Indigestion medicine
Peer reviewed by Dr Colin Tidy, MRCGPLast updated by Dr Toni Hazell, MRCGPLast updated 26 Mar 2023
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In this series:AntacidsProton pump inhibitorsH2 blockers
Many people use indigestion medicines, usually just occasionally but sometimes more regularly. The same medicines can be used to treat more serious medical conditions such as stomach ulcers or acid reflux. If you need to use indigestion medicines regularly it's very important to see a doctor to get it checked out in case it is caused by an underlying condition that needs further investigations and treatment.
At a glance
Indigestion (dyspepsia) is pain and other symptoms from your upper gut.
Three main types of medicine treat indigestion: antacids, H2 blockers, and proton pump inhibitors.
These medicines work by reducing stomach acid or neutralising it.
Possible side-effects vary but can include diarrhoea, constipation, or headache.
Lifestyle changes like losing weight or avoiding certain foods can help indigestion.
See a doctor for persistent indigestion, unexplained weight loss, or difficulty swallowing.

Unsure about mixing medicines?
Check for possible interactions between medicines, supplements and foods before taking them together.
In this article:
Video picks for Digestive health medicines
Continue reading below
What is indigestion?
Dyspepsia (indigestion) is used to describe pain and sometimes other symptoms which come from your upper gut (the stomach, oesophagus or duodenum). The symptoms of indigestion often occur soon after eating.
Most people have indigestion from time to time but it doesn't last long and doesn't cause any problems. Some people can have frequent or severe bouts of indigestion and if that is the case, it's very important to see a doctor to get it checked out and receive the right treatment. See also the separate leaflet called Indigestion (Dyspepsia).
When acid from the stomach leaks up into the gullet (oesophagus), the condition is known as acid reflux. This may cause heartburn and other symptoms. See also the separate leaflet called Acid Reflux and Oesophagitis.
What are indigestion medicines?
Back to contentsIndigestion medicines can be used to relieve the symptoms of indigestion such as discomfort in your upper tummy (abdomen) or chest. There are three main types of medicine for indigestion: (see the links for more information about each type of indigestion medicine). These are:
Antacids
Antacids usually contain either aluminium or magnesium compounds. They work by reducing the acidity in your stomach. They are often combined with other substances such as alginates, which form a protective layer that floats on the surface of your stomach contents. This helps prevent acid going back up into your gullet (oesophagus) - the tube that connects your mouth to your stomach - and so protects against acid reflux and oesophagitis.
H2 blockers
These medicines work by reducing the amount of acid made in your stomach. By reducing the acidity in your stomach they can be used to treat indigestion, acid reflux, stomach (gastric) ulcers and duodenal ulcers.
The most commonly used H2 blocker in the UK was ranitidine but it has been discontinued as a precaution because of some impurities found in the medicine. If your doctor feels that you need an H2 blocker, they may prescribe a different one.
Proton pump inhibitors (PPIs)
These medicines also reduce the amount of acid made in your stomach. They are also used to treat indigestion and acid reflux, and stomach and duodenal ulcers. Proton pump inhibitors are very effective at reducing stomach acid and are particularly effective at treating acid reflux and gastro-oesophageal reflux disease (GORD).
Continue reading below
How do indigestion medicines work?
Back to contentsThe exact mechanism of action varies between the different types of medication. Proton pump inhibitors stop an enzyme from working so that stomach cells can't pump acid into the stomach. H2 blockers bind to receptors in the stomach cells which interferes with the production of stomach acid. Antacids neutralise the acid in your stomach by stopping the action of an enzyme which creates acid.
What side-effects can indigestion medicines cause?
Back to contentsIndigestion medicines are usually effective and don't cause any side-effects. The following describes some of the more common side-effects but always read the information provided with the medicine. If you have any doubts or concerns then get advice from your pharmacist, nurse or doctor.
Antacids
Antacids that contain magnesium tend to act as a laxative and may cause diarrhoea. Antacids that contain aluminium have the opposite effect and may cause constipation.
Many antacids contain both aluminium and magnesium compounds so that there is a neutral effect on your bowels. Antacids that contain magnesium carbonate may release carbon dioxide gas in your gut (bowel) and this can cause belching.
H2 blockers
The most common side-effects of H2 blockers can include:
Feeling sick (nausea).
Proton pump inhibitors
The most common side-effects of proton pump inhibitors include:
Stomach upset - for example, feeling sick (nausea), stomach ache, or wind (flatulence); tummy pain, and being sick (vomiting).
Diarrhoea.
Constipation.
Headache.
If you take a proton pump inhibitor for a long time, you are likely to get rebound symptoms of acid reflux when you stop, because your stomach has got used to making more acid as a response to the medicines. This usually only lasts for a few days, up to a few weeks as a maximum and it can be treated with antacids or H2 blockers.
Continue reading below
How to help indigestion without medicine
Back to contentsApart from taking an indigestion medicine, there are many things you can do to help, such as:
Don't smoke.
Reduce or stop drinking alcohol.
Avoid foods that can make indigestion worse, such as fatty foods or spicy foods.
If you have heartburn reflux, it may help if you:
Try to eat smaller meals more frequently rather than larger meals.
Avoid eating for the few hours before you go to bed.
Raise the head of your bed.
When should you see a doctor?
Back to contentsYou should see a doctor if you continue to have indigestion symptoms despite a few weeks of using an indigestion medicine. You should always see a doctor if you have any of the following:
Difficulty swallowing (feeling food getting stuck or feeling a lump in your throat).
Losing weight without dieting.
Having a lot of pain in your stomach (abdomen).
Being sick (vomiting), especially if there is any blood in the vomit.
If you’re over 55 and get frequent bouts of indigestion.
Noticing blood in your poo (stools) when you go to the toilet.
Pregnancy
Back to contentsIndigestion and acid reflux are common in pregnancy. It usually helps to reduce the symptoms if you:
Eat smaller meals more often.
Avoid foods and drinks that might make your indigestion worse.
Try not to eat within a few hours of going to bed.
Patient picks for Digestive health medicines

