Omeprazole switches off the pumps that produce stomach acid. It is the strongest of the everyday heartburn treatments, but it is not a rescue remedy — it takes one to four days to reach full effect, so it is the wrong thing to reach for after a heavy meal.
Omeprazole treats heartburn and acid reflux, indigestion, and gastro-oesophageal reflux disease. It is also used to treat and prevent stomach and duodenal ulcers, to protect the stomach in people taking anti-inflammatories long term, and as part of the treatment for Helicobacter pylori infection alongside antibiotics.
For occasional heartburn, an antacid or alginate works within minutes and is a better fit. Omeprazole is for frequent or persistent symptoms.
Usually once daily, in the morning, at least 30 to 60 minutes before food. Swallow capsules whole with water; do not chew them. If swallowing is difficult, some capsules can be opened and the granules mixed with a little water or juice — ask us before doing this, as it depends on the product.
A pharmacy course for frequent heartburn runs up to 14 days. If symptoms return quickly afterwards, or you find yourself buying it repeatedly, see your GP rather than continuing indefinitely — ongoing acid symptoms deserve a proper look.
Most people tolerate omeprazole well. The commonest effects are headache, nausea, diarrhoea or constipation, wind and stomach pain, and they often settle.
With long-term use there are a few things worth knowing about:
None of these is a reason to stop a medicine you genuinely need — but they are a good reason to have long-term use reviewed rather than repeated on autopilot. We can do that as part of a free medicine review.
Omeprazole affects how some other medicines work. The important ones include clopidogrel (where an alternative acid medicine is usually preferred), methotrexate, some HIV medicines, and medicines that need stomach acid to be absorbed properly such as certain antifungals.
Tell us or your GP what else you take before starting it, including anything bought over the counter.
Do not self-treat, and see your GP, if you have:
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