Herbs & Supplements:
Valerian
Valeriana officinalis
Principal Proposed Uses
•
Insomnia
Other Proposed Uses
•
Anxiety, Nervous Stomach
Over 200 plant species belong to the genus Valeriana, but the one most commonly used as an herb is Valeriana officinalis. The root is used for medicinal purposes.
Galen recommended valerian for insomnia in the second century A.D. From the sixteenth century onward, this herb became popular as a sedative in Europe (and later, the United States). Scientific studies on valerian in humans began in the 1970s, leading to its approval as a sleep aid by Germany's Commission E in 1985.
As for most herbs, we are not exactly sure which ingredients in valerian are most important.1,2 Early research focused on a group of chemicals known as valepotriates, but they are no longer considered candidates. A constituent called valerenic acid is presently under study, but its role is far from clear.
Our understanding of how valerian functions is similarly incomplete. Several studies suggest that valerian affects GABA, a naturally occurring amino acid that appears to be related to the experience of anxiety.3–6 Conventional tranquilizers in the Valium family are known to bind to GABA receptors in the brain, and valerian may work similarly. However, there are some significant flaws in these hypotheses, and the reality is that we don't really know how valerian works.7,8
What Is Valerian Used for Today?
Valerian is commonly recommended as a mild treatment for occasional insomnia. However, evidence from the best study on valerian suggests that it is most useful when taken over an extended period of time for chronic sleep disorders.9
Valerian is used to treat anxiety as well, although there is much more scientific evidence for the herb kava.
Finally, valerian is sometimes suggested as a treatment for a nervous stomach; however, as of yet, there is no evidence for this use.
What Is the Scientific Evidence for Valerian?
Insomnia
The best study to date of valerian's effectiveness in treating insomnia involved 121 people followed for 28 days.10 Half of the participants took 600 mg of an alcohol-based valerian extract 1 hour before bedtime, the other half placebo.
At first, placebo and valerian were running neck and neck. But by the end of the study, the participants treated with valerian were definitely sleeping better.
Although positive, these results are a bit confusing, because in another large study valerian was immediately more effective than placebo. This trial followed 128 subjects who had no sleeping problems.11 On three consecutive nights they took either valerian, a valerian-hops combination, or placebo. The results showed that on the nights they took valerian alone, participants fell asleep faster than when they were taking placebo or the combination. (However, valerian-hops has been found effective in another trial, described below). It is possible that different subspecies of valerian with differing medicinal effects have been used in the various trials.
Additional evidence for valerian's effectiveness comes from a double-blind placebo-controlled study of 78 elderly patients.12 In this case, sleep improved by the end of the study, at 14 days.
In addition, a 28-day double-blind trial of 75 individuals with insomnia compared valerian (600 mg at bedtime) with the standard drug oxazepam (10 mg at bedtime).13 The results showed no differences in effectiveness.
A double-blind comparative study that enrolled 46 patients compared the effects of the standard drug bromazepam to a mixture of valerian and hops with either treatment taken one-half hour before bed.14 The results suggest that the two treatments were equally effective.
Finally, the combination of valerian and lemon balm has been tried for insomnia. A rather poorly designed 30-day, double-blind, placebo-controlled study of 98 individuals without insomnia found marignal evidence that a valerian–lemon balm combination improved sleep quality as compared to placebo.15 However, a double-blind crossover study of 20 people with insomnia compared the benefits of the sleeping drug Halcion (0.125 mg) against placebo and a combination of valerian and lemon balm, and failed to find the herb effective.16 The drug, however, did prove effective.
Anxiety
Forty-eight participants were placed under situations of "social stress" in a double-blind study of valerian.17 Individuals in the treated group reported less anxiety.
One study purported to also find evidence that valerian helps reduce reactions to stressful situations, but because it lacked a placebo group, the results mean little.18
Animal Studies
Both valerenic acid and whole valerian have been found to produce calming, sleepiness, and reduced activity in laboratory mice.19–22 Both substances also help prevent seizures. Since most pharmaceutical tranquilizers also reduce seizures, the latter result can be taken as additional indirect evidence of valerian's tranquilizing powers.
Warning: Do not try to substitute valerian for your antiseizure medication. The herb is not powerful enough.
Dosage
For insomnia, the standard dosage of valerian is 2 to 3 g of dried herb, 270 to 450 mg of an aqueous valerian extract, or 600 mg of an ethanol extract, taken 30 to 60 minutes before bedtime.23
According to the study mentioned previously that used this dosage, valerian may require weeks to reach its full effects. The same amount, or a reduced dose, can be taken twice daily for anxiety.
Because of valerian's unpleasant odor, European manufacturers have created odorless valerian products. However, these are not yet widely available in the United States.
Valerian is not recommended for children under 3 years old.24
Safety Issues
Valerian is on the FDA's GRAS (generally recognized as safe) list, and is approved for use as a food. In animals, it takes enormous doses of valerian to produce any serious adverse effects.25
In a suicide attempt, one young woman took approximately 20 g of valerian (20 to 40 times the recommended dose). Only mild symptoms developed, including stomach cramps, fatigue, chest tightness, tremors and light-headedness. All of these resolved within 24 hours, after two treatments with activated charcoal.26 Her lab tests—including tests of her liver function—remained normal. Keep in mind that this does not mean that you can safely exceed the recommended dose!
One report did find toxic results from herbal remedies containing valerian mixed with several other herbal ingredients, including skullcap. Four individuals who took these remedies later developed liver problems.27 However, skullcap products are sometimes contaminated with the liver-toxic herb germander, and this could have been the explanation.
There have also been about 50 reported cases of overdose with a combination preparation called Sleep-Qik, containing valerian as well as conventional medications.28,29 Researchers specifically looked for liver injury, but found no evidence that it occurred.
There are some safety concerns about valepotriates, constituents of valerian, because they can affect DNA and cause other toxic effects. However, valepotriates are not present to a significant extent in any commercial preparations.30,31
Although no animal studies or controlled human trials have found evidence that valerian ever causes withdrawal symptoms when stopped, one case report is sometimes cited in support of the possibility that this might occur.32 It concerns a 58-year-old man who developed delirium and rapid heartbeat after surgery. According to the patient's family, he had been taking high doses of valerian root extract (about 2.5 to 10 g per day) for many years. His physicians decided that he was suffering from valerian withdrawal. However, considering the many other factors involved (such as multiple medications and general anesthesia), it isn't really possible to conclude that valerian caused his symptoms.
Except for the unpleasant odor, valerian generally causes no side effects.33,34 A few people experience mild gastrointestinal distress, and there have been rare reports of people developing a paradoxical mild stimulant effect from valerian.
Valerian does not appear to impair driving ability or produce morning drowsiness when it is taken at night.35–38 However, there does appear to be some impairment of attention for a couple of hours after taking valerian.39 For this reason, it isn't a good idea to drive immediately after taking it.
There have been no reported drug interactions with valerian. A 1995 study found no interaction between alcohol and valerian as measured by concentration, attentiveness, reaction time, and driving performance.40 However, valerian extracts may prolong drug-induced sleeping time in mice, rats, and rabbits.41,42 Thus, it is possible that valerian could compound the effects of other central-nervous-system depressants.
Safety in young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established.
Interactions You Should Know About
If you are taking medications for insomnia or anxiety such as benzodiazepines, don't take valerian in addition to them.
View References
Last reviewed March 2002 by Medical Review Board
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