1. About low-dose aspirin
Daily low-dose aspirin is a blood thinning medicine. Aspirin is also known as acetylsalicylic acid.
Low-dose aspirin helps to prevent heart attacks and strokes in people at high risk of them.
Your doctor may suggest that you take a daily low dose if you have had a stroke or a heart attack to help stop you having another one.
Or, if you're at high risk of heart attack - for example, if you have had heart surgery or if you have chest pain caused by heart disease (angina).
Only take daily low-dose aspirin if your doctor recommends it.
Low-dose aspirin comes as tablets. It's available on prescription. You can also buy it from pharmacies, shops and supermarkets.
Children are sometimes treated with low-dose aspirin after heart surgery or to treat a rare illness called Kawasaki disease. Children should only take low-dose aspirin if their doctor prescribes it.
Taking low-dose aspirin to prevent heart attacks and strokes is not the same as taking aspirin as a painkiller. Read our information on aspirin for pain relief.
2. Key facts
3. Who can and can't take low-dose aspirin
Most people aged 16 or over can safely take low-dose aspirin if their doctor recommends it.
Low-dose aspirin isn't suitable for certain people.
It's sometimes called baby aspirin because of the small dose, but it's not safe for children.
Never give aspirin to a child younger than 16, unless their doctor prescribes it.
There's a possible link between aspirin and Reye's syndrome in children.
Reye's syndrome is a very rare illness that can cause serious liver and brain damage.
Never give aspirin to children younger than 16, unless their doctor prescribes it.
To make sure low-dose aspirin is safe for you, tell your doctor if you have:
Check with your doctor that it's safe for you to take low-dose aspirin if you're pregnant, trying to get pregnant, or if you want to breastfeed.
4. How and when to take it
Take low-dose aspirin once a day. Don't take it on an empty stomach. It's best to take it with or just after food. This will make it less likely to upset your stomach.
How much should I take?
Your doctor will discuss what dose is right for you. It's important to take low-dose aspirin exactly as recommended by your doctor.
The usual dose to prevent a heart attack or stroke is 75mg once a day (a regular strength tablet for pain relief is 300mg).
The daily dose may be higher - up to 300mg once a day - especially if you have just had a stroke, heart attack or heart bypass surgery.
Different types of low-dose aspirin tablets
Low-dose aspirin comes as several different types of tablet:
You can buy low-dose enteric coated aspirin and low-dose soluble aspirin from pharmacies, shops and supermarkets.
What if I forget to take it?
If you forget to take a dose of aspirin, take it as soon as you remember. If you don't remember until the following day, skip the missed dose.
Do not take a double dose to make up for a forgotten dose.
If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to remember to take your medicine.
What if I take too much?
Taking 1 or 2 extra tablets by accident is unlikely to be harmful.
The amount of aspirin that can lead to overdose varies from person to person.
Call your doctor straight away if:
You take too much aspirin by accident and experience side effects such as:
If you need to go to a hospital accident and emergency (A&E) department, do not drive yourself - get someone else to drive you or call for an ambulance.
Take the aspirin packet or leaflet inside it, plus any remaining medicine, with you.
5. Side effects
Like all medicines, aspirin can cause side effects, although not everyone gets them.
Common side effects
Common side effects of aspirin happen in more than 1 in 100 people.
Talk to your doctor or pharmacist if the side effects bother you or don't go away:
Serious side effects
It happens rarely, but some people have serious side effects after taking low-dose aspirin.
Call a doctor straight away if you get:
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction to aspirin.
Immediate action required:
Call 999 or go to A&E if:
You could be having a serious allergic reaction and may need immediate treatment in hospital.
These aren't all the side effects of aspirin.
For a full list, see the leaflet inside your medicines packet.
You can report any suspected side effect to the UK safety scheme.
6. How to cope with side effects
What to do about:
7. Pregnancy and breastfeeding
Pregnancy and low-dose aspirin
It's generally safe to take low-dose aspirin during pregnancy, as long as your doctor has said it's OK.
Your doctor may advise you to take low-dose aspirin during pregnancy:
For more information about how low-dose aspirin can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPS) website.
Breastfeeding and low-dose aspirin
Aspirin is not generally recommended while you're breastfeeding.
But your doctor may suggest that you take low-dose aspirin while you're breastfeeding if they think the benefits of the medicine outweigh the possible harm.
Tell your doctor if you're:
8. Cautions with other medicines
Some medicines interfere with the way aspirin works.
Tell your doctor if you're taking these medicines before you start taking aspirin:
Mixing low-dose aspirin with painkillers
It's safe to take paracetamol with low-dose aspirin.
But don't take ibuprofen at the same time as low-dose aspirin without talking to your doctor.
Aspirin and ibuprofen both belong to the same group of medicines called non-steroidal anti-inflammatory drugs (NSAIDs).
If you take them together, it can increase your chances of side effects like stomach irritation.
Mixing low-dose aspirin with herbal remedies or supplements
Aspirin may not mix well with quite a lot of complementary and herbal medicines. Aspirin could change the way they work and increase your chances of side effects.
For safety, speak to your pharmacist or doctor before taking any herbal or alternative remedies with aspirin.
Tell your doctor or pharmacist if you are taking any other medicines, including herbal medicines, vitamins or supplements.