Valerian is a plant native to Europe and Asia; it also grows in North America.
Valerian has been used medicinally since the times of early Greece and Rome; Hippocrates wrote about its uses. Historically, valerian was used to treat nervousness, trembling, headaches, and heart palpitations.
Today, valerian is used as a dietary supplement for insomnia, anxiety, and other conditions such as depression and menopause symptoms.
The roots and rhizomes (underground stems) of valerian are used to make capsules, tablets, and liquid extracts, as well as teas.