Senokot is a stimulant laxative and is indicated for the short-term relief of occasional constipation. It contains senna, which is extracted from the fruits and leaves of the senna plant. Senokot works by stimulating the muscles in your gut to contract and move stools along the intestine, helping you to go to the toilet.


Senokot comes in tablets and syrup. It is not recommended to be taken for more than 1 week. Laxatives do not affect the number of calories absorbed from food. This means they do not help with weight loss.


With the advent of the National Health Service in 1948, an established London-based manufacturer of over-the-counter medicines, Westminster Laboratories Ltd (so-named because its original premises were close to the Abbey itself), turned its attention to producing an effective and reliable laxative.


The brand, Senokot, was launched in the form of a chocolate-flavoured granule. Tablets were introduced to the range in 1955 and sold in tins (50s, 100s and 1000s sizes). Shortly after this, in 1960 Westminster Laboratories became a member of the Reckitt & Colman group of companies. Syrup was added to the range in 1967.  

Senokot Frequently Asked Questions

Here you can find Senokot's most frequently asked questions. If you can't find the answer to your question, please contact us directly.

Usually acts within 8-12 hours.

Talk to your doctor if you are still constipated after 3 days. They may be able to suggest a different medicine.

It’s not recommended to take Senokot for more than 1 week. Taking senna for longer can lead to diarrhoea. Stop taking it if you get diarrhoea.


It can also cause an electrolyte imbalance, where levels of substances like sodium, potassium and magnesium in your body get too high or too low. A severe electrolyte imbalance can cause serious health problems such as:

  • muscle spasms
  • twitching
  • seizure or fits


Taking senna for many weeks, even months, could also stop your bowel working properly on its own.

There are various types of laxatives. Senokot is a stimulant laxative.


The NICE (national institute for health and care excellence) guidelines recommend a stepped approach, so first trying bulk-forming laxatives and moving along the chain if unsuccessful and constipation symptoms remain.


  • Bulk-forming (like Fybogel)- increases the weight of the stool, which makes you feel you want to go to the toilet. These laxatives take 2 or 3 days to work.
  • Osmotic - draws water into the bowel, making the stool softer and easier to pass. These laxatives take at least 2 days to work.
  • Stimulants (like Senokot) - stimulates the muscles of the gut, making the bowel work harder to move stools along. These laxatives usually take 8-12 hours to work.



Senokot does not affect any type of contraception, including the combined pill and emergency contraception, unless you have severe diarrhoea for more than 24 hours.


If you have severe diarrhoea your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do or contact a healthcare professional for further advice.

18 years old, however Senokot products for +12 years old can be purchased in the pharmacy. Please discuss further with a healthcare professional.

You can eat and drink normally with senna (Senokot).


It might help to eat less of foods such as pastries, puddings, sweets, cheese and cake for a while, as these foods can make constipation worse.


Download the free self-care app today - check symptoms, get advice, track your health