Omeprazole - Losec

Gastro-oesophageal reflux disease (GORD), peptic ulcers, H. pylori eradication (with antibiotics), prevention of NSAID-induced ulcers, and Zollinger-Ellison syndrome.

Omeprazole irreversibly blocks the proton pump (H+/K+ ATPase) in the stomach lining - the final step in acid production. This reduces stomach acid output by up to 90%. It takes a few days to reach maximum effect because it needs to accumulate and block enough pumps.

Adults and children with acid-related conditions. Available OTC at 10-20mg for short-term heartburn relief. Prescription doses up to 40mg. Long-term use should be reviewed regularly.

Order online and we review your request. A prescriber checks your consultation form for clinical appropriateness and contacts you if anything else is needed. Once approved, your medication is dispensed and delivered to your door.

Tracked: Tracked delivery, arrives in two working days - Free

When it arrives: Every order is sent tracked. Where this page says in post today, it goes out today. Where it says in post tomorrow, it goes out the next working day. On the rare occasions a medicine is unavailable, we will contact you to talk about timing and alternatives.

We dispense clinically equivalent generic medications where available. Prices shown are for the generic version. If you prefer the branded version, let us know in your order form and we will confirm any price difference.

Omeprazole from £14.99 per pack.

Common: headache, diarrhoea, nausea, abdominal pain, constipation, flatulence. Uncommon: dizziness, rash, dry mouth. Long-term use: increased risk of bone fractures, hypomagnesaemia, vitamin B12 deficiency, Clostridium difficile infection.

Hypersensitivity to the active substance or benzimidazole derivatives. Use with caution in hepatic impairment.

Clopidogrel: omeprazole/esomeprazole reduce its effectiveness - use lansoprazole or pantoprazole instead. Reduces absorption of drugs requiring gastric acid (ketoconazole, itraconazole, atazanavir). Methotrexate: may increase levels.

Omeprazole and lansoprazole: extensive use in pregnancy with no evidence of harm, though use only if necessary. Compatible with breastfeeding.

Take 30 minutes before breakfast for best effect. Swallow whole - don’t chew. Long-term use (years) has been linked to small increases in fracture risk, magnesium deficiency, vitamin B12 deficiency and C. difficile infection. Your doctor should review the need for ongoing PPI use at least annually. Don’t stop suddenly after long-term use - rebound acid hypersecretion can occur.