What is aspirin?

Aspirin is one of a group of drugs called non-steroidal anti-inflammatory drugs (NSAIDs). It's widely used to relieve mild to moderate pain and inflammation.

It's available over the counter in 300 mg tablets and is usually taken in doses of 300–600 mg four times a day after food.

Aspirin is also used in low doses (75 mg daily) to reduce the risk of strokes and heart attacks. This dose doesn't have a pain-relieving effect.

Side-effects and risks

Aspirin can cause stomach-related side-effects at higher doses. Soluble forms reduce this risk to some extent, as do tablets which have a special 'enteric' coating to make sure the drug isn't absorbed into the body until it reaches the small intestine.

However, you shouldn't take aspirin if you have:

  • indigestion
  • heartburn
  • or a history of stomach ulcers.

It can cause bleeding in the digestive system, particularly if:

  • you drink alcohol
  • you take the blood-thinning drug warfarin
  • or you're over 60.

For this reason many doctors will now advise you not to take aspirin for pain relief, but to take a different NSAID or a coxib instead.

You should speak to your doctor if you're thinking of taking fish oil supplements because these can interact with aspirin. However, it's fine to eat oily fish.

In some people, aspirin can make asthma worse or cause an allergic reaction that results in rashes and hives. If you experience any of these side-effects you must stop taking aspirin immediately.

Children and young people under the age of 16 shouldn't take aspirin.

If you're on long-term, low-dose aspirin you must be careful about taking other NSAIDs because this could increase the risk of stomach bleeding. Ask your doctor for advice if you're unsure.

Find out more about the other NSAIDs available.