Anti-diarrhoeal
Loperamide
Capsule or tablet
Quick Summary
Loperamide reduces how often you pass stool and makes it firmer.
Short-term diarrhoea
IBS with diarrhoea
Medical Uses
Short-term diarrhoea: In adults without fever or blood.
IBS with diarrhoea: As advised.
How it's taken
Take after each loose stool as directed on the pack, without going over the daily limit.
Your doctor decides the right dose for you and how long to take it.
Your doctor decides the right dose for you. Follow their instructions and the label.
Common Side Effects
Constipation
If too much is taken.
Tummy cramps
Sometimes.
Dizziness
Rarely.
Interactions
Some heart and antifungal medicines
Can increase effects.
Critical Warnings
Blood or fever
Black Box Warning: Don't use if there's blood in the stool or high fever.
Children
Black Box Warning: Not for young children unless a doctor advises.
Overuse
Large amounts can cause dangerous heart rhythm problems.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Loperamide: drug information(opens in a new tab) · MedlinePlus, US National Library of Medicine
- Loperamide: a medicine used to treat diarrhoea(opens in a new tab) · NHS