Aspirin

Low-dose aspirin (usually 75mg) helps stop blood clots in people with heart disease or after a stroke. Higher doses are a painkiller.

Type of medicine

Antiplatelet medicine and painkiller

Also known as

Acetylsalicylic acid, low-dose aspirin, Nu-Seals

Comes as

tablets, dispersible tablets, gastro-resistant tablets

How you get it

Some forms from shops and pharmacies without a prescription

What it is used for

Low dose, preventing heart attacks and strokes in people who have heart or circulation disease
After a heart attack, stroke, mini-stroke (TIA) or heart surgery
Higher doses, mild to moderate pain, high temperature and inflammation

Read our guides:

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Lowering the risk of pre-eclampsia in pregnancy, on a doctor's or midwife's advice
Preventing some bowel cancers in people with Lynch syndrome, on specialist advice

How it works

Low-dose aspirin stops platelets, tiny cells in the blood, from sticking together. This makes clots less likely to form in arteries. At higher doses it blocks chemicals called prostaglandins that cause pain and inflammation.

Side effects

Like all medicines, Aspirin can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

indigestion or stomach pain
bruising more easily
bleeding for longer after a cut

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

vomiting blood, or black or bloody poo
wheezing or worsening asthma
a severe headache or sudden weakness

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

Never give aspirin to children under 16, except on a doctor's advice, because of the risk of Reye's syndrome.
Low-dose aspirin is no longer recommended for people who do not have heart or circulation disease.
It can make asthma worse in some people.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.