What it is used for

Preventing strokes after an ischaemic stroke or mini-stroke (TIA)
Preventing heart attacks in people with peripheral arterial disease
After a heart attack or unstable angina, often with aspirin
After having a stent put in a heart artery

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.

Clopidogrel is not commonly used off-label.

How it works

Clopidogrel blocks a receptor on platelets called P2Y12. This stops platelets clumping together and forming clots in arteries.

Side effects

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

Common side effects

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

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:

blood in your pee or poo, or black poo
vomiting or coughing up blood
a severe headache or sudden weakness. Call 999
unexplained bruising with a high temperature and confusion

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

Tell any doctor or dentist you take it.
Some indigestion medicines, such as omeprazole and esomeprazole, can make it work less well. Ask a pharmacist.

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.