How does valerian work

For example, none of the studies checked the success of the blinding, none calculated the sample size necessary for seeing a statistical effect , only one partially controlled prebedtime variables [ 15 ], and only one validated outcome measures [ 13 ]. Two other randomized, controlled trials published after the systematic review described above [ 11 ] are presented below:. Although the results of some studies suggest that valerian may be useful for insomnia and other sleep disorders, results of other studies do not.

Interpretation of these studies is complicated by the fact the studies had small sample sizes, used different amounts and sources of valerian, measured different outcomes, or did not consider potential bias resulting from high participant withdrawal rates.

Overall, the evidence from these trials for the sleep-promoting effects of valerian is inconclusive. Many chemical constituents of valerian have been identified, but it is not known which may be responsible for its sleep-promoting effects in animals and in in vitro studies. It is likely that there is no single active compound and that valerian's effects result from multiple constituents acting independently or synergistically [18, reviewed in 19].

Two categories of constituents have been proposed as the major source of valerian's sedative effects. The first category comprises the major constituents of its volatile oil including valerenic acid and its derivatives , which have demonstrated sedative properties in animal studies [ 6 , 20 ]. However, valerian extracts with very little of these components also have sedative properties, making it probable that other components are responsible for these effects or that multiple constituents contribute to them [ 21 ].

The second category comprises the iridoids , which include the valepotriates. Valepotriates and their derivatives are active as sedatives in vivo but are unstable and break down during storage or in an aqueous environment, making their activity difficult to assess [ 6 , 20 , 22 ]. A possible mechanism by which a valerian extract may cause sedation is by increasing the amount of gamma aminobutyric acid GABA, an inhibitory neurotransmitter available in the synaptic cleft.

Results from an in vitro study using synaptosomes suggest that a valerian extract may cause GABA to be released from brain nerve endings and then block GABA from being taken back into nerve cells [ 23 ].

In addition, valerenic acid inhibits an enzyme that destroys GABA [reviewed in 24]. Valerian extracts contain GABA in quantities sufficient to cause a sedative effect, but whether GABA can cross the blood-brain barrier to contribute to valerian's sedative effects is not known.

Glutamine is present in aqueous but not in alcohol extracts and may cross the blood-brain barrier and be converted to GABA [ 25 ]. Levels of these constituents vary significantly among plants depending on when the plants are harvested, resulting in marked variability in the amounts found in valerian preparations [ 26 ]. In the United States, valerian is sold as a dietary supplement, and dietary supplements are regulated as foods, not drugs. Therefore, premarket evaluation and approval by the Food and Drug Administration are not required unless claims are made for specific disease prevention or treatment.

Because dietary supplements are not always tested for manufacturing consistency, the composition may vary considerably between manufacturing lots. Few adverse events attributable to valerian have been reported for clinical study participants. Headaches, dizziness, pruritus , and gastrointestinal disturbances are the most common effects reported in clinical trials but similar effects were also reported for the placebo [ ].

In one study an increase in sleepiness was noted the morning after mg of valerian was taken [ 14 ]. Investigators from another study concluded that mg of valerian LI did not have a clinically significant effect on reaction time, alertness, and concentration the morning after ingestion [ 27 ].

Several case reports described adverse effects , but in one case where suicide was attempted with a massive overdose it is not possible to clearly attribute the symptoms to valerian [ ]. Valepotriates, which are a component of valerian but are not necessarily present in commercial preparations, had cytotoxic activity in vitro but were not carcinogenic in animal studies [ ].

Valerian might have additive therapeutic and adverse effects if taken with sedatives, other medications, or certain herbs and dietary supplements with sedative properties [ 39 ].

These include the following:. Individuals taking these medications or supplements should discuss the use of valerian with their healthcare providers. Although valerian has not been reported to influence laboratory tests , this has not been rigorously studied [ 5 , 36 , 39 ].

Medical libraries are a source of information about medicinal herbs. Other sources include Web-based resources such as PubMed. This fact sheet by the Office of Dietary Supplements provides information that should not take the place of medical advice. We encourage you to talk to your healthcare providers doctor, registered dietitian, pharmacist, etc.

Any mention in this publication of a specific brand name is not an endorsement of the product. Updated: March 15, Find ODS on:. Strengthening Knowledge and Understanding of Dietary Supplements. Health Information Health Information. Valerian Fact Sheet for Health Professionals. Valerian Health Professional Other Resources. Table of Contents Key points What is valerian?

What are common valerian preparations? What are the historical uses of valerian? What clinical studies have been done on valerian and sleep disorders? How does valerian work? What is the regulatory status of valerian in the United States? Can valerian be harmful? Who should not take valerian? This is because taking high doses of valerian root during the day can lead to daytime sleepiness. Many small clinical studies have been done to test the efficacy and safety of valerian root for sleep.

Results have been mixed: In a placebo-controlled study , for example, women with insomnia took mg of valerian extract 30 minutes before bedtime for two weeks.