Treatment and medication
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There are a number of preparations available for treating symptoms around your bottom (anus). They may be creams, ointments or suppositories. They may help with itching or pain or bleeding. Many conditions cause symptoms in this area. The most common are piles (haemorrhoids), an itchy bottom (pruritus ani), a split in the skin around the bottom (anal fissure) and constipation.
by Dr Colin Tidy, MRCGP

Treatment and medication
Proton pump inhibitors
Proton pump inhibitors reduce the amount of acid made by the stomach. They are commonly used to treat acid reflux and ulcers of the stomach and part of the gut called the duodenum. Most people who take a proton pump inhibitor do not develop any side-effects.
by Dr Philippa Vincent, MRCGP

Unsure about mixing medicines?
Check for possible interactions between medicines, supplements and foods before taking them together.
Frequently asked questions
What is the difference between indigestion and acid reflux?
Indigestion, also known as dyspepsia, describes pain and other symptoms coming from your upper gut (stomach, oesophagus, or duodenum). Acid reflux is a specific condition where stomach acid leaks up into the gullet, which can cause heartburn and other symptoms. While related, they are distinct conditions.
Are all indigestion medicines the same in how they stop stomach acid?
No, they work in different ways. Antacids reduce acidity by neutralising existing acid. H2 blockers reduce the amount of acid produced by interfering with receptors in stomach cells. Proton pump inhibitors are even more effective, stopping an enzyme that pumps acid into the stomach cells.
Can taking antacids lead to issues with my bowel movements?
Yes, depending on their composition. Antacids containing magnesium may cause diarrhoea, while those with aluminium can cause constipation. Many antacids combine both to achieve a more neutral effect on bowel function.
Are there any specific side-effects I should be aware of if I take H2 blockers?
Common side-effects of H2 blockers can include constipation, diarrhoea, abdominal pain, feeling sick (nausea), dizziness, and headaches.
I've been taking a proton pump inhibitor for a while and am concerned about stopping. Will my acid reflux come back immediately?
If you have been taking a proton pump inhibitor for a long time, you might experience temporary 'rebound' symptoms of acid reflux when you stop. This happens because your stomach may have gotten used to producing more acid in response to the medication. These symptoms usually only last a few days, up to a few weeks at most, and can be managed with antacids or H2 blockers.
What non-medical approaches can I try to ease my indigestion?
You can try lifestyle changes such as losing weight if you are overweight, stopping smoking, reducing alcohol intake, and avoiding foods known to worsen indigestion like fatty or spicy meals. For heartburn reflux, eating smaller, more frequent meals, avoiding eating close to bedtime, and raising the head of your bed may also help.
Should I be concerned if my indigestion symptoms continue even after self-treating for a couple of weeks?
Yes, you should see a doctor if your indigestion symptoms persist for a few weeks despite using an indigestion medicine. Also, consult a doctor if you experience difficulty swallowing, unexplained weight loss, severe abdominal pain, vomiting (especially with blood), are over 55 with frequent indigestion, or notice blood in your stool.
Further reading and references
- Corsetti M, Fox M; The management of functional dyspepsia in clinical practice: what lessons can be learnt from recent literature? F1000Res. 2017 Sep 28;6:1778. doi: 10.12688/f1000research.12089.1. eCollection 2017.
- Dore MP, Pes GM, Bassotti G, et al; Dyspepsia: When and How to Test for Helicobacter pylori Infection. Gastroenterol Res Pract. 2016;2016:8463614. doi: 10.1155/2016/8463614. Epub 2016 Apr 28.
- Dyspepsia - pregnancy-associated; NICE CKS, July 2022 (UK access only)
- Dyspepsia - proven GORD; NICE CKS, July 2023 (UK access only)
- Dyspepsia - proven functional; NICE CKS, December 2022 (UK access only)
Continue reading below
About the authorView full bio

Dr Colin Tidy, MRCGP
General Practitioner, Medical Author
MBBS, MRCGP, MRCP (Paediatrics), DCH
Dr Colin Tidy is an NHS Doctor, based in Oxfordshire.
About the reviewerView full bio

Dr Colin Tidy, MRCGP
General Practitioner, Medical Author
MBBS, MRCGP, MRCP (Paediatrics), DCH
Dr Colin Tidy is an NHS Doctor, based in Oxfordshire.
Article history
The information on this page is written and peer reviewed by qualified clinicians.
Next review due: 24 Mar 2028
26 Mar 2023 | Latest version
7 Mar 2018 | Originally published
Authored by:
Dr Colin Tidy, MRCGP

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