The search for calming therapies is as old as civilization itself. Alcohol, opiates, and other illicit drugs have been used for centuries. More recently, prescription drugs, such as benzodiazepines, have become overwhelmingly popular. Because of their addictive properties and the strict control placed on these tranquilizer prescriptions, however, the quest continues unabated for more accessible and socially acceptable methods to take the edge off. Readily available around the world, valerian (Valeriana officinalis) is widely used to treat insomnia, anxiety, and restlessness.1


Valerian extract is derived from the roots and rhizomes of a perennial flowering herb.2 Valerian has a characteristic odor that is readily obvious when a bottle of the supplement is opened. The use of valerian as a sleep aid and anxiolytic evolved out of 17th- and 18th-century medicine. In modern times, valerian was listed as a remedy in the U.S.

Pharmacopoeia from 1820 to 1936 and was an official entry in the National Formulary from 1888 to 1946.3At some point in their lives, one in eight people in the United States (32 million total) will complain about insomnia to a health-care provider.4 Approximately 12.5% of Americans are given prescriptions for anxiolytics over the course of a year, making the benzodiazepine class of drugs one of the most popular in the United States.5,6 To be classed as an anxiolytic, a drug must exhibit one or more of these qualities: anxiety relief, hypnotic tendencies, muscle relaxation, anticonvulsant action, or amnesic.5

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Because this drug class also carries a significant potential for abuse and dependence, it is labeled Schedule IV under the Controlled Substances Act.5 Given this profile of traditional medicine’s agents for treating anxiety and insomnia, it is not surprising that some patients search for safer, more easily accessed treatments.

Mechanism of action

The chemical composition of valerian includes sesquiterpenes in the form of volatile oil, iridoids, alkaloids, furanofuran, lignans, and free amino acids, such as g-aminobutyric acid (GABA), tyrosine, arginine, and glutamine.7 According to one review, the “sesquiterpene components of the volatile oil are believed to be responsible for most of valerian’s biologic effects,” but the combined synergistic effects of all the components probably are required for the total clinical response.7 The GABA effect is the dominant pharmacokinetic response that gives valerian its anxiolytic and sleep-inducing action. GABA is the most abundant amino-acid neurotransmitter in the brain and controls the balance between excitation and inhibition.8 By increasing that neurotransmitter, valerian sways the “balance” from the excitation to the inhibition side and decreases anxiety and wakefulness.

Several trials have shown efficacy in treating insomnia with valerian. Though the numbers of participants are small (<500), the results have shown enhancement of both subjective and lab-validated sleep quality.7 Sleep latency as well as subjective improvement in quality of sleep were improved in all trials. A systematic review of randomized trials in 2003, however, concluded that the level of evidence and outcome strengths were insufficient to recommend valerian for the treatment of insomnia.7

As an anxiolytic, valerian is frequently used in combination with other herbs, such as passion flower and St. John’s wort. While studies of these combinations have also been small, statistically significant improvement in participants’ subjective ratings of anxiety was shown.7 One trial in particular used the highly reproducible format of the Hamilton Anxiety Scale, which allows the subject to self-score his feelings.7 This test, first published in 1959, uses a 14-item symptom rating that is then scored based on the severity of the patient’s responses (Table 1).9

Safety, dosage, side effects, and drug interactions

Rare cases of headache, nausea, and dizziness have been reported. To prevent the depressant effect, valerian should not be used in combination with other drugs or substances known to produce central nervous system sedation (e.g., anesthetics, other sedatives, or alcohol). The recommended dose is usually 300-600 mg of ground root/rhizome powder. Valerian is best taken 30-60 minutes before bedtime.10

Valerian is reasonably inexpensive and is not habit-forming. Depending on the brand, per-capsule costs range from 8 to 30 cents. As always, be aware of the potential risk for allergic reaction with a botanical product.


A safe, nonaddictive, effective, and accessible sleep aid, valerian should be considered by any clinician attempting to treat mild insomnia or anxiety. With the significant concerns surrounding prescription therapies, not the least of which is cost, this simple and inexpensive supplement is worthy of attention.


1. National Center for Complementary and Alternative Medicine. Valerian. Available at: Accessed February 7, 2007.

2. Fetrow CW, Avila JR. Professional’s Handbook of Complementary & Alternative Medicines. Springhouse, Pa.: Springhouse Corporation; 1999:650-651.

3. American Botanical Council. Valerian. Available at: February 7, 2007.

4. Wrong Diagnosis. Statistics about insomnia. Available at: Accessed February 1, 2007.

5. Center for Substance Abuse Research. Benzodiazepines. Available at: Accessed February 7, 2007.

6. Emedicine. Sedative, Hypnotic, Anxiolytic Use Disorders. Available at: Accessed February 7, 2007.

7. Hadley S, Petry JJ. Valerian. Am Fam Physician. 2003;67:1755-1758.

8. Insight Journal. GABA (Gamma-Aminobutyric Acid) Neurotransmitter. Accessed February 7, 2007.

9. Hamilton M. The assessment of anxiety states by rating. Br J Med Psychol. 1959;32:50-55.