring cup or spoon provided.
  3. Take the suspension after meals and at bedtime.
  4. Swallow the suspension directly — do not dilute with water.
  5. Do not take more than 4 doses in any 24-hour period.
Indication Age Group Dose Frequency
Heartburn / acid reflux Adults & children 12+ 10–20ml After meals and at bedtime (max 4 times daily)
Indigestion Adults & 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 Oral Suspension?

 

Like all medicines, Acidex can cause side effects, although not everyone experiences them. Most side effects are mild and resolve on their own. If you experience anything severe or persistent, stop use and speak to your pharmacist or GP.

Common side effects:

  • Bloating or flatulence
  • Nausea
  • Stomach discomfort

Less common side effects:

  • Constipation or diarrhoea
  • Raised calcium levels with prolonged high-dose use (hypercalcaemia)
  • Allergic reactions (rash, itching, swelling) — seek immediate medical attention if these occur

If you're also experiencing digestive discomfort alongside other symptoms, it may be worth exploring our sickness and nausea collection for complementary products.

 

How Should You Store Acidex Oral Suspension?

 

Correct storage helps maintain the effectiveness and safety of this medicine. Follow these guidelines carefully.

  • 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're managing multiple health conditions and looking for a convenient way to order your everyday health products, our vitamins and supplements collection is also worth a browse for general wellness support.

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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 oral suspension online in the UK?

You can buy Acidex Original Sugar Free Oral Suspension Peppermint 500ml directly from Cured Pharmacy for just £6.99, with fast UK delivery. It is available over the counter without a prescription, making it easy to order from home. Browse our full range of digestive remedies in our indigestion collection.

How does Acidex oral suspension work in the body?

Acidex works through a dual mechanism: sodium alginate reacts with stomach acid to form a thick gel raft that floats on top of stomach contents, physically preventing acid from rising into the oesophagus. At the same time, sodium bicarbonate and calcium carbonate neutralise excess gastric acid, reducing the burning sensation associated with heartburn. This combination provides both mechanical and chemical relief from reflux symptoms.

How do I use Acidex oral suspension step by step?

Shake the bottle well before each use to ensure the suspension is evenly mixed. Measure 10–20ml using the measuring cup provided and take the dose after meals and at bedtime. Do not exceed four doses in any 24-hour period, and swallow the suspension directly without diluting it with water.

What is the correct dose of Acidex for adults?

The recommended adult dose is 10–20ml taken after meals and at bedtime, up to a maximum of four times daily. You should always use the measuring cup provided to ensure accuracy. If you are unsure about the right dose for your situation, speak to your pharmacist before use.

When is the best time to take Acidex oral suspension?

Acidex is most effective when taken after meals and at bedtime, as this is when stomach acid production is highest and reflux is most likely to occur. Taking it after eating allows the alginate raft to form on top of the stomach contents before they are fully digested. Bedtime dosing is particularly helpful for people who experience night-time heartburn or regurgitation.

What are the side effects of Acidex oral suspension?

Side effects are uncommon but may include bloating, flatulence, nausea, or mild stomach discomfort. Less commonly, prolonged high-dose use may affect calcium levels in the body. If you experience any allergic reaction — such as rash, swelling, or difficulty breathing — stop use immediately and seek medical attention.

How do I manage side effects of Acidex oral suspension?

Most side effects, such as bloating or mild nausea, are temporary and tend to resolve without treatment. If bloating is bothersome, try taking a slightly smaller dose and see if symptoms improve. For persistent or severe side effects, stop using the product and consult your pharmacist or GP promptly.

Is Acidex oral suspension safe to use during pregnancy?

Alginate-based antacids are generally considered one of the safer options for managing heartburn during pregnancy, and the NHS recommends antacids as a first-line treatment for pregnancy-related reflux. However, because this product contains sodium, you should always consult your GP or midwife before taking it during pregnancy. They can advise on the most appropriate option for your individual circumstances.

Can I take Acidex with other medicines?

Acidex may reduce the absorption of certain medicines if taken at the same time, including some antibiotics, iron supplements, and bisphosphonates. It is recommended to leave at least a 2-hour gap between taking Acidex and any other oral medication. Always inform your pharmacist of all medicines you are taking before starting Acidex.

Who is eligible to use Acidex oral suspension?

Acidex 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 advice. People on sodium-restricted diets or with certain kidney conditions should speak to their GP before use.

What happens if I miss a dose of Acidex?

If you miss a dose, simply take it as soon as you remember — unless it is nearly time for your next dose, in which case skip the missed one. Do not double up doses to compensate. Acidex is taken on an as-needed basis after meals, so missing a single dose is unlikely to cause any problems.

How long can you use Acidex oral suspension for?

Acidex is intended for short-term relief of heartburn and indigestion symptoms. If you find you need to use it every day for more than two weeks, you should see your GP, as persistent symptoms may indicate an underlying condition such as GORD that requires further assessment. Do not use it as a substitute for medical investigation of ongoing digestive problems.

What are the alternatives to Acidex oral suspension?

