Valerian Root for Sleep

Valerian root is an herbal remedy that has been used for centuries to promote sleep and help relieve anxiety. Its documented use stretches back to ancient Greece, and many different cultures have adopted it over time. (1)

In the modern United States, valerian is available in many different formulations, and some of them are marketed specifically as sleep aids. But the regulatory framework for herbal supplements is extremely lax, and few if any specific products have undergone scientific studies to show their effectiveness in promoting sleep.

Some general studies of valerian have shown certain benefits when it comes to falling and staying asleep. But the studies’ designs, and their results, haven’t been consistent.

Here’s an overview of what the evidence says about taking valerian as a sleep aid, and factors you might want to consider before using it for this purpose.

Small Studies, Some Positive Results

Despite its long-standing reputation as a sleep aid, valerian hasn’t undergone serious clinical trials to evaluate its effectiveness in promoting sleep. That’s in part because clinical trials are extremely expensive, and no single company has a monopoly on valerian that could justify such a large — and risky — investment.

Studies on valerian and sleep have been mostly small, with different formulations, doses, and study populations being included. Some have specifically targeted people with insomnia (difficulty falling or staying asleep), while others have simply looked for sleep-related improvements in people who don’t report serious problems.

Because most studies of valerian for sleep have been small, looking at the results of several studies combined — known as a meta-analysis — is potentially more useful than focusing on any one study. There have been a few meta-analyses on valerian over the years.

One such analysis, published in the journal Sleep Medicine, included nine different studies on valerian. The researchers determined that all nine studies had flaws in their design, but in a rating of 1 to 5, three earned the highest rating of 5 for the lowest risk of bias in their design.

In one of these three studies, 128 participants were randomly assigned to take three different items on three different nights each, separated by nights when they took nothing: either 400 milligrams (mg) of a liquid valerian extract, a commercial supplement containing 60 mg of valerian and 30 mg of hops, or a placebo (inactive pill). Nobody knew which treatment was which, and each filled out a sleep questionnaire the next morning.

Compared with the placebo, the valerian extract significantly improved participants’ perceived ease of falling asleep, ease of staying asleep, and overall sleep quality. This result was even stronger among the 61 participants who identified as “poor sleepers” in a questionnaire at the beginning of the study. The commercial supplement, though, didn’t show any significant improvement over the placebo.

In the second highly rated study from the analysis, eight participants with insomnia were randomly assigned to take either 450 mg of valerian extract, 900 mg of the extract, or a placebo for four nights in a row during one week, repeated for a total of three weeks. They wore nighttime motion sensors on their wrists and filled out a questionnaire each morning.

Compared with the placebo, the 450 mg dose of valerian extract reduced the average time to fall asleep from 16 minutes to 9 minutes, and the questionnaires showed a perceived improvement in sleep quality. No improvement in sleep time was seen with the 900 mg dose, though, and it caused increased sleepiness the next morning.

In the third highly rated study, 121 participants with insomnia received either 600 mg of a commercial valerian supplement or a placebo for 28 nights in a row. Using questionnaires and other assessment tools, the researchers found that participants who took valerian saw improvements in falling asleep and sleep quality — especially during the second half of the study, after having taken the supplement for two weeks already. (2)

Limited Evidence of Effectiveness

Despite the encouraging results from the top-rated studies in the meta-analysis, the researchers’ overall conclusion, based on all nine studies, was that “the findings of the studies were contradictory” and “the evidence for valerian as a treatment for insomnia is inconclusive.” (2)

Other meta-analyses of studies on valerian since then haven’t been any more encouraging. One looked at 29 studies and found that “most studies found no significant differences between valerian and placebo either in healthy individuals or in persons with general sleep disturbance or insomnia.” (3)

Another analysis of 18 different studies found that the average reduction in time spent falling asleep from taking valerian as compared with a placebo was less than one minute. (4)

And an analysis of 14 studies on four different herbal supplements for insomnia — valerian, chamomile, kava, and wu ling — found “no statistically significant difference between any herbal medicine and placebo” in 13 different measures of efficacy. It also found that valerian was associated with more reported side effects than the other herbs or placebo. (5)

Low Risk, Possible Benefit

The good news on valerian as a sleep aid is that it appears to be safe to take regularly. While some people in studies have reported side effects such as drowsiness the next day, overall, “valerian is a safe herb associated with only rare adverse events,” as one analysis notes. (3)

So even though most studies haven’t found valerian to be an effective sleep aid, there’s little harm in trying it to see if it helps. But the different results seen in various studies offer an important lesson to anyone taking it: You may need to try a few different formulations, brands, or doses before you find one that’s effective.

Ultimately, what works for one person may not work for another — and trying it is the only way to know if valerian works for you as a sleep aid.