Valerian (Valeriana officinalis) is a plant native to Europe and Asia, and naturalized to the United States. Hippocrates described the medicinal uses of the roots and rhizomes of valerian, and Galen wrote about its use for insomnia in the second century AD.
Valerian is added to tea (ie, herbal infusion) products that are marketed to induce sleep (eg, Sleepytime Extra Herbal Tea by Celestial Seasonings). Unlike true teas, which are marketed as foods, products that contain valerian are marketed in the United States as dietary supplements. Dietary supplement classification allows manufacturers to make structure and function claims, such as “promotes relaxation.”
Like other plant products, valerian contains many chemicals, such as valerenic acid and valepotriates, that might contribute, either alone or collectively, to its pharmacologic activity. The mechanism of hypnotic activity is unknown, but increasing levels of gamma-aminobutyric acid (GABA) has been proposed. Activation of GABA receptors induces drowsiness. Whether GABA in valerian can cross the blood/brain barrier is unclear, and GABA concentrations in valerian can vary significantly depending on the time of plant harvesting.
Clinical studies on the effectiveness of valerian as a hypnotic have yielded mixed results. A valerian extract (530 mg) improved sleep quality in postmenopausal women with sleep disturbances (30% experienced improvement vs 4% with placebo). A trial of patients with sleep disturbances while undergoing cancer chemotherapy found that valerian extract (450 mg) was no better than placebo, but a secondary analysis suggested some improvement in fatigue. A sleep laboratory study of older women with insomnia reported no difference between valerian extract (300 mg) and placebo in a randomized controlled trial. A recent meta-analysis of clinical trials found that the effects of valerian were similar to those of placebo in terms of sleep onset latency, sleep duration, sleep efficiency, sleep quality, or duration of wakefulness after sleep onset.
For short-term use, valerian appears to be safe. Most clinical trials on sleep have spanned 4 weeks or less; one study evaluated safety and efficacy for 8 weeks. The safety of long-term continuous use is unknown. The safety of valerian in pregnancy and lactation is also unknown.
Valerian has not been associated with clinically significant drug interactions. In theory, valerian could be additive with other central nervous system depressants, but this has not been demonstrated in clinical research.
Remind patients that good sleep hygiene, such as going to bed around the same time every night; avoiding bright light (eg, a computer screen) at bedtime; and relaxing by reading, listening to soothing music, or taking a hot bath, also may be helpful.