Senokot Senna - 20 Tablets

Are Senna Tablets for Constipation Right for You?

Constipation is something most people experience at some point — and it can be genuinely uncomfortable. Senokot Senna 20 Tablets offer a well-established, over-the-counter option for short-term relief. Each tablet contains senna, a plant-derived active ingredient that has been used as a laxative for centuries. If you're looking for senna tablets for constipation that work gently overnight, Senokot is one of the most recognised names in the UK. You can browse our full range of constipation treatments if you'd like to compare your options before deciding.

Senokot Senna tablets are classified as a stimulant laxative and are available without a prescription for adults and children aged 12 and over. They're designed for occasional use — not as a long-term solution — and are taken orally, usually at bedtime.

How Do Senokot Senna Tablets Work?

Senna works by stimulating the nerve endings in the wall of the large intestine (colon), encouraging the muscles to contract and push stool towards the rectum. The active compounds responsible are called sennosides — specifically sennoside A and sennoside B — which are converted by gut bacteria into their active form in the colon.

• Sennosides are absorbed minimally in the small intestine and reach the colon largely intact.
• Gut bacteria convert sennosides into rhein anthrone, the compound that stimulates bowel muscle contractions.
• Increased peristalsis (bowel movement) moves stool along more quickly.
• A bowel movement typically occurs within 8 to 12 hours of taking the tablet.

This is why most people take Senokot at bedtime — so it works while they sleep and produces a result the following morning.

Who Should Use Senokot Senna Tablets?

Senokot Senna tablets are suitable for adults and young people aged 12 and over who are experiencing occasional constipation. They're particularly useful when dietary changes and increased fluid intake haven't been enough on their own. That said, they're not appropriate for everyone.

• Adults experiencing occasional, short-term constipation
• People who need a predictable, overnight result
• Those who prefer a plant-derived laxative option
• Individuals who have been advised by a pharmacist that a stimulant laxative is appropriate

They are not suitable for children under 12, people with bowel obstruction, inflammatory bowel conditions such as Crohn's disease or ulcerative colitis, or those with unexplained abdominal pain. Always check with your pharmacist if you're unsure.

How Does Senokot Compare to Other Laxative Types?

Is Senokot Suitable for Long-Term Use and How Should It Be Stored?

Senokot Senna tablets should be stored below 25°C in a dry place, away from direct sunlight and out of the reach of children. Check the expiry date on the packaging before use and do not use the product after that date. If you're managing a digestive condition alongside constipation, you may also find our IBS and cramps collection helpful for broader gut health support.

These tablets are intended for short-term use only — no longer than 7 consecutive days. Prolonged use of stimulant laxatives without medical supervision can lead to electrolyte imbalances and, over time, reduced bowel function. If constipation persists beyond a week, speak to your GP.

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 Senokot Senna and What Is It Used For?

Senokot Senna 20 Tablets contain senna as the active ingredient — specifically standardised to provide 7.5 mg of total sennosides per tablet. Senna is a naturally occurring plant extract derived from the leaves and pods of Cassia senna. It belongs to a class of medicines called stimulant laxatives, which work by directly stimulating the muscles of the bowel to contract.

These tablets are used to relieve occasional constipation in adults and young people aged 12 and over. Constipation is defined by the NHS as passing fewer than three stools per week, or passing stools that are hard, dry, or difficult to pass. Senokot is not intended to treat the underlying cause of constipation — it provides symptomatic relief while you address contributing factors such as diet, hydration, and physical activity.

What Do You Need to Know Before Using Senokot Senna Tablets?

Before taking these tablets, it's important to check whether they are appropriate for you. Do not take Senokot Senna tablets if any of the following apply:

• You have a bowel obstruction or suspected bowel obstruction
• You have severe abdominal pain of unknown cause
• You have inflammatory bowel disease (e.g. Crohn's disease or ulcerative colitis)
• You are allergic to senna or any other ingredient in the tablet
• You are under 12 years of age
• You are pregnant (especially in the first trimester) — seek medical advice first
• You have a condition causing muscle weakness (e.g. myasthenia gravis)

Speak to your pharmacist or GP before use if you are breastfeeding, as small amounts of senna metabolites may pass into breast milk. The following medicines may interact with senna:

• Diuretics (water tablets) — increased risk of electrolyte imbalance
• Corticosteroids — may worsen potassium loss
• Digoxin and other cardiac glycosides — electrolyte disturbances can affect their action
• Other laxatives — avoid combining without pharmacist advice

How Should You Use Senokot Senna Tablets?

Always follow the directions on the packaging or as advised by your pharmacist. Here's how to take Senokot Senna tablets correctly:

1. Take the tablets orally with a full glass of water.
2. Swallow the tablets whole — do not crush or chew them.
3. Take at bedtime for a bowel movement the following morning.
4. Do not take more than the recommended dose in any 24-hour period.
5. Do not use for more than 7 consecutive days without speaking to a doctor.

What Are the Possible Side Effects of Senokot Senna Tablets?

Like all medicines, Senokot Senna tablets can cause side effects, although not everyone experiences them. Knowing what to expect can help you manage them if they occur.

Common side effects:

• Abdominal cramps or discomfort
• Loose stools or diarrhoea (especially if the dose is too high)
• Discolouration of urine (yellow-brown or reddish) — harmless and caused by senna metabolites

Less common side effects:

• Nausea
• Electrolyte imbalance with prolonged use (e.g. low potassium)
• Skin reactions such as rash or itching (rare)
• Melanosis coli — a harmless darkening of the bowel lining seen with long-term use

If you experience severe abdominal pain, blood in your stool, or symptoms of dehydration, stop taking the tablets and seek medical advice promptly. If you're also managing related digestive symptoms, our indigestion range may offer additional support.

How Should You Store Senokot Senna Tablets?

• Store below 25°C in a dry place away from direct heat and sunlight.
• Keep the tablets in their original packaging.
• Store out of the sight and reach of children.
• Do not use after the expiry date printed on the pack.
• Do not dispose of medicines via wastewater or household waste — return unused tablets to your pharmacy.

If you're looking for broader digestive health support alongside constipation relief, you might also find our vitamins and supplements collection useful — particularly fibre supplements that support regular bowel habits long-term.