Can I take Aspirin and St john's wort together?

Why this happens

Both substances affect how your blood clots, but in different ways. Aspirin thins the blood by stopping platelets (cells that help blood clot) from sticking together. St John's wort can also interfere with blood clotting and may irritate the lining of the stomach. When used together, these effects add up, making it harder for your body to stop any bleeding.

Use this combination with caution. If you are taking aspirin on a doctor's advice (for example, to prevent a heart attack or stroke), speak to your GP or pharmacist before starting St John's wort. Watch out for signs of bleeding, such as dark 'tarry' stools, coughing up blood, or bruises that appear for no reason.

Asthma

Do not take aspirin if you have a history of asthma, as it can trigger a severe, life-threatening asthma attack or worsening of breathing symptoms.

Children under 16 years old

Never give aspirin to children or teenagers under 16 unless specifically prescribed by a doctor, due to the risk of Reye’s syndrome, a rare but fatal condition affecting the brain and liver.

Taking other prescription medicines (e.g. warfarin, the pill, antidepressants)

St John's wort stops many essential prescription medicines from working correctly. You must check with a pharmacist before taking it if you use any other medication, especially blood thinners, hormonal contraception, or antidepressants.

Alcohol

Drinking alcohol while taking aspirin can increase the risk of stomach irritation and bleeding. It is best to limit alcohol intake, especially if you take aspirin regularly.

Caffeine (Coffee, Tea, Energy Drinks)

St John's wort may increase sensitivity to caffeine, potentially leading to feelings of anxiety, a racing heart, or jitteriness.

Foods high in Tyramine (Aged cheeses, cured meats, fermented products)

Although rare with modern preparations, St John's wort can theoretically interact with tyramine-rich foods, which may lead to a sudden increase in blood pressure.

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.