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Lansoprazole - Brand name: Zoton FasTabs

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 of lansoprazole
  7. Pregnancy and breastfeeding
  8. Cautions with other medicines
  9. Common questions about lansoprazole

1. About lansoprazole

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

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

Lansoprazole is only available on prescription. It comes as capsules and tablets.

2. Key facts

  • You'll usually 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.
  • You should start to feel better in 2 to 3 days, but it may take up to 4 weeks for lansoprazole to fully control your acid symptoms.
  • 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 not usually recommended during pregnancy.

3. Who can and cannot take lansoprazole

Most adults and children can take lansoprazole.

Lansoprazole is not suitable for some people. To make sure it's safe for you, tell your doctor before taking lansoprazole if you:

  • have ever had an allergic reaction to lansoprazole or any other medicines
  • have liver problems
  • are pregnant, trying to get pregnant or breastfeeding
  • are due to have an endoscopy

If you're going to have 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.

4. How and when to take lansoprazole

You'll usually 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 at least 30 minutes before a meal or snack. That's because food stops some lansoprazole getting into your system.

Dosage and strength

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, older people and people with liver problems.

Each tablet or capsule contains 15mg or 30mg of lansoprazole.

How to take it

Swallow the tablets or capsules whole with a drink 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 dispersible tablets that melt in your mouth.

Changes to your dose

Sometimes your doctor will increase your dose of lansoprazole if it's not working well enough.

Depending on the reason you take lansoprazole, you may take a higher dose to begin with, usually for a month or 2.

After this, your doctor may recommend that you take a lower dose.

How long to take it for

Depending on your condition, you may only need to take lansoprazole for a few weeks or months. Sometimes you might need to take it for longer, even many years.

Some people do not 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 for a short time to treat symptoms is not suitable for everyone. Discuss with your doctor what is best for you.

If you forget to take it

If you usually take lansoprazole:

  • 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 and take the next one at the usual time
  • 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 and take the next one at the usual time

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

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 to take your medicine.

If you take too much

It is very unlikely that taking 1 or 2 extra doses of lansoprazole will cause any problems.

If you take an extra dose, you might get some of the common side effects. If this happens or you're concerned, contact your doctor.

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 do not 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 or call 111 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 (this may be less noticeable on brown or black skin) – 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
  • severe or persistent diarrhoea – this can be a sign of an inflamed bowel

Serious allergic reaction

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

Immediate action required: Call 999 now if:
  • your lips, mouth, throat or tongue suddenly become swollen
  • you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
  • your throat feels tight or you're struggling to swallow
  • your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
  • you suddenly become very confused, drowsy or dizzy
  • someone faints and cannot be woken up
  • a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of 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 of lansoprazole

What to do about:

  • headaches – make sure you rest and drink plenty of fluids. It's best not to 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 to not eat rich or spicy food while you're taking lansoprazole.
  • diarrhoea or being sick (vomiting) – drink plenty of water or squash by having small, frequent sips to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea or vomiting without speaking to a pharmacist or doctor. If diarrhoea does not get better, talk to your doctor. If you take contraceptive pills and you're being sick or have severe diarrhoea, your contraception may not protect you from pregnancy. Check the pill packet for advice.
  • 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.
  • constipationget more fibre into your diet such as fresh fruit, 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 does not help, talk to your pharmacist or doctor.
  • wind – try not to eat 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 simeticone, 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, cycle 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 suck sugar-free sweets.

7. Pregnancy and breastfeeding

Lansoprazole and pregnancy

Lansoprazole is not usually recommended if you're pregnant because there is little information about its use during pregnancy. Your doctor may recommend a similar medicine called omeprazole instead as there is more safety information available.

You may wish to treat your symptoms without taking medicine. You can try eating smaller meals more often, and avoiding fatty and spicy foods. Sit up straight when you eat, as this will take the pressure off your stomach.

If you get symptoms at night, you could prop your head and shoulders up when you go to bed. This helps to stop stomach acid coming up while you sleep.

Lansoprazole and breastfeeding

If your doctor or health visitor says your baby is healthy, it's OK to take lansoprazole while you're breastfeeding.

It is not known how much passes into breast milk but it's likely to be a very small amount and your baby will not absorb a lot into their body from the breast milk.

It is unlikely that lansoprazole will cause any side effects in your baby.

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 affect each other and make it more likely that you will have side effects or stop one of the medicines working as well.

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

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.

There's not enough information to say that other complementary medicines and herbal remedies are safe to take with lansoprazole. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.

Important: Medicine safety

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

9. Common questions about lansoprazole

How does lansoprazole work?

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

Proton pumps are enzymes in the lining of your stomach that 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 does not upset your stomach.

Are there similar medicines?

There are 4 other medicines that are similar to lansoprazole:

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 well for you or you get side effects, your doctor may suggest you try taking another proton pump inhibitor.

Are there other medicines for indigestion?

There are other prescription medicines and ones you can buy that treat indigestion and heartburn.


Antacids, like calcium carbonate (Tums), sodium bicarbonate, Maalox and Milk of Magnesia, relieve indigestion and heartburn by reducing the damage of acid in your stomach. They give quick relief that lasts for a few hours. They're ideal for occasional 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 do not splash up into your food pipe. They're especially good for relieving acid reflux.

Antacids are available from pharmacies and supermarkets.

H2 blockers

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 cimetidine (Tagamet), famotidine (Pepcid) and nizatidine.

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

However, if a proton pump inhibitor does not suit you (for example, because of side effects), your doctor may prescribe an H2 blocker.

Can I take lansoprazole with an antacid?

You can take lansoprazole with an antacid (for example Gaviscon) if you need to.

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 and 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 that lansoprazole is not working any more, talk to your doctor.

Does taking lansoprazole for a long time cause stomach cancer?

There is some information to suggest people taking medicines that reduce stomach acid, like proton pump inhibitors (PPIs) such as lansoprazole and H2 blockers, might have a very small increased chance of developing stomach cancer. It could be more likely in people taking them for longer than 3 years.

But studies involving more people need to be done to be sure that PPIs and H2 blockers cause stomach cancer, rather than something else causing it.

PPIs, like most medicines, can have side effects so it's best to take them for the shortest time possible.

And it's important to speak to your doctor if you notice any of these symptoms which can be signs of stomach cancer:

  • having problems swallowing (dysphagia)
  • feeling or being sick
  • feeling full very quickly when eating
  • losing weight without trying to

Speak to your doctor or pharmacist if you're concerned.

How do I stop taking lansoprazole?

Usually, you can stop taking lansoprazole without reducing the dose first. But 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 evidence to suggest that taking lansoprazole will reduce fertility in either men or women.

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

Will it affect my contraception?

Lansoprazole does not affect any type of regular contraception including the combined pill. But 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.

If using lansoprazole makes you sick (vomit) or have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Check the pill packet to find out what to do.

Find out what to do if you're on the pill and you're sick or have diarrhoea

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.

It's an offence to drive a car if your ability to drive safely is affected. It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.

Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking lansoprazole. GOV.UK has more information on the law on drugs and driving.

Can I drink alcohol while taking lansoprazole?

Yes, you can drink alcohol with lansoprazole. But it's best not to drink too much, because 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 reduce stomach acid?

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.
  • Cut down on alcohol.
  • Quit smoking if you can.
  • If you have symptoms at night, try not to eat for at least 3 hours before you go to bed.
  • Prop your head and shoulders up when you go to bed. This can stop stomach acid coming up while you sleep.

Page last reviewed: 15 November 2021
Next review due: 15 November 2024