Common alternatives include Gaviscon Original Liquid, which contains the same active ingredients but is not sugar free, and simple antacid tablets such as those containing calcium carbonate. Proton pump inhibitors (PPIs) like omeprazole are available for more persistent reflux but require a different mechanism and are not suitable for everyone. Speak to your pharmacist to find the most appropriate option for your symptoms.

Is Acidex oral suspension sugar free and suitable for diabetics?

Yes, Acidex Original Sugar Free Oral Suspension is formulated without sugar, making it a more suitable choice for people managing their sugar intake, including those with diabetes. However, if you have diabetes and are unsure about any ingredient in this product, it is always best to check with your pharmacist or GP first. You may also find our diabetes monitoring collection useful for managing your condition.

What are the latest studies on alginate antacids like Acidex?

Alginate-based antacids have been studied extensively and are well-supported by clinical evidence as an effective first-line treatment for mild to moderate gastro-oesophageal reflux. Research published in peer-reviewed journals has confirmed that alginate rafts significantly reduce the frequency and severity of reflux episodes compared to placebo. The NHS and NICE both recognise alginate antacids as appropriate options for managing heartburn and GORD symptoms in primary care.

How Should You Use Acidex Original Sugar Free Oral Suspension?

Always shake the bottle thoroughly before each use to ensure the suspension is evenly mixed and the active ingredients are properly distributed. Use the measuring cup or spoon provided with the pack to measure your dose accurately — do not estimate. Swallow the suspension directly without diluting it with water, as dilution may reduce the effectiveness of the alginate raft.

What Is the Correct Dose of Acidex Oral Suspension?

The dose varies depending on age. Children under 12 should not use this product without specific medical advice. Always follow the dosage instructions on the label and do not exceed the maximum daily dose, as doing so will not improve symptom relief and may increase the risk of side effects.

When Is the Best Time to Use Acidex Oral Suspension?

Acidex is most effective when taken after meals and at bedtime. Taking it after eating allows the alginate to react with stomach acid and form a protective raft before food is fully digested, which is when reflux is most likely to occur. The bedtime dose is particularly important for people who experience night-time heartburn or wake with a sour taste in their mouth, as lying down makes it easier for acid to travel upwards.

Avoid taking Acidex immediately before or at the same time as other oral medicines. A gap of at least two hours is recommended to prevent any interference with the absorption of other drugs.

How Long Can You Use Acidex Oral Suspension For?

Acidex is intended for short-term relief of heartburn, acid reflux, and indigestion. Most people use it on an as-needed basis during flare-ups rather than continuously. If you find that you need to take it every day for more than two weeks, this may be a sign that your symptoms require further medical assessment.

Persistent or worsening symptoms — particularly if accompanied by difficulty swallowing, unexplained weight loss, or vomiting — should always be discussed with your GP promptly, as these may indicate a more serious underlying condition.

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

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

Acidex is generally well tolerated, and most people use it without experiencing any significant side effects. However, as with any medicine, some people may notice mild reactions, particularly when first starting treatment or if taking higher doses.

  • Bloating or a feeling of fullness
  • Flatulence (wind)
  • Mild nausea
  • Stomach discomfort or cramping

These effects are usually temporary and tend to resolve on their own without any specific treatment. If they persist or become bothersome, try reducing your dose slightly and see whether symptoms improve.

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

Less commonly, some people may experience the following, particularly with prolonged or high-dose use. If you notice any of these, speak to your pharmacist or GP.

  • Constipation or diarrhoea
  • Raised blood calcium levels (hypercalcaemia) — symptoms may include excessive thirst, frequent urination, or confusion
  • Raised sodium levels with long-term use — relevant for people on sodium-restricted diets or with heart or kidney conditions

What Are the Serious Side Effects of Acidex Oral Suspension?

Serious side effects are rare but can occur. Stop using Acidex immediately and seek urgent medical attention if you experience any signs of an allergic reaction, including:

  • Skin rash, hives, or itching
  • Swelling of the face, lips, tongue, or throat
  • Difficulty breathing or swallowing
  • Sudden dizziness or feeling faint

Allergic reactions to alginate antacids are uncommon, but they can be serious and require immediate medical assessment.

What Should You Do If You Experience Side Effects?

For mild side effects such as bloating or nausea, reducing your dose or taking the suspension with a small amount of food may help. If side effects are persistent, worsening, or affecting your daily life, stop using the product and consult 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.

Never ignore symptoms that feel unusual or severe. Your pharmacist is always a good first point of contact for advice on managing side effects from over-the-counter medicines.

Can Acidex Oral Suspension Interact With Other Medicines?

Yes. Acidex contains antacid components that can affect the absorption of other medicines taken at the same time. This is particularly relevant for the following drug classes:

  • Tetracycline and fluoroquinolone antibiotics — antacids can significantly reduce their absorption
  • Iron supplements — absorption may be reduced if taken alongside antacids
  • Bisphosphonates (e.g. alendronic acid) — should not be taken with antacids
  • Some antifungal medicines (e.g. itraconazole, ketoconazole)
  • Certain thyroid medicines and HIV medications

To avoid interactions, always leave at least a 2-hour gap between taking Acidex and any other oral medication. If you are taking multiple medicines regularly, speak to your pharmacist before starting Acidex to ensure it is safe for you.

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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