Lactulose Solution - 300ml

What Is Lactulose Solution and How Does It Help?

Constipation is something most people experience at some point — and it can be genuinely uncomfortable. Lactulose solution is a well-established, over-the-counter osmotic laxative that helps relieve constipation by softening stools and encouraging a natural bowel movement. It has been used safely in the UK for decades and is recommended by the NHS for both adults and children. At just £6.99 for a 300ml bottle, it offers a straightforward, affordable option when your digestive system needs a little help. If you're also dealing with related gut discomfort, you might find our IBS and cramps collection useful alongside this product.

Each 5ml of lactulose solution contains 3.35g of lactulose. It comes as a clear, slightly viscous liquid that can be taken on its own or mixed with water or juice. It is not absorbed into the bloodstream, which means it works locally within the gut — making it suitable for a wide range of patients, including those who need to avoid systemic medicines.

How Does Lactulose Solution Work in the Gut?

Lactulose is an osmotic laxative. Rather than stimulating the bowel muscles directly, it works by drawing water into the large intestine from surrounding tissues. This increases the water content of the stool, making it softer and bulkier — and therefore easier to pass. It typically takes 24 to 48 hours to produce a bowel movement, so don't expect instant results.

• Lactulose passes through the small intestine undigested and reaches the colon intact.
• Colonic bacteria ferment lactulose, producing organic acids that lower the pH of the colon.
• The lower pH and osmotic effect draw water into the bowel lumen.
• Stools become softer and easier to pass without straining.

Who Is Lactulose Solution Suitable For?

Lactulose solution is suitable for a broad range of people. It is commonly used for short-term relief of constipation, but it can also be used longer-term under medical supervision — for example, in patients with chronic constipation or hepatic encephalopathy. It is one of the few laxatives considered appropriate during pregnancy and breastfeeding, though you should always check with your GP or midwife first.

• Adults experiencing occasional or chronic constipation
• Children and infants (dose adjusted by age — seek pharmacist advice)
• Pregnant or breastfeeding women (under medical guidance)
• Elderly patients who need a gentle, non-stimulant laxative

How Does Lactulose Solution Compare to Other Laxatives?

Is Lactulose Solution Safe to Store at Home?

Yes. Lactulose solution should be stored below 25°C, away from direct sunlight, and kept out of the reach of children. Do not refrigerate it, as this can cause the solution to thicken. Once opened, use within the period stated on the label. Check the expiry date before use and do not use the product if the solution appears discoloured or has changed in consistency.

If you're managing constipation alongside haemorrhoids — a common combination — it's worth exploring our haemorrhoids and piles collection for additional relief options.

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.

What Is Lactulose Solution and What Is It Used For?

Lactulose solution is an osmotic laxative used to treat constipation. It works by softening the stool and increasing the frequency of bowel movements. The NHS recommends lactulose as a first-line treatment option for constipation in both adults and children. It is also used under specialist supervision to manage hepatic encephalopathy — a condition where the liver cannot adequately remove toxins from the blood — by reducing ammonia absorption in the gut.

Constipation is defined as passing fewer than three stools per week, or passing stools that are hard, dry, and difficult to pass. It is a very common condition in the UK, affecting people of all ages. Lactulose solution offers a gentle, non-habit-forming approach to restoring normal bowel function.

What Do You Need to Know Before Using Lactulose Solution?

Before taking lactulose solution, make sure it is appropriate for you. There are certain situations where it should not be used, and others where caution is needed.

Do not use lactulose solution if you:

• Have galactosaemia (a rare inherited disorder affecting galactose metabolism)
• Have a known bowel obstruction or suspected intestinal blockage
• Are allergic to lactulose or any of the other ingredients in the solution
• Have been told to follow a galactose-free or lactose-free diet (seek medical advice first)

Use with caution and speak to your pharmacist or GP if you:

• Have diabetes — lactulose contains small amounts of lactose and galactose
• Are taking other laxatives or medicines that affect bowel function
• Have inflammatory bowel disease such as Crohn's disease or ulcerative colitis
• Are pregnant or breastfeeding

Known drug interactions:

• No clinically significant interactions are documented at standard doses
• If you are taking any other medicines regularly, always inform your pharmacist before starting lactulose

How Should You Use Lactulose Solution?

Always follow the dosage instructions on the label or as directed by your pharmacist or GP. Lactulose solution can be taken on its own or diluted in water or fruit juice to improve palatability. It is important to drink plenty of fluids throughout the day while taking this medicine — aim for at least six to eight glasses of water daily.

1. Measure the correct dose using the measuring cup or spoon provided.
2. Take the dose orally — swallow it directly or mix with a cold drink.
3. Take your dose at the same time each day to help establish a routine.
4. Allow 24 to 48 hours for the medicine to take effect before adjusting your dose.
5. Do not exceed the maximum recommended daily dose without medical advice.

Doses may be adjusted based on individual response. For children, always seek pharmacist or GP advice before starting treatment. You can browse our full constipation collection if you're looking for additional products to support bowel health.

What Are the Possible Side Effects of Lactulose Solution?

Like all medicines, lactulose solution can cause side effects, although not everyone experiences them. Most side effects are mild and tend to improve after the first few days of treatment as your body adjusts.

Common side effects:

• Flatulence (wind) — particularly in the first few days
• Abdominal bloating or discomfort
• Nausea, especially if taken in large doses
• Diarrhoea if the dose is too high — reduce the dose if this occurs

Less common side effects:

• Abdominal cramps
• Vomiting
• Electrolyte imbalance with prolonged high-dose use (e.g. low potassium) — more relevant in elderly patients

If you experience severe abdominal pain, persistent vomiting, or no bowel movement after three days of use, stop taking lactulose and contact your GP. For related digestive concerns, our diarrhoea collection may also be helpful if you experience loose stools as a result of adjusting your dose.

How Should You Store Lactulose Solution?

• Store below 25°C in a cool, dry place away from direct sunlight.
• Do not refrigerate — cold temperatures can cause the solution to thicken.
• 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 pharmacy.