Introduction

This fact sheet provides basic information about the herb St. John's wort--common names, uses, potential side effects, and resources for more information. St. John's wort is a plant with yellow flowers.

Common Names--St. John's wort, hypericum, Klamath weed, goat weed

Latin Name--Hypericum perforatum

What It Is Used For

• St. John's wort has been used for centuries to treat mental disorders and nerve pain.
• In ancient times, herbalists wrote about its use as a sedative and a treatment for malaria, as well as a balm for wounds, burns, and insect bites.
• Today, St. John's wort is used by some for depression, anxiety, and/or sleep disorders.

How It Is Used

The flowering tops of St. John's wort are used to prepare teas and tablets containing concentrated extracts.

What the Science Says

• There is some scientific evidence that St. John's wort is useful for treating mild to moderate depression. However, two large studies, one sponsored by NCCAM, showed that the herb was no more effective than placebo in treating major depression of moderate severity.
• NCCAM is studying the use of St. John's wort in a wider spectrum of mood disorders, including minor depression.