Acid reflux/indigestion or heartburn are terms used interchangeably to describe the burning pain caused by stomach acid.
Get prescription acid reflux treatment such as regular Losec (Omeprazole) or Zantac (Ranitidine) for people with severe or ongoing acid symptoms.

Complete a short consultation before selecting your medication. All our consultations are approved by a UK Medical Doctor.

Summary of available medications

Medication Quantity Price
Losec (Omeprazole) 10mg 28 or 56 capsules From £19.99
Omeprazole 10mg (Generic Losec) 28 or 56 capsules From £9.99
Losec 20mg 28 capsules £24.99
Losec MUPS Orodispersible 20mg 28 tablets £22.99
Omeprazole 20mg 28 capsules £17.99
Omeprazole Orodispersible 20mg 28 tablets £19.99

All medications


Medication Quantity Price
Losec (Omeprazole) 10mg 28 capsules £19.99
Losec (Omeprazole) 10mg 56 capsules £29.99
Omeprazole 10mg (Generic Losec) 28 capsules £9.99
Omeprazole 10mg (Generic Losec) 56 capsules £15.99
Losec 20mg 28 capsules £24.99
Losec MUPS Orodispersible 20mg 28 tablets £22.99
Omeprazole 20mg 28 capsules £17.99
Omeprazole Orodispersible 20mg 28 tablets £19.99

All prices exclude prescription fee

What is Losec?

Losec is a brand of omeprazole which is used to treat a number of conditions including acid reflux, also known as heartburn. Acid reflux is caused by hydrochloric acid from the stomach flowing up through the oesophagus when the muscular valve (the lower oesophageal sphincter) which normally prevents this stops working. The lining of the oesophagus is not protected against this acid in the same way the stomach is, therefore a painful burning sensation is experienced in the chest as a result. Losec capsules treat this condition by reducing the amount of acid produced in the stomach to prevent any excess acid reaching the oesophagus and allowing it to heal. Losec is more effective than Zantac in treating acid reflux.

How long does Losec take to work?

Losec does not work immediately. It will usually start to reduce symptoms of acid reflux from the first day although it can take longer to become fully effective. The best results are experienced after taking Losec for 4-5 days.

How long will Losec subdue the symptoms of acid reflux for?

Each dose of Losec suppresses stomach acid for around 24 hours, compared to 12 hours with Zantac.

What else can I do to prevent acid reflux?

Making a number of lifestyle changes can effectively control and minimise the occurrence of acid reflux. Losing weight if necessary, stopping smoking and making dietary changes such as removing food triggers and eating smaller meals could all reduce the likelihood of suffering from heartburn.


Do not take if you are allergic to omeprazole or any of the other ingredients or have an intolerance to certain sugars. Seek medical advice if you are pregnant or breastfeeding. Do not use if you are taking atazanavir to treat HIV. Prolonged use of Losec is not recommended except on medical advice

Losec contains the active ingredient omeprazole, a proton pump inhibitor, which reduces the amount of acid produced by the stomach.

The starting dose is one capsule daily which can be taken with food or on an empty stomach. This can be doubled to two capsules daily if the lower dose has not been effective in reducing symptoms. Losec should be taken for 4-5 days until the symptoms of acid reflux settle.

Losec Side Effects

Common side effects of Losec include agitation, impotence, nausea, vomiting, abdominal pain, flatulence, diarrhoea, constipation and headache.

Less common Losec side effects include dry mouth, swelling of lower limbs, dizziness, sleep disturbances, fatigue, abnormal sensation (tingling, prickling etc.), joint pain, muscle pain, rash and itchiness.

Other reported Losec side effects include taste disturbances, inflammation of mouth, jaundice (yellowing of the skin), hepatitis (liver inflammation), allergic reactions (including anaphylaxis), fever, depression, hallucinations, confusion, enlargement of male breasts, inflammation of kidneys, blood disorders, visual disturbances, sweating, photosensitivity, hair loss, Stevens-Johnson syndrome (life-threatening skin condition), increased risk of fractures and gastro-intestinal infection.