Valerian has an ancient reputation for sleep

The Irish Times
Health Supplement, p. 13
10 June 2008

DOES IT WORK? Valerian and sleep disorders

VALERIAN IS one of the world’s top-selling herbal remedies. This is surprising given how bad it smells. Its odour has been compared to that of socks badly in need of washing or a sharp cheese that starving mice would avoid.

Nonetheless, valerian has been recommended since ancient Greek and Roman times for sleeping difficulties.

The root and rhizome (underground stem) are soaked in either alcohol or water to give an extract. Traditional herbalists recommend using the alcohol extract (or tincture). However, most products are available as tablets made from dried extracts. The composition of the extracts has been shown to vary widely depending on how they are made.

Evidence from studies

A recent systematic review of valerian research found 37 studies. However, much variation existed in how these studies were conducted, which makes overall recommendations difficult. The most recent and highest quality studies were conducted on tablets made from alcohol extracts.

Studies comparing valerian with a placebo found it no better at speeding up how quickly people fell asleep or for improving sleep quality. However, three studies compared valerian with benzodiazepines (sleeping pills from the same group as Valium). These showed that valerian was as effective as the pharmaceutical drugs.

Studies testing water extracts of valerian against placebo were much more variable in their results. Most of these studies were small, older and of lower quality. A few showed valerian was no better than placebo, but most showed benefits on some, but not all, tests.

Another group of studies tested combination products of valerian along with hops and/or lemon balm. These herbs are alleged to improve sleep themselves and to have even better effects in combination. However, the studies had variable results, mostly showing that the combinations were no more effective than placebo.

In contrast to pharmaceutical sleeping tablets, valerian does not have an immediate sedative effect. General recommendations usually state that it needs to be taken consistently for one to two weeks before improvements will be seen. While this approach to taking valerian has not been tested specifically, most of the placebo-controlled studies that lasted two weeks or longer did not find valerian more effective than placebo.

Problematic aspects

The various studies did not report any serious adverse effects with valerian. Some mild side effects were reported, such as headache, intestinal problems and morning drowsiness. The side effects with benzodiazepines were more frequent and more problematic.

Valerian should not be taken along with alcohol, benzodiazepines or other sedatives in case they enhance one another’s effects in unpredictable ways. Concerns have been expressed that valerian may interfere with how other drugs are eliminated from the body, but little research has been conducted in this area.


Valerian is a herbal remedy with an ancient reputation for improving sleep quality. It appears to be safe and does not have as many side effects as commonly prescribed sleeping tablets. While people often report beneficial results, most recent studies have not found it any more effective than placebo. However, a few studies have found it to be similar in effectiveness to benzodiazepines.

Such contradictory results may arise because of the variety of valerian products that are available. These are made from different species and prepared in different ways.

The studies themselves have also used numerous ways to measure the quality of people’s sleep, which can be difficult to measure accurately.

Given its lack of side effects, valerian may be worth trying. Most studies use 400-900mg valerian extract, taken about two hours before bedtime. If no improvements are seen after two to three weeks, other options should be investigated.
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2 Responses to Valerian

  1. Kate says:

    I slept like a baby after taking valerian, however when I woke in the morning, I was extreemly dizzy, to the point where I was falling over. My stomach was not good either. It was as though I had drank too much alcohol

  2. Dónal says:

    Unfortunately, some people get the type of reaction you mention. Liquid extracts usually contain alcohol, but the herb itself can lead to these feelings.

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