St. John’s Wort: An Overview of its Use as an Antidepressant and Anxiolytic

Most prescription antidepressants are very effective for treating depression, and some prescription antidepressants are effective for treating anxiety. There are herbal products that are effective for treating depression, but are these herbal products effective at treating anxiety? St. John’s wort is the most effective herbal product at treating depression. Is this herb effective for treating anxiety? This article explains St. John’s wort, its use for treating depression and information relating to its use for treating anxiety.


St. John’s wort is a dietary supplement. Dietary supplements are regulated differently than prescription drugs or over the counter drugs. The Food and Drug Administration (FDA) monitors drugs for safety, efficacy, and purity. The FDA does not monitor dietary supplements for safety, efficacy, or purity.

Why is this important?

Not all dietary supplements are safe, effective, and pure. St. John’s wort is not safe, it is not effective for all conditions it is claimed to be effective for, and some unscrupulous companies are selling impure or adulterated products. St. John’s wort is not safe because it interacts with some drugs. If you do not take drugs it interacts with, it is relatively safe. Its effectiveness is discussed below.

If I choose to use dietary supplements, how can be sure the products I use don’t hurt me?

  • Do stay informed on the good AND bad aspects of each supplement you decide to take.
  • Do purchase USP or GMP certified supplements. These certifications indicate that the manufacturer has made an effort to ensure consistency, purity, and quality in those certified products. If the product is USP or GMP certified, this will be displayed on the product’s label.
  • Do educate yourself with quality information, and be skeptical of information given to you from those attempting to sell you something.
  • Don’t believe everything you hear about a supplement.
  • Don’t continually purchase different brands of a supplement. Find one brand that suits your needs, and only buy that brand.
  • Don’t purchase products that you no longer need.
  • Don’t purchase products that no longer work for you.

What is St. John’s wort used for?

St. John’s wort is used for mild to moderate depression, and is as effective as most antidepressants for depression of mild to moderate severity. It acts in a similar way to some prescription antidepressants. If you are taking prescription antidepressants, avoid using St. John’s wort without first talking to your physician or pharmacist.

St. John’s wort has been studied for effectiveness at treating anxiety. Unfortunately, St. John’s wort does not appear to be effective at treating anxiety when compared to a placebo.

How does St. John’s wort work?

St. John’s wort increases serotonin, norepinephrine, and dopamine levels within the brain. It is believed that this increase ultimately leads to a reduction in depression symptoms and, with some drugs, a reduction in anxiety symptoms.

What else should I know about St. John’s wort?

St. John’s wort, when taken with certain prescription antidepressants, can cause serotonin syndrome. This syndrome is a life-threatening condition that presents as rapid heart rate, increased body temperature, loss of consciousness, or death. Although this syndrome is rare, it is better to be safe than dead, so ask your pharmacist or physician if any of your medications interact with St. John’s wort. The most common over the counter drug that interacts with St. John’s wort which can result in serotonin syndrome is dextromethorphan, a cough suppressant. This drug can be found in many cough and cold medicines.

St. John’s wort interacts with many prescription and non-prescription drugs. St. John’s wort stops oral contraceptives (birth control pills) from working. Also, some organ transplant drugs are rendered ineffective by St. John’s wort. As a take home message, ask your pharmacist if any of your prescriptions interact with St. John’s wort.

Do not use St. John’s Wort if you are pregnant or lactating. Do not give to children under 18 years old.


St. John’s wort helps mild to moderate depression. It does not help anxiety. It interacts with many drugs. Do not take St. John’s wort if you are already taking an antidepressant. Do not take St. John’s wort if you are on an oral contraceptive. Do not use over the counter cough suppressants in conjunction with St. John’s wort. Ask your pharmacist if St. John’s wort interacts with your prescriptions. Stay well-informed and only purchase products that have GMP or USP certifications.

Joey Sweeney DPH-4
Doctor of Pharmacy


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4. Davidson J. St. John’s wort in generalized anxiety disorder: three case reports. Psychopharmacology 2001; 21:635-636.