Sounds like 'lan-so-pra-zol'

Lansoprazole is used to treat problems affecting the stomach and gut, such as indigestion, reflux and ulcers. Find out how to take it safely and possible side effects. Lansoprazole is also called Lanzol Relief®.

Type of medicine Also called
  • Medicine to reduce stomach acid 
  • Belongs to a group of medicines known as proton pump inhibitors
  • Lanzol Relief®

What is lansoprazole?

Lansoprazole reduces the amount of acid produced in your stomach. It belongs to a group of medicines known as proton pump inhibitors (PPIs).

Lansoprazole is used to treat conditions associated with high stomach acid such as indigestion, reflux and ulcers. It can prevent ulcers from forming, or help the healing process where damage has already occurred.

It may be given together with certain antibiotics to get rid of Helicobacter pylori, a bacteria found in the stomach that can cause ulcers. 

In New Zealand lansoprazole is available as capsules.


  • The usual dose of lansoprazole is 30 mg once a day.
  • For some people, 15 mg once a day is enough.
  • Your doctor will advise you how long to take lansoprazole for (usually for 4 to 8 weeks). Some people may need to take it for longer.
  • It is best to take the lowest effective dose, for the shortest possible time.  
  • The pharmacy label on your medicine will tell you how much lansoprazole to take, how often to take it and any special instructions.

How to take lansoprazole

  • Take lansoprazole once a day in the morning on an empty stomach, 30 to 60 minutes before breakfast.
  • Swallow the capsule whole with a glass of water. It won't work properly if crushed or chewed.
  • If you forget to take your dose, take it as soon as you remember. But if it is nearly time for your next dose, just take the next dose at the right time. Don't take double the dose.

Things to consider while you're taking lansoprazole

Avoid long-term use of lansoprazole

If you don’t need it, lansoprazole should not be taken long term, because of the possible side effects. There may be a small increased risk of bone fractures, chest infections, gut infection and nutrient deficiencies such as low magnesium and vitamin B12. If you’ve been taking a PPI for reflux for longer than 4 to 8 weeks, and your symptoms seem to be well managed, it’s a good idea to talk to your healthcare provider about reviewing your medicine. They may recommend reducing your treatment. This could include:

  • reducing your daily dose of lansoprazole
  • taking lansoprazole only when you experience the symptoms of heartburn and reflux (also known as on-demand therapy)
  • stopping treatment completely, as your symptoms may not return.

Read more about PPIs for heartburn and reflux.

Taking other medicines

Lansoprazole may be affected by medicines or herbal supplements, so check with your doctor or pharmacist before starting any new medicines. Don't take indigestion remedies (antacids) 2 hours before or after you take lansoprazole.

Having an endoscopy

Ask your doctor if you should stop taking lansoprazole a few weeks before your endoscopy. It may hide some of the problems that would usually be spotted during the procedure.

Possible side effects 

Like all medicines lansoprazole can cause side effects, although not everyone gets them. Often side effects improve as your body adjusts to the new medicine.

Rebound acid secretion when stopping

When lansoprazole is stopped, a common side effect is rebound acid secretion, where the acid secretion in your stomach increases significantly. This should return to normal within 2 weeks.

Because the symptoms of rebound acid secretion are the same as for reflux (such as indigestion, discomfort and pain in your upper stomach and chest, feeling sick and an acid taste in your mouth), it can form an ongoing loop where stopping lansoprazole treatment creates the need to start it again.

Rather than restarting lansoprazole, your doctor may advise you to use antacids such as Acidex, Mylanta or Gaviscon. These can be effective for treating rebound acid secretion so talk to your doctor or pharmacist if you experience it.

Other side effects

Side effects What should I do?
  • Stomach upset, feeling sick
  • Feeling bloated, gas in your abdomen (tummy), farting
  • Loose stools (mild diarrhoea)
  • Constipation
  • These are quite common when you first start taking lansoprazole.
  • Tell your doctor if these side effects bother you.
  • Signs of low magnesium, such as muscle cramps, weakness, tiredness, feeling irritable and changes in heartbeat
  • If you take lansoprazole for more than 3 months, the levels of magnesium in your blood may fall.
  • Tell your doctor if you get these side effects.
  • Signs of low vitamin B12 such as feeling very tired, a sore and red tongue, mouth ulcers and pins and needles.
  • This is most likely if you take lansoprazole long-term, on an ongoing basis.
  • Tell your doctor if you get these side effects.
  • Severe diarrhoea (loose, watery, frequent stools)  
  • This can be a sign of an inflamed bowel.
  • Tell your doctor immediately.
  • Fever and joint pain along with a red skin rash.
  • Rash on parts of your body exposed to the sun, such as your arms, cheeks and nose.
  • Lansoprazole can cause rare conditions called subacute cutaneous lupus erythematosus and drug-induced photo-sensitivity reactions. They can happen even if you have been taking lansoprazole for a long time.
  • Tell your doctor immediately or phone Healthline 0800 611 116.
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product.

Learn more

Medsafe Consumer Information Sheet: Lanzol Relief 
New Zealand Formulary Patient Information: Lansoprazole


  1. Stopping proton pump inhibitors in older people BPAC, NZ 2019
  2. Proton pump inhibitors: When is enough, enough? BPAC, NZ, 2014
  3. Proton pump inhibitors and the risk of acute kidney injury. BPAC, NZ, 2016
  4. Lansoprazole New Zealand Formulary
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 18 Aug 2022