Skip to main content


On this page

  1. About lansoprazole
  2. Key facts
  3. Who can and cannot take lansoprazole
  4. How and when to take lansoprazole
  5. Side effects
  6. How to cope with side effects
  7. Pregnancy and breastfeeding
  8. Cautions with other medicines
  9. Common questions

1. About lansoprazole

Lansoprazole reduces the amount of acid your stomach makes. It's used for indigestion, heartburn and acid reflux and gastroesophageal-reflux-disease (GORD). Lansoprazole is also taken to prevent and treat stomach ulcers.

Sometimes, lansoprazole is taken for a rare illness caused by a tumour in the pancreas or gut called Zollinger-Ellison syndrome.

Lansoprazole is available only on prescription. It comes as capsules, tablets and as a liquid that you swallow (made to order).

2. Key facts

  • It's usual to take lansoprazole once a day in the morning.
  • For severe illness, you can take it twice a day – in the morning and in the evening.
  • Common side effects include headache, diarrhoea and stomach pain. These tend to be mild and go away when you stop taking the medicine.
  • Lansoprazole is called by the brand name Zoton FasTabs.

3. Who can and cannot take lansoprazole

Lansoprazole can be taken by adults. It can also be taken by children when prescribed by a doctor.

Lansoprazole isn't suitable for some people.

To make sure lansoprazole is safe for you, tell your doctor if you:

  • have had an allergic reaction to lansoprazole or any other medicines in the past
  • have liver problems
  • are due to have an endoscopy

If you are having an endoscopy, ask your doctor if you should stop taking lansoprazole a few weeks before your procedure. This is because lansoprazole may hide some of the problems that would usually be spotted during an endoscopy. Lansoprazole is generally not recommended in pregnancy or while breastfeeding.

4. How and when to take lansoprazole

It's usual to take lansoprazole once a day – first thing in the morning.

If you take lansoprazole twice a day, take 1 dose in the morning and 1 dose in the evening.

Lansoprazole works best if you take it 30 minutes before a meal or snack. That's because food slows down lansoprazole getting into your system.


The usual dose to treat:

  • indigestion is 15mg to 30mg a day
  • acid reflux is 15mg to 30mg a day
  • stomach ulcers is 15mg to 30mg a day
  • Zollinger-Ellison syndrome is 60mg a day – this can increase to 120mg a day depending on how well it works for you

Doses are usually lower for children, elderly people and people with liver problems.

Tablets and capsules

Swallow tablets and capsules whole with a glass of water or juice.If you have problems swallowing capsules, you can open lansoprazole capsules and mix the granules inside with a little water or fruit juice, or sprinkle them onto soft food, such as yogurt or apple puree, to help you swallow them.

Lansoprazole also comes as a dispersible tablet that melts in your mouth. Each tablet or capsule contains 15mg or 30mg of lansoprazole.

Liquid lansoprazole

Liquid lansoprazole can be prescribed and made to order for children and people who cannot swallow capsules or tablets. It will come with a syringe or spoon to help you take the right amount. If you don't have a syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not give the right amount.

Will my dose go up or down?

Sometimes your doctor will increase your dose of lansoprazole if it isn't working well enough. Depending on the reason you take lansoprazole, you may take a higher dose to begin with, usually for a month or two. After this, your doctor may recommend that you take a lower dose.

How long will I take it for?

Depending on your illness, you may only need to take it for a few weeks or months. Sometimes you might need to take it for longer, even many years. Some people don't need to take lansoprazole every day and take it only when they have symptoms. Once you feel better (often after a few days or weeks), you can stop taking it. Taking lansoprazole in this way is not suitable for everyone. Discuss with your doctor what is best for you.

What if I forget to take it?

If you usually take it:

  • once a day, take the missed dose as soon as you remember, unless it is within 12 hours of your next dose in which case skip the missed dose
  • twice a day, take the missed dose as soon as you remember, unless it is within 4 hours of your next dose in which case skip the missed dose

Do not take a double dose to make up for a forgotten dose.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to remember your medicine.

What if I take too much?

It is very unlikely that taking 1 or 2 extra doses by accident will cause any problems. However, you should check with your doctor if you have taken too much and have any of these symptoms:

  • flushed skin
  • feeling sweaty
  • a fast heartbeat
  • feeling sleepy
  • blurred vision
  • feeling confused or agitated

5. Side effects

Most people who take lansoprazole do not have any side effects. If you do get a side effect, it is usually mild and will go away when you stop taking lansoprazole.

Common side effects

These common side effects may happen in more than 1 in 100 people.

Talk to your doctor or pharmacist if these side effects bother you or don't go away:

  • headaches
  • feeling sick
  • diarrhoea or being sick (vomiting)
  • stomach pain
  • constipation
  • wind
  • itchy skin rashes
  • feeling dizzy or tired
  • dry mouth or throat

Serious side effects

Serious side effects are rare and happen in less than 1 in 1,000 people.

