What aspirin is for
Aspirin is a type of medicine called a non-steroidal anti-inflammatory drug (NSAID).
Aspirin can be:
- taken at a low, regular dose (sometimes called baby aspirin) to prevent blood clots, lower your chance of a heart attack or stroke, and prevent high blood pressure in pregnancy (pre-eclampsia)
- taken at a higher dose, only when you need it, to ease pain
How to take aspirin
Aspirin usually comes as tablets you swallow. There's also a type of tablet you dissolve in water and drink (dispersible tablets).
How much you need to take and for how long depends on why you're taking it.
Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or you have any problems taking it.
If a doctor prescribes aspirin for you, follow the advice they give you about how to take it and how much to take.
How to take aspirin for pain
Aspirin for pain relief usually comes as 300mg tablets.
When taking aspirin for pain:
- take 1 to 3 tablets at a time (ideally with or after food)
- wait at least 4 hours between each dose
- do not take more than 4 doses in a day
- swallow tablets whole with a glass of water – if you're taking dispersible tablets, let the tablet dissolve in a glass of water before swallowing it
Always follow the instructions on the medicine packet.
How to take low-dose aspirin
Low-dose aspirin comes as 75mg tablets.
When taking low-dose aspirin:
- you usually take 1 tablet, once a day
- swallow tablets whole with a glass of water – if you're taking dispersible tablets, let the tablet dissolve in a glass of water before swallowing it
If you're taking low-dose aspirin to prevent a heart attack or stroke, you'll usually need to take it for a long time, sometimes for life.
If you miss a dose of low-dose aspirin
If you forget to take a dose of aspirin, take it as soon you remember, unless it's nearly time for your next dose.
If it's nearly time for your next dose, skip the missed dose and take your next dose at the usual time.
Do not take 2 doses to make up for a forgotten dose.
If you take too much aspirin
Taking an extra dose of aspirin is unlikely to cause problems, but it's important to get medical advice if you take too much as it can sometimes be dangerous.
Urgent advice: Speak to a pharmacist as soon as possible if:
- you've taken more aspirin than it says on the packet, leaflet or prescription
If you're unable to speak to a pharmacist, or you took too much of your medicine on purpose, call NHS 111 for advice.
Find a pharmacyIf you're told to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.
Bring the aspirin packet or leaflet inside it, any remaining medicine, and any other medicines you take.
Side effects of aspirin
Like all medicines, aspirin can cause side effects, but not everyone gets them.
Common side effects
Common side effects of aspirin include:
- indigestion and stomach aches
- bleeding more easily than usual (for example, if you cut yourself it may take longer than usual to stop bleeding)
Non-urgent advice: Speak to a pharmacist or doctor if:
- you have any side effects that bother you or do not go away
They may be able to give you advice about how to reduce any side effects. If you're regularly taking low-dose aspirin, keep taking your medicine unless you're advised to stop.
Find a pharmacySerious side effects
Aspirin can sometimes cause serious side effects, although most of them are rare.
Possible serious side effects of aspirin include:
- stomach ulcers or bleeding inside your stomach – causing symptoms such as tummy pain, pale skin, vomiting blood, having poo that's black, sticky and tar-like
- shortness of breath or wheezing
- allergic reactions (including anaphylaxis) – causing symptoms such as a swollen throat or tongue, a raised, itchy rash or difficulty breathing
Urgent advice: Call NHS 111 if:
- you're taking aspirin and you think you might be having serious side effects
More about side effects
These are not all the side effects of aspirin.
For a full list, see the leaflet that came with your medicine or search for your medicine leaflet on the electronic medicines compendium website.
You can report any side effects you get on the Yellow Card Scheme website
Who can and cannot take aspirin
Most adults and children aged 16 years or over can take aspirin.
Do not give aspirin to children aged 15 years or under because it can cause a serious condition called Reye's syndrome in rare cases.
Aspirin is not suitable for some people. For example, it may not be suitable if:
- you've had an allergic reaction or serious side effect from aspirin, ibuprofen or another non-steroidal anti-inflammatory drug (NSAID)
- you have a stomach ulcer or you've had them before
- you have asthma
- you have heart failure
- you have a liver or kidney condition
- you have problems with blood clotting
Check the packet or leaflet that comes with your medicine to see if it's suitable for you. Speak to a pharmacist or doctor if you're not sure if you can use it.
Breastfeeding and aspirin
If you're breastfeeding, check with your doctor before taking aspirin at a low dose for blood clots. They may recommend it if the benefits outweigh the risks to your baby.
Taking a higher dose of aspirin for pain is not usually recommended while you're breastfeeding because there's a risk it could cause side effects in your baby. Paracetamol is usually the best painkiller to take if you're breastfeeding.
If you are advised to take aspirin while breastfeeding, speak to a healthcare professional or call NHS 111 if you have any concerns about your baby.
Pregnancy and aspirin
Tell your doctor if you're pregnant or get pregnant while taking aspirin at a low dose for blood clots. You can usually keep taking it up to week 20 of pregnancy, and sometimes later, if your doctor recommends it.
Your doctor may recommend that you take low-dose aspirin from 12 weeks of pregnancy to prevent pre-eclampsia.
Taking aspirin at a higher dose for pain relief is not recommended during any stage of pregnancy. Paracetamol is usually the best painkiller to take if you're pregnant.
Find out more about taking aspirin during pregnancy on the Bumps (Best Use of Medicines in Pregnancy) website:
Taking aspirin with other medicines, food and drink
There are some medicines, remedies and supplements that may not mix well with aspirin.
These include:
- anticoagulants (such as warfarin or rivaroxaban)
- some steroid medicines
- some antidepressants
- some medicines to lower blood pressure
- methotrexate, a medicine for rheumatoid arthritis, psoriasis or cancer
- other non-steroidal anti-inflammatory drugs (NSAIDs), such as naproxen or ibuprofen
Before taking aspirin, tell your doctor if you're taking any other medicines, herbal remedies, vitamins or supplements.
Taking aspirin with other painkillers
You can take aspirin at the same time as paracetamol if needed. But if you only need the medicine for pain relief, it's a good idea to try either aspirin or paracetamol on their own first to see if they relieve your pain.
Food, drink and alcohol with aspirin
You can eat and drink normally while taking aspirin, but try to limit the amount of alcohol you drink because alcohol can increase the risk of side effects.
Find out more about your medicine
To find out more about your medicine, you can:
- check the leaflet that comes with it
- search for your medicine leaflet on the electronic medicines compendium website
- speak to a pharmacist or doctor for advice – if you recently started taking it, you can get help with newly prescribed medicines from a pharmacist as part of the New Medicine Service