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

Why this happens

Both sertraline and St John's Wort work by increasing the levels of serotonin in the brain. When used at the same time, they have an 'additive effect', pushing serotonin levels far too high. Additionally, St John's Wort can change how the liver breaks down certain medicines, which can make the levels of sertraline in your blood unpredictable.

What you should do

Do not take St John's Wort if you are already taking sertraline. If you are currently taking both, you should contact your GP or pharmacist immediately for advice before stopping either medication, as stopping antidepressants suddenly can also cause side effects. If you experience severe confusion, a very high fever, or tremors, seek emergency medical help.

Important precautions

Serotonin Syndrome

Do not take St John's wort and sertraline together. Combining them can cause dangerously high levels of serotonin, leading to a life-threatening condition called serotonin syndrome. Symptoms include shivering, diarrhoea, confusion, and severe muscle stiffness.

Drug Interactions (Contraception and Anticoagulants)

St John's wort makes many essential medicines less effective, including the contraceptive pill and blood thinners like warfarin. This can lead to unplanned pregnancy or an increased risk of blood clots.

Food and drink warnings

Alcohol

You should avoid or strictly limit alcohol intake. Both substances affect the brain, and alcohol can increase the risk of side effects like drowsiness, dizziness, and impaired concentration. Combining alcohol with St John's Wort may also increase the risk of a rare but serious condition called serotonin syndrome.

Grapefruit juice

Avoid drinking large amounts of grapefruit juice. Grapefruit contains compounds that can increase the levels of sertraline in your blood, which may increase the risk of side effects.

Foods high in Tyramine (e.g., aged cheeses, cured meats, fermented products)

While the risk is lower than with older types of antidepressants, some people taking St John's Wort may experience a rise in blood pressure if they consume very large amounts of foods high in tyramine. Use these foods in moderation.

Using other medicines

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.