Call a doctor straight away if you have:

  • joint pain along with a red skin rash, especially in parts of your body exposed to the sun, such as your arms, cheeks and nose – these can be signs of a rare condition called subacute cutaneous lupus erythematosus. This can happen even if you've been taking lansoprazole for a long time
  • stomach pain that seems to be getting worse – this can be a sign of an inflamed liver or pancreas

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to lansoprazole.

Immediate action required: Call 999 or go to A&E now if:
  • you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
  • you're wheezing
  • you get tightness in the chest or throat
  • you have trouble breathing or talking
  • your mouth, face, lips, tongue or throat start swelling

You could be having a serious allergic reaction and may need immediate treatment in hospital.

These are not all the side effects of lansoprazole. For a full list see the leaflet inside your medicines packet.


You can report any suspected side effect using the Yellow Card safety scheme.

Visit Yellow Card for further information.

6. How to cope with side effects

What to do about:

  • headaches – make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller. Headaches should usually go away after the first week of taking lansoprazole. Talk to your doctor if they last longer than a week or are severe.
  • feeling sick – it may help if you don't eat rich or spicy food while you're taking lansoprazole.
  • diarrhoea or being sick (vomiting) – drink plenty of water by having small, frequent sips to avoid dehydration. Signs of dehydration include peeing less than usual or having strong-smelling pee. Do not take any other medicines to treat diarrhoea or vomiting without speaking to a pharmacist or doctor.
  • stomach pain – try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help. If you are in a lot of pain, speak to your pharmacist or doctor.
  • constipationeat more high-fibre foods such as fresh fruit and vegetables and cereals, and drink plenty of water. Try to exercise more regularly, for example, by going for a daily walk or run. If this doesn't help, talk to your pharmacist or doctor.
  • wind – steer clear of foods that cause wind like lentils, peas, beans and onions. It might also help to eat smaller and more frequent meals, eat and drink slowly, and exercise regularly. Some pharmacy remedies, such as simethicone, may help relieve the symptoms of wind.
  • itchy skin rashes – it may help to take an antihistamine which you can buy from a pharmacy. Check with the pharmacist to see what type is suitable for you.
  • feeling dizzy or tired – if lansoprazole makes you feel dizzy or tired, stop what you're doing and sit or lie down until you feel better. Do not drive or use tools or machinery if you're feeling tired. Do not drink alcohol as it will make you feel worse.
  • dry mouth or throat – chew sugar-free gum or sugar-free sweets.

7. Pregnancy and breastfeeding

Lansoprazole is not usually recommended during pregnancy and while breastfeeding.

If you're pregnant, it's always better to try to treat your indigestion without taking a medicine.

Your doctor or midwife will first advise that you try to ease your symptoms by eating smaller meals more often, and avoiding fatty and spicy foods.

They may also suggest that you raise the head of your bed 10 to 20cm by putting something under your bed or mattress, so that your chest and head are above your waist. This helps stop stomach acid travelling up towards your throat.

If lifestyle changes don't work, you may be recommended a medicine to help ease your symptoms.

A medicine called omeprazole, which is similar to lansoprazole, is safe in pregnancy.

Lansoprazole and breastfeeding

Lansoprazole may get into breast milk, but it's not known whether it harms the baby.

Talk to your doctor about the pros and cons of taking this medicine while you're breastfeeding.

A medicine called omeprazole, which is a similar to lansoprazole is safe to take while breastfeeding.

Non-urgent advice: Tell your doctor if you're:

  • trying to get pregnant
  • pregnant
  • breastfeeding

8. Cautions with other medicines

Some medicines and lansoprazole can interfere with each other and make it more likely that you will have side effects.

Tell your doctor if you're taking these medicines before your start lansoprazole treatment:

  • digoxin (a heart medicine)
  • antifungal medicines such as itraconazole, ketoconazole or posaconazole
  • methotrexate (treats psoriasis and rheumatoid arthritis)
  • HIV medicines
  • phenytoin (an anti-epilepsy medicine)
  • rifampicin (an antibiotic)
  • blood thinning medicines, such as clopidogrel
  • fluvoxamine (an antidepressant)

These are not all the medicines that may not mix well with lansoprazole. For a full list see the leaflet inside your medicines packet.

Mixing lansoprazole with herbal remedies and supplements

Do not take St John's wort, the herbal remedy for depression, while you're taking lansoprazole. St John's wort may stop lansoprazole working as well as it should.

Important: Medicine safety

Tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.

9. Common questions

How does lansoprazole work?

Lansoprazole is a type of medicine called a proton pump inhibitor (PPI).

Proton pumps are tiny substances in the lining of the stomach which help it make acid to digest food. Lansoprazole prevents proton pumps from working properly. This reduces the amount of acid the stomach makes.

When will I feel better?

You should start to feel better within 2 to 3 days. However, it may take up to 4 weeks for lansoprazole to work properly so you may still have some acid symptoms during this time.

Can I take painkillers with it?

Yes, it's safe to take painkillers such as paracetamol or ibuprofen at the same time as lansoprazole.

It's best to take ibuprofen with, or just after, a meal so it doesn't upset your stomach.

