St. John's Wort and Depression Patient Handout: Question & Answer

The National Center for Complementary and Alternative Medicine (NCCAM) has developed this fact sheet on the use of St. John’s wort (SJW) for depression. It is part of a series intended to help consumers make informed decisions about whether to use complementary and alternative medicine (CAM) for a disease or medical condition.

Key Points

St. John’s wort is an herb that has been used for centuries for medicinal purposes, including to treat depression. The composition of SJW and how it works are not well understood.

There is some scientific evidence that SJW is useful for treating mild-to-moderate depression. However, recent studies suggest that SJW is of no benefit in treating major depression of moderate severity. More research is required to help us know whether SJW has value in treating other forms of depression.

SJW interacts with certain drugs, and these interactions can be dangerous. It is important to inform all of your health care providers about any therapy that you are currently using or considering, including any dietary supplements. This is to help ensure a safe and coordinated course of care.

1. What is St. John’s wort?

St. John’s wort (Hypericum perforatum in Latin) is a long-living plant with yellow flowers. It contains many chemical compounds. Some are believed to be the active ingredients that produce the herb’s effects, including the compounds hypericin and hyperforin. How these compounds actually work in the body is not yet known, but several theories have been suggested. Preliminary studies suggest that SJW might work by preventing nerve cells in the brain from reabsorbing the chemical messenger serotonin, or by reducing levels of a protein involved in the body’s immune system functioning.

2. For what medicinal purposes has SJW been used?

SJW has been used for centuries to treat mental disorders as well as nerve pain. In ancient times, doctors and herbalists wrote about its use as a sedative and treatment for malaria as well as a balm for wounds, burns, and insect bites. Today, SJW is used by some people to treat mild-to-moderate depression, anxiety, or sleep disorders.

3. What is depression?

Depression is a medical condition that affects nearly 19 million Americans each year. A person’s mood, thoughts, physical health, and behavior all may be affected. Symptoms commonly include:

  • Ongoing sad mood
  • Loss of interest or pleasure in activities that the person once enjoyed
  • Significant change in appetite or weight
  • Oversleeping or difficulty sleeping
  • Agitation or unusual slowness
  • Loss of energy
  • Feelings of worthlessness or guilt
  • Difficulty “thinking,” such as concentrating or making decisions
  • Recurrent thoughts of death or suicide

The three major forms of depressive illness are described below. Each can vary from person to person in terms of symptoms experienced and the severity of depression.

In major depression, people experience a sad mood or loss of interest or pleasure in activities for at least two weeks. In addition, they have at least four other symptoms of depression. Major depression can be mild, moderate, or severe. If it is not treated, it can last for six months or more.

In minor depression, people experience the same symptoms as major depression, but they are fewer in number and are less disabling. Symptoms last at least six months but less than two years continuously.

In dysthymia, a milder, but more chronic form of depression, people experience a depressed mood for at least two years (one year for children), accompanied by at least two other symptoms of depression.

In bipolar disorder, also called manic depression, a person has periods of depressive symptoms that alternate with periods of mania. Symptoms of mania include an abnormally high level of excitement and energy, racing thoughts, and behavior that is impulsive and inappropriate.

4. Why is SJW used as an alternative therapy for depression?

Some patients who take antidepressant drugs do not experience relief from their depression. Other patients have reported unpleasant side effects from their prescription medication, such as a dry mouth, nausea, headache, or effects on sexual function or sleep.

Sometimes people turn to herbal preparations because they believe “natural” products are better for them than prescription medications, or that natural products are always safe. Neither of these statements is true.

Finally, cost can be a reason. SJW costs less than many antidepressant medications, and it is sold without a prescription (over the counter).

5. Does SJW work as a treatment for depression?

There has been scientific research to try to answer this question. In Europe, results from a number of scientific studies have supported the effectiveness of certain SJW extracts for depression. An overview of 23 clinical studies found that the herb might be useful in cases of mild-to-moderate depression. The studies, which included 1,757 outpatients, reported that SJW was more effective than a placebo and appeared to produce fewer side effects than some standard antidepressants (Linde et al. British Medical Journal, 1996).

Other studies conducted recently have found no benefit from the use of SJW for certain types of depression. For example, the results of a study funded by Pfizer Inc., a pharmaceutical company, found that SJW, when compared with placebo, was not effective for treating major depression (Shelton et al. JAMA, 2001).

In addition, several components of the National Institutes of Health (NIH) funded a large, carefully designed research study to find out whether SJW extract benefits people with major depression of moderate severity. This clinical trial (a research study in people) found that SJW was no more effective for treating major depression of moderate severity than placebo (Hypericum Depression Trial Study Group. JAMA, 2002).

6. Are there any risks to taking SJW for depression?

Yes, there are risks in taking SJW for depression.

Many so-called “natural” substances can have harmful effects—especially if they are taken in too large a quantity or if they interact with something else the person is taking.

Research from NIH has shown that SJW interacts with some drugs—including certain drugs used to control HIV infection (such as indinavir). Other research shows that SJW can interact with chemotherapeutic, or anticancer, drugs (such as irinotecan). The herb may also interact with drugs that help prevent the body from rejecting transplanted organs (such as cyclosporine). Using SJW limits these drugs’ effectiveness.

Also, SJW is not a proven therapy for depression. If depression is not adequately treated, it can become severe and, in some cases, may be associated with suicide. Consult a health care practitioner if you or someone you care about may be experiencing depression.

People can experience side effects from taking SJW. The most common side effects include dry mouth, dizziness, diarrhea, nausea, increased sensitivity to sunlight, and fatigue.

Source: National Center for Complementary and Alternative Medicine. Available at: Accessed Aug. 19, 2005.