Insomnia affects 20 to 30 percent of all adults, according to the NYU Medical Center’s Sleep Disorder Clinic website. Its definition includes difficulty falling asleep and staying asleep, as well as waking too early and waking unrefreshed. If you’re among that 20 to 30 percent, many herbs and herbal teas have a mild sedative effect that may help you get to sleep and sleep more soundly.

Chamomile

Perhaps the best-known of all herbal teas, chamomile has a long history of use as a gentle sleep aid. Despite its traditional reputation, little research exists to back up its efficacy. Medline Plus, maintained by the National Library of Medicine and the National Institutes of  Health, gives chamomile a “C” grade–unclear scientific evidence for this use–for treatment of sleep disorders and insomnia.

Valerian

Hippocrates, the father of medicine, recommended valerian as a sleep aid. Modern science bears out its traditional use, with numerous studies reporting that valerian increases sleep quality and the ease of falling asleep. The beneficial effects appear to increase with nightly use over one to four weeks.Germany’s Commission E approves valerian for use as a sleep aid.

Lemon Balm

The ancient Greeks and Romans recommended lemon balm to reduce anxiety and promote sleep. Many modern herbal sleep aids combine lemon balm with valerian or hops. Lemon balm and valerian proved to be effective in improving sleep in one study of 918 children with sleep disorders, according to the Urban Herbs website atGeorgetownUniversity.

Kava

Kava is a traditional drink in thePacificIslands. The drink is brewed from the ground roots of a tall shrub. Research suggests that kava may be an effective treatment for anxiety, and some studies have shown that kava has a mild sedative effect. However, many countries have banned the use of kava, and the U.S. Food and Drug Administration warns that it may cause severe liver damage.

Passionflower

Passionflower, also known as passiflora, is native to the southeastern United States, but grows throughout Europe now. It has similar but weaker effects to kava and valerian, according to the University of Maryland Medical Center’s website. Medline reports that some initial studies support its traditional use as a sedative, but that further study is needed to prove it definitively.