Introduction
Antacids are a type of medication that are available over the counter from pharmacies and are used to treat the symptoms of heartburn and acid indigestion.
Heartburn
Heartburn is burning chest pain or discomfort that occurs when stomach acid leaks out of the stomach and into the oesophagus (gullet). The acid irritates the surface of the oesophagus which causes the burning sensation in the chest. The medical term for this is gastro-oesophageal reflux disease (GORD).
How antacids work
Antacids can work in two ways. They can:
- coat the surface of the oesophagus with a protective barrier against stomach acid
- produce a gel on the stomach s surface which helps stop acid leaking up into the oesophagus, preventing the symptoms of heartburn
Antacids work by neutralising any acid that is in your stomach, reducing heartburn symptoms and relieving pain.
Antacids can also be combined with other medicines to help relieve the symptoms of heartburn. A number of different antacid medicines are available which all have different brand names.
See antacid medicines names for more information.
Are antacids effective?
There is evidence to show that antacids are effective in providing short-term relief for heartburn.
However, long-term use is not recommended because there are more effective prescription medications that can be used to treat recurring heartburn, such as proton-pump inhibitors (PPIs). PPIs work by reducing the amount of acid that your stomach produces.
There is a lack of evidence showing that the long-term use of antacids is effective in relieving pain that is associated with heartburn.
Lifestyle changes, such as changes to your diet, can help to reduce the symptoms of heartburn. For more information and advice see heartburn treatment.
Visit your GP if the symptoms of heartburn persist for more than a week or if they quickly return after the effects of the antacids has worn off.
Most antacids are not recommended for children under the age of 12. Read more about who can use antacids.
Reporting side effects
The Yellow Card Scheme allows you to report suspected side effects from any type of medicine that you are taking. It is run by a medicines safety watchdog called the Medicines and Healthcare Products Regulatory Agency (MHRA). See the Yellow Card Scheme website for more information.