Are there similar medicines?

There are 4 other medicines that are similar to lansoprazole. They are:

Like lansoprazole, these medicines are proton pump inhibitors. They work in the same way as lansoprazole to reduce acid in your stomach.

They generally work as well as and have similar side effects to lansoprazole. However, they may be given in different doses to lansoprazole.

Sometimes, if lansoprazole does not work or agree with you, your doctor may suggest you try taking another proton pump inhibitor.

Are there other medicines for indigestion?

There are a variety of other pharmacy and prescription medicines for indigestion and heartburn.

Antacids, like calcium carbonate (Tums), sodium bicarbonate, Maalox and Milk of Magnesia, relieve indigestion and heartburn by neutralising the acid in your stomach. They give quick relief that lasts for a few hours. They're ideal for occasional bouts of stomach acid symptoms.

Some antacids, such as Gaviscon, have an extra ingredient called alginic acid. They work by lining your stomach so that juices from it don't splash up into your food pipe. They're especially good for relieving acid reflux.

Antacids are available from pharmacies and supermarkets.

H2 blockers (histamine antagonists) reduce the amount of acid made in your stomach, but they do this in a different way to proton pump inhibitors. They include ranitidine (Zantac), cimetidine (Tagamet), famotidine (Pepcid) and nizatidine (Axid).

In general, proton pump inhibitors like lansoprazole are used first because they are better than H2 blockers at reducing stomach acid.

However, if you do not get on with a proton pump inhibitor (for example, because of side effects), your doctor may prescribe an H2 blocker. You can buy famotidine and ranitidine without a prescription from pharmacies.

Can I take lansoprazole with an antacid?

You can take lansoprazole with an antacid, for example Gaviscon, if you need to but leave a gap of 2 hours between them.

Is it safe to take lansoprazole for a long time?

If you take lansoprazole for more than 3 months, the levels of magnesium in your blood may fall. Low magnesium can make you feel tired, confused, dizzy and cause muscle twitches, shakiness and an irregular heartbeat. If you get any of these symptoms, tell your doctor.

Taking lansoprazole for more than a year may increase your chances of certain side effects, including:

  • bone fractures
  • gut infections
  • vitamin B12 deficiency – symptoms include feeling very tired, a sore and red tongue, mouth ulcers and pins and needles

If you take lansoprazole for longer than 1 year your doctor will regularly check your health to see if you should carry on taking it.

It's not known if lansoprazole works less well the longer you take it. If you feel like lansoprazole isn't working any more, talk to your doctor.

Does taking lansoprazole for a long time cause stomach cancer?

A Hong Kong study published in 2017 suggested that people taking proton pump inhibitors (PPIs) like lansoprazole for at least 3 years have a very small increased chance of developing stomach cancer. For every 10,000 people taking a PPI long term, it was thought an extra 4 people get stomach cancer.

However, the study didn't prove that PPIs were causing stomach cancer and the results may not apply in the UK.

People who take PPIs regularly shouldn't be particularly concerned by this study. However, PPIs, like most medicines, have side effects, so it's best to take them for the shortest time possible. Speak to your doctor or pharmacist if you are concerned.

How do I come off lansoprazole?

Usually, you can stop taking lansoprazole without reducing the dose first. If you've taken lansoprazole for a long time, speak to your doctor before you stop taking it. Stopping the medicine suddenly could make your stomach produce a lot more acid, and make your symptoms return.

Reducing the dose gradually before stopping completely will prevent this happening.

Will it affect my fertility?

There's no clear evidence to suggest that taking lansoprazole will reduce fertility in either men or women.

However, speak to a pharmacist or your doctor about it if you're trying to get pregnant. They may want to review your treatment.

Will it affect my contraception?

Lansoprazole doesn't affect any type of regular contraception including the combined pill. It may reduce the effectiveness of one type of emergency contraception called ellaOne (ulipristal), so a different form of emergency contraceptive may be recommended instead.

Can I drive or ride a bike?

Occasionally, lansoprazole can make you feel dizzy, sleepy, or get blurred vision. If this happens to you, do not drive, cycle or use machinery or tools until you feel better.

Can I drink alcohol?

Yes, you can drink alcohol with lansoprazole. However, drinking alcohol makes your stomach produce more acid than normal. This can irritate your stomach lining and make your symptoms worse.

Can lifestyle changes help?

It may be possible to ease symptoms caused by too much stomach acid by making a few changes to your diet and lifestyle.

  • Maintain a healthy weight by eating healthily.
  • Do not eat foods that can make your symptoms worse, such as rich, spicy and fatty foods, and acidic foods like tomatoes, citrus fruits, salad dressings and fizzy drinks.
  • Cut down on caffeinated drinks, such as tea, coffee and cola, as well as alcohol and smoking.
  • If you have symptoms at night, try not to eat for at least 3 hours before you go to bed.
  • Raise the head of your bed 10 to 20cm so that your chest and head are above your waist.

Page last reviewed: 12 November 2018
Next review due: 12 November 2021