St. John's Wort Benefits, Side Effects and Drug Interactions

St. John's wort benefits are best studied for mild to moderate low mood. Research reviewed by the U.S. National Center for Complementary and Integrative Health suggests the herb may work better than a placebo for mild or moderate depression over up to 12 weeks, but it interacts with many medicines, so talk to a doctor or pharmacist before trying it.

Key takeaways

• St. John's wort (Hypericum perforatum) is a yellow-flowered plant used for centuries in traditional European herbalism.
• Studies suggest it may help mild to moderate depression; evidence for severe depression and for use beyond 12 weeks is uncertain.
• It can weaken many medications, including birth control pills, warfarin, cyclosporine, digoxin and some HIV and cancer drugs.
• Combining it with SSRIs or other antidepressants can cause serotonin syndrome, which can be serious.
• It can make your skin more sensitive to sunlight and is not recommended in pregnancy or while breastfeeding.

What is St. John's wort?

St. John's wort is a flowering plant native to Europe that now grows wild in many parts of North America. The flowers and leaves are dried and made into capsules, tablets, teas and liquid extracts. Its name comes from the fact that it traditionally blooms around June 24, the feast day of St. John the Baptist.

The plant contains several active compounds, most notably hyperforin and hypericin. Researchers think these compounds affect brain chemicals involved in mood, such as serotonin, dopamine and norepinephrine, although the exact way the herb works is not fully understood.

What are the benefits of St. John's wort?

Most research on St. John's wort has looked at depression. According to the National Center for Complementary and Integrative Health (NCCIH), studies suggest that:

• It appears to be more effective than a placebo for mild or moderate depression.
• For these milder cases, it appears to be about as effective as standard antidepressants in several reviews, including a 2016 systematic review and meta-analyses published in 2017 and 2023.
• It is not clear whether it helps severe depression or works for longer than 12 weeks.

Cleveland Clinic notes that results are mixed: some studies found no benefit over placebo for major depressive disorder, and there is not enough evidence that it helps anxiety. Small studies have looked at menopausal hot flashes and somatic symptom disorder, while research on ADHD, IBS, OCD, PMS and quitting smoking has not clearly shown a benefit.

Depression is a medical condition that deserves proper care. If low mood is affecting your daily life, see your doctor before trying any herb, so that you can talk about all your options together.

Where does St. John's wort fit in a mood support routine?

Many traditional formulas pair St. John's wort with other botanicals. Mood Effex mood support is one example: it combines St. John's wort with six other traditional botanicals, including morinda root, albizzia flower and dong quai, plus our fulvic mineral extract, and is designed to support a balanced mood as part of a healthy lifestyle. It is available now with a Buy 2 Get 1 Free offer. Because it contains St. John's wort, the same interaction cautions in this article apply, so check with your pharmacist first.

What are the side effects of St. John's wort?

NCCIH says St. John's wort appears to be safe for most adults who are not taking other medicines when used for up to 12 weeks. Possible side effects include:

• Trouble sleeping, restlessness and dizziness
• Diarrhea, nausea and dry mouth
• Fatigue and skin tingling
• Sexual side effects
• Sun sensitivity: large oral doses can cause severe skin reactions after sun exposure, especially in people with fair skin or who take other light-sensitizing medicines

Which medications interact with St. John's wort?

This is the most important safety issue. St. John's wort speeds up the liver enzymes that break down many drugs, which can make those drugs less effective. Combined with serotonin-raising medicines, it can also cause too much serotonin activity. The table below summarizes interactions listed by NCCIH and Cleveland Clinic.

This list is not complete. Always give your pharmacist a full list of your medications and supplements before starting St. John's wort, and never stop or switch an antidepressant on your own.

Who should avoid St. John's wort?

• People who are pregnant or breastfeeding
• Anyone taking antidepressants or any of the medicines above
• Anyone scheduled for surgery (Cleveland Clinic advises stopping at least five days before)

How long does St. John's wort take to work, and how is it taken?

Studies of St. John's wort generally ran for several weeks, up to about 12 weeks, so it is not a quick fix. Cleveland Clinic notes that the most common amount studied is 300 to 400 mg of extract three times a day with meals, but the strength of products varies widely. Follow the label and your health care provider's advice.

Herbs work best alongside everyday habits that support mood. See our guides to natural ways to support a balanced mood, how stress and sleep affect mood and the winter blues.

When to reach out for help

If you feel hopeless, have thoughts of harming yourself, or your low mood lasts more than two weeks, please reach out. In the United States and Canada, you can call or text 988 (Suicide and Crisis Lifeline) any time. In an emergency, call 911. Your family doctor is also a good first step.

Frequently asked questions

Is St. John's wort safe to take every day?

NCCIH says it appears safe for most adults not taking other medicines for up to 12 weeks, and some studies suggest longer. The main risks are drug interactions and sun sensitivity, so check with a pharmacist first.

Can I take St. John's wort with an antidepressant?

No, not without your doctor's direct guidance. Combining it with SSRIs or other serotonin-affecting medicines can cause serotonin syndrome, which can be serious.

Does St. John's wort help with anxiety?

Cleveland Clinic says there is not enough evidence that St. John's wort helps anxiety. Most research has focused on mild to moderate depression.

Does St. John's wort affect birth control?

Yes. It can make birth control pills less effective, which raises the chance of an unplanned pregnancy. Use a backup method and talk to your pharmacist.

The bottom line on St. John's wort benefits

The best-supported St. John's wort benefits are for mild to moderate low mood over short periods, while its interactions with common medicines are well documented. Talk to your doctor or pharmacist before trying it, and keep taking any prescribed medication as directed.

Sources

• National Center for Complementary and Integrative Health: St. John's Wort
• Cleveland Clinic: St. John's Wort

This article is general information, not medical advice. St. John's wort can interact with many medications, including antidepressants, birth control pills and blood thinners. Talk to your doctor or pharmacist before taking Mood Effex or any herbal supplement, and do not stop or change a prescribed medication without medical advice.