Important safety information for people taking St John’s Wort preparations

St John’s Wort (SJW) preparations are unlicensed herbal remedies. Their levels of active ingredients can vary from one preparation to another. They are widely used in the UK being available from pharmacies, health food shops and herbal practitioners.

St John’s Wort preparations may interfere (interact) with medicines, stopping them from working properly. If you are taking medicines it may not be safe for you to take St John’s Wort preparations. The advice in the box is provided below to help you understand how this may affect you.

‘I am currently taking a St John’s Wort preparation, and I am not taking any medicine(s)’

Advice: If you buy a medicine from a pharmacy or are prescribed a medicine by your doctor you must tell your pharmacist or doctor about the St John’s Wort preparation.

‘I am already taking medicine(s) but I would like to start taking a St John’s Wort preparation’

Advice: You must not take a St John’s Wort preparation until you have checked with your pharmacist or doctor that it is safe for you to do so.

Epilepsy or fits: ‘I am on tablets for epilepsy/fits and I am also taking a St John’s Wort preparation’

Transplant: ‘I am on tablets following a transplant and I am also taking a St John’s Wort preparation’

Asthma or chronic bronchitis : ‘I am on theophylline tablets for my chest and I am also taking a St John’s Wort preparation’ Heart condition: ‘I am taking digoxin for a heart condition and I am also taking a St John’s Wort preparation’ Blood clots : ‘I am taking warfarin to thin my blood and I am also taking a St John’s Wort preparation’

You will need to stop taking the St John’s Wort preparation as it may stop your medicine from working properly. However, you should see your pharmacist or doctor before stopping the St John’s Wort preparation as the dose of your medicine may need to be altered to prevent side effects.

Contraceptive pill: ‘I am on the pill and I am also taking a St John’s Wort preparation’

Advice: You should stop taking the St John’s Wort preparation as it may stop your pill from working. Continue to take your contraceptive pill as normal. There is no need to see your pharmacist or doctor urgently, however, mention it when you next consult your doctor or are dispensed a medicine.

Depression: ‘I am on treatment for depression and I am also taking a St John’s Wort preparation’

Advice: You should stop taking the St John’s Wort preparation as it may stop your medicine from working. There is no need to see your pharmacist or doctor urgently, however, mention it when you next consult your doctor or are dispensed a medicine.

HIV: ‘I am HIV positive and on treatment and I am also taking a St John’s Wort preparation’

Advice: You should stop taking the St John’s Wort preparation and see your doctor who may suggest you have your HIV viral load checked.

General: ‘I am currently taking both a St John’s Wort preparation and a prescribed medicine not mentioned above’

Advice: Tell your pharmacist or doctor that you are taking a St John’s Wort preparation when you are next dispensed a medicine or consult your doctor.