Antacids are medicines that counteract (neutralise) the acid in your stomach to relieve indigestion and heartburn.
They come as a liquid or chewable tablets and can be bought from pharmacies and shops without a prescription.
Antacids may help if you have:
They can quickly relieve your symptoms for a few hours. But they don't treat the underlying cause and long-term use isn't recommended.
Speak to your doctor if you find you need to take antacids regularly.
Many different types of antacid are available. Some are sold under a brand name and others are named after their main ingredient.
Ingredients to look for include:
Some antacids also contain other medicines, such as an alginate (which coats your gullet with a protective layer) and simeticone (which reduces flatulence).
Check the instructions on the packet or leaflet to see how much antacid to take and how often. This depends on the exact medicine you're taking.
Antacids should be used when you have symptoms or think you will get them soon – for most people, the best time to take them is with or soon after meals, and just before going to bed.
Remember that doses for children may be lower than for adults.
Contact your doctor or pharmacist if you take too much of the medicine and start to feel unwell.
It's best to take antacids with food or soon after eating because this is when you're most likely to get indigestion or heartburn.
The effect of the medicine may also last longer if taken with food.
Antacids can affect how well other medicines work, so don't take other medicines within two to four hours of taking an antacid.
You can drink alcohol while taking antacids, but alcohol can irritate your stomach and make your symptoms worse.
Antacids don't usually have many side effects if they're only taken occasionally and at the recommended dose.
But sometimes they can cause:
These should pass once you stop taking the medicine.
Speak to a pharmacist or your doctor if they don't improve or are troublesome. You may need to switch to another medicine.
Antacids are safe for most people to take, although they aren't suitable for everyone.
Speak to a pharmacist or your doctor for advice first if you:
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.