St John's Wort: benefits, side effects and uses

Siski Green / 04 January 2021

It is widely used to treat mild to moderate depression. It is also used for seasonal affective disorder (SAD), anxiety, listlessness and sleep problems.



Dubbed ‘nature’s Prozac’ St John’s Wort is renowned the world over for helping relieve the symptoms of depression. It grows wild in Europe and Asia.

What is St John’s Wort used for?

St John’s Wort is mainly used to treat symptoms of depression, but it should never be taken alongside prescribed antidepressants so always speak to your GP if you have any concerns about your medication.

What’s the history of St John’s Wort?

The St John's Wort plant, Hypericum perforatum, with its yellow star-shaped flowers, has been used for centuries to treat psychological disorders such as depression and anxiety. It’s named as it is because it was said to flower at the time of St John’s day (St John the Baptist). It has been used since ancient times as a ‘magic potion’ as it was believed to hold magical powers and was even recommended for keeping dragons at bay, most likely because of its effects on the mind.

What’s the best way to take St John’s Wort?

You can find supplements in tablet or capsule form, you can also find tea, oils and liquid extracts. The flowers and buds are what hold the active ingredients so it’s important to use those parts of the flowers if you are growing your own.

Does St John’s Wort really work?

The plant contains various active ingredients such as hypericin and hyperforin that may have an effect similar to antidepressants. They work by helping to improve messaging in the brain, helping to keep levels of mood-related substances such as serotonin and dopamine at healthy levels. One of the aspects of St John’s Wort that appeals to patients is that it doesn’t necessarily produce the same side effects as anti-depressant medications such as loss of libido for example.

A review of studies published in Systematic Review found that St John’s Wort helps to relive mild and moderate depression significantly more than a placebo, with fewer side effects.

As anxiety can sometimes be a symptom of depression there’s good reason to believe St John’s Wort would also relieve anxiety symptoms.

Where can I get St John’s Wort?

St John’s Wort is widely available in chemists, supermarkets and healthfood shops. You’ll find it as a supplement, drops, and tinctures.

How long does St John’s Wort take to work?

Patients report changes within around 12 weeks of taking St John’s Wort, around 300mg per day.

What are the side effects of taking St John’s Wort?

St John’s Wort can make you more sensitive to the sun, along with possibly causing indigestion and allergic reactions.

Are there any contraindications when taking St John’s Wort?

If you are on anti-depressant medication it is essential you see your GP before taking St John’s Wort as it may have an effect, potentially triggering serotonin syndrome where dangerously high levels are reached and symptoms such as irregular heartbeat, confusion, headache and fever may be experienced.

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The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.