The women reported no significant improvements in the onset or quality of sleep. Likewise, a review of 37 studies found that most clinical trials of valerian root showed no differences between valerian root and placebo on sleep. These studies were done in both healthy individuals and people with insomnia. But the National Institutes of Health NIH describes an old study showing that mg of valerian root extract did significantly improve sleep compared to placebo in healthy volunteers.

Participants reported improvements in the time needed to fall asleep, quality of sleep, and number of middle of the night awakenings. The NIH also noted a clinical trial in which people with insomnia taking mg of dried valerian root had decreased symptoms of insomnia compared to the placebo after 28 days of treatment. Research on the use of valerian root in treating anxiety is somewhat lacking.

One small study in 36 patients with generalized anxiety disorder found that 50 mg of valerian root extract given three times a day for four weeks significantly reduced one measure of anxiety compared to placebo. Other anxiety studies used slightly higher dosages.

The U. Also avoid combining it with sedative drugs, such as barbiturates e. Valerian root also has a sedative effect, and the effect can be addictive. Valerian root may also increase the effects of anesthesia. Powdered valerian root is available in capsule and tablet form, as well as a tea. You can purchase valerian root easily online or in drugstores.

Be sure to read the product labels and directions before taking valerian root. Some products contain dosages of valerian root that are higher than the above recommended amounts. Keep in mind, though, that there is no standard dose of valerian root. Valerian root can make you drowsy. The best time to take valerian root for sleep is right before bedtime. You might have an underlying condition, like sleep apnea, or a psychological disorder, which requires evaluation.

Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice. Jacquelyn Cafasso has been in a writer and research analyst in the health and pharmaceutical space since she graduated with a degree in biology from Cornell University. A native of Long Island, NY, she moved to San Francisco after college, and then took a brief hiatus to travel the world.

Some researchers now think you may need to take valerian for a few weeks before it begins to work. However, in another study, valerian was more effective than placebo almost immediately. Other studies show that valerian reduces the time it takes to fall asleep and improves the quality of sleep.

Unlike many prescription sleeping pills, valerian may have fewer side effects, such as morning drowsiness. But not every study has found that valerian had a positive effect. One review of several studies found that valerian probably doesn't work to treat insomnia. So the evidence remains contradictory. Valerian is often combined with other sedating herbs, such as hops Humulus lupulus and lemon balm Melissa officianalis , to treat insomnia.

In one study of postmenopausal women, a combination of valerian and lemon balm helped reduce symptoms of insomnia. Valerian is a perennial plant that is native to Europe and grows up to 2 feet tall. It is grown to decorate gardens, but also grows wild in damp grasslands. Straight, hollow stems are topped by umbrella-like heads.

Its dark green leaves are pointed at the tip and hairy underneath. Small, sweet-smelling white, light purple, or pink flowers bloom in June. The root is light grayish brown and has little odor when fresh. The root of the plant is used as medicine and is pressed into fresh juice or freeze-dried to form powder.

Valerian fluid extracts and tinctures are sold in alcohol or alcohol-free glycerite bases. Powdered valerian is available in capsule and tablet form, and as a tea. Valerian root has a sharp odor. It is often combined with other calming herbs, including passionflower Passiflora incarnata , hops Humulus lupulus , lemon balm Melissa officinalis , skullcap Scutellaria lateriflora , and kava Piper methysticum to mask the scent.

However, kava has been associated with liver damage, so avoid it. Valerian is often standardized to contain 0. Preliminary studies suggest that valerian may help improve concentration and impulsiveness among primary school children. DO NOT give valerian to a child without first talking to your doctor. For insomnia, valerian may be taken 1 to 2 hours before bedtime, or up to 3 times in the course of the day, with the last dose near bedtime.

It may take a few weeks before the effects are felt. The use of herbs is a time-honored approach to strengthening the body and treating disease.

However, herbs can trigger side effects, and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.

Valerian is generally regarded as safe. Most studies show no harmful effects on fertility or fetal development, but more research is needed. Experts advise pregnant and nursing women to avoid taking valerian. Some people may have a paradoxical reaction to valerian, feeling anxious and restless after taking it instead of calm and sleepy. For most people, valerian does not appear to cause dependency.

Nor does it cause withdrawal symptoms for most. But there are a few reports of withdrawal symptoms when valerian has been used over very long periods of time. If you want to stop taking valerian, lower your dose gradually rather than stopping all at once. Don't use valerian while driving, operating heavy machinery, or doing other things that require you to be alert.

If you are currently being treated with any of the following medications, you should not use valerian without talking to your health care provider. Valerian may slow down how quickly certain drugs are broken down by the liver. Many medications rely on the liver to break them down, so it's possible that in some cases, too much of these drugs could build up in the body.

To be safe, ask your doctor before taking valerian if you are also taking any other medications. The same is true of other herbs with a sedating effect, such as chamomile, lemon balm, and catnip. Because valerian is broken down by certain liver enzymes, it may interact with other drugs that are broken down by the same enzymes.

These may include many different medications, including but not limited to the following:. Valerian may increase the effects of anesthesia.