Lansoprazole is a proton pump inhibitor (PPI) that is commonly used to treat various stomach-related conditions, including heartburn, gastroesophageal reflux disease (GERD), and stomach ulcers
Kieran Isgin Money & Lifestyle writer
13:18, 01 Nov 2025
Lansoprazole is often used to treat many stomach conditions(Image: Getty Images)
Those who have been prescribed lansoprazole could be at risk of numerous side effects, some of which may indicate a serious condition. Lansoprazole is a proton pump inhibitor (PPI), similar to omeprazole, and is commonly used to treat various stomach-related conditions, including heartburn, gastroesophageal reflux disease (GERD), and stomach ulcers.
It eases symptoms of these conditions by reducing the amount of acid produced in the stomach. The medication, which is only available on prescription, typically comes in the form of capsules or tablets, reports the Daily Record.
When prescribed lansoprazole, you’ll usually be advised to take it once or twice daily, often 30 minutes before eating a meal or snack for optimal results. The dosage will vary based on your needs and medical condition.
While lansoprazole can be an effective treatment for various stomach conditions, it also comes with a wide range of side effects. Some of these side effects may even be serious enough that you will need to call a doctor or 111 as they could signify a more serious condition, according to NHS guidance.
Stomach pain can also be a common side effect that affects more than one in 100 people taking lansoprazole. Whilst this pain may be minor in some cases, the NHS warns that if you experience stomach pain that feels like it’s getting worse, then you should call a doctor or dial 111.
It emphasises that such abdominal pain “can be a sign of an inflamed liver or pancreas”. Additionally, if you experience severe or frequent diarrhoea whilst taking the PPI, it could also indicate an inflamed bowel.
It’s crucial to understand that these severe side effects are exceptionally uncommon for individuals taking lansoprazole and typically only impact fewer than one in 1,000 people. If you have concerns about taking lansoprazole or the side effects linked with it, it is usually recommended that you initially consult a pharmacist or your GP for additional guidance.
Whilst these side effects may be severe, they typically won’t necessitate a call to 999. Nevertheless, you may need to call 999 if you encounter any of the following symptoms, some of which could indicate a serious allergic reaction to lansoprazole: A feeling of constriction in the throat.
Additional information regarding Lansoprazole’s side effects, as well as methods you can manage them, can be found on the NHS website.