What Is It?

Valerian is a herbal medicine made from the root of the perennial Valeriana officinalis. It’s been used since at least the time of Hippocrates and is generally considered a sedative, although in a few people it seems to have the reverse effect.

Use It For

Insomnia and other sleep troubles, calming nerves

The Science

A meta-analysis published in The American Journal of Medicine found that patients taking valerian were 80 percent more likely to report improved sleep than those taking a placebo, although some of the studies reviewed had evidence of bias or used faulty methods. Valerian has minimal known side effects, and the USDA classifies it as Generally Recognized as Safe (GRAS).

How to Take It

Valerian seems to be most effective as a sleep aid when taken 30 minutes to 2 hours before bedtime, for about a month. Doses range from 400 to 900 mg. For anxiety, the recommended dose is 120 to 200 mg, three to four times daily. Some studies have suggested valerian’s effects on sleep don’t kick in for about 14 days, while other research indicates it works immediately. Don’t take valerian for more than a month without talking to your doctor.

What’s That Smell?

Although valerian plants have a sweet-smelling flower once used for perfume, the root—which is the part used for supplements—can emit an unpleasant odor. Supplements often combine it with herbs such as hops or lemon balm (also sedatives) to suppress the scent.