A yellow-flowered herb.
Why it’s used: Traditionally used to support mood. It interacts with many medicines, including the contraceptive pill and antidepressants; check with your GP or pharmacist first.
St John's wort, Hypericum perforatum, is a wild plant with bright yellow, star-shaped flowers that grows across Europe, including the UK, along roadsides and in meadows. It traditionally flowers around midsummer and St John's Day on 24 June, which is how it got its name. Hold a leaf to the light and you will see tiny translucent dots, which is what perforatum refers to.
It has been part of European herbal tradition for centuries and is traditionally used to support mood. Its compounds of interest include hypericin and hyperforin. It is also one of the herbs most known for interacting with medicines, because it speeds up the way the liver and gut clear many drugs, which can make them less effective. In the UK, it is one of the few herbs where the medicines regulator has issued specific interaction warnings.
On labels you will see St John's wort, Hypericum perforatum herb extract, or extracts standardised to hypericin. As a food supplement ingredient it has no authorised health claim.
3 findings behind this ingredient. Hover a card for the detail and the source.
Cochrane systematic review of 29 randomised double-blind trials with 5,489 patients with major depression. Hypericum extracts had higher response rates than placebo, similar response to standard antidepressants and fewer dropouts due to side effects.
Meta-analysis of 27 clinical trials with 3,808 patients comparing St John's wort with SSRI antidepressants over 4 to 12 weeks. Response and remission were similar, and discontinuation rates were significantly lower with St John's wort.
Meta-analysis of 14 clinical trials with 2,270 adults with depression, comparing St John's wort with SSRIs and placebo. The authors concluded it lowered Hamilton depression scores with fewer adverse effects.
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It can. St John's wort can lower the levels of hormonal contraceptives in the body, which may make them less effective and cause breakthrough bleeding. If you use hormonal contraception, speak to your GP or pharmacist before taking it.
No, not unless a doctor specifically advises it. Combining St John's wort with some antidepressants can cause serotonin-related side effects, which can be serious. If you take an antidepressant, talk to your GP or pharmacist first.
Many. Well-known examples include the contraceptive pill, antidepressants, warfarin, ciclosporin, some HIV medicines and some epilepsy medicines. Because the list is long, always check with your pharmacist before combining it with any prescribed or over-the-counter medicine.
Videos from doctors, research scientists and registered dietitians, for general education. They are independent of Nutra Formulations, do not refer to our products and are not medical advice for you.
The Three Best Herbs to Fight Depression
Dr Tracey Marks, MD, psychiatrist · Dr. Tracey Marks on YouTube
Information only, not medical advice. If you take medication, are pregnant or breastfeeding, speak to your GP or pharmacist first.
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