Valerian is an herbal supplement made from the root of Valeriana officinalis, a flowering plant native to Europe and Asia. It has been used for centuries as a natural sleep aid and mild sedative, and today it remains one of the most popular over-the-counter remedies for insomnia and anxiety worldwide. In several European countries, including Germany, Switzerland, and France, valerian root extract is an accepted nonprescription medicine for treating stress, nervous tension, and disturbed sleep.
How Valerian Works in the Brain
Valerian’s calming effects trace back to how its active compounds interact with a specific brain chemical called GABA (gamma-aminobutyric acid). GABA is the nervous system’s main “slow down” signal. It reduces the firing of nerve cells, which is why boosting GABA activity leads to feelings of relaxation and sleepiness. Prescription sedatives like benzodiazepines work on the same system.
The root contains several classes of active compounds, but two matter most. The first group, valerenic acid and its derivatives, binds directly to GABA receptors with high precision. Research published in the American Journal of Psychiatry identified the exact binding site on GABA receptors where valerenic acid attaches, and showed that its anxiety-reducing effects disappeared entirely in lab models when that specific receptor subunit was altered. The second group, called valepotriates, also contributes to sedation, though their role is less well understood. Together, these compounds produce a mild version of the same calming pathway that pharmaceutical sedatives use.
Valerian for Sleep
Sleep improvement is valerian’s most studied use. A systematic review and meta-analysis of randomized controlled trials found that people taking valerian were 1.8 times more likely to report improved sleep quality compared to those taking a placebo. Two of four studies measuring how long it took people to fall asleep found meaningful reductions: 14 to 17 minutes faster on average. That’s a modest but real effect, roughly comparable to what some people experience with melatonin.
The evidence comes with caveats. Many of the clinical trials had small sample sizes, lasted a month or less, and used varying preparations and doses, making it hard to draw firm conclusions. Valerian appears to work better as a cumulative treatment than a quick fix. Most studies showing positive results used the supplement nightly for two to four weeks, while single-dose studies produced less consistent results. If you try valerian for sleep, give it at least two weeks before judging whether it helps.
Valerian for Anxiety
Valerian also shows promise for reducing anxiety, though the evidence is thinner than for sleep. A double-blind crossover trial in hemodialysis patients found that valerian significantly reduced state anxiety scores compared to placebo, with reductions roughly double those seen in the control group. Other studies have reported benefits for anxiety in menopausal women and people with minor anxiety symptoms. Still, no large-scale trial has definitively established valerian as a standalone anxiety treatment, and most researchers consider the evidence preliminary.
Common Doses and Preparations
Valerian comes in several forms: capsules containing dried root or concentrated extract, liquid tinctures, and teas brewed from the dried root. The root itself contains between 0.5% and 5% volatile oils, and standardized extracts are typically calibrated to contain 0.8% valerenic acid.
For sleep, the most commonly studied dose is 300 to 600 mg of a standardized extract taken 30 minutes to one hour before bedtime. For daytime anxiety or nervous tension, clinical studies have used 100 mg three times daily, or total daily doses of 400 to 600 mg of dried extract. If you prefer the raw root (as in teas), doses range from 0.3 to 3 grams up to three times daily. Products sold in the United States vary enormously, with recommended doses on labels ranging from 75 to 3,000 mg per day, so checking for standardization to valerenic acid content is one way to ensure consistency.
The U.S. Pharmacopeial Convention sets quality benchmarks for valerian products, requiring a minimum of 0.05% valerenic acid and 0.5% volatile oil in the raw root material. Looking for a USP or NSF certification mark on the label can help you identify products that meet these standards.
Side Effects and Safety
Valerian is generally well tolerated. The most commonly reported side effects are mild: daytime drowsiness, dizziness, and occasional stomach discomfort. Some people who stop taking valerian after prolonged use report withdrawal-like symptoms, which suggests it should be tapered rather than stopped abruptly if used daily for an extended period.
Liver toxicity has come up in a small number of case reports, but almost always when valerian was taken alongside other herbal products like skullcap or black cohosh. The National Institutes of Health rates valerian as a “probable rare cause” of liver injury, noting that no convincing cases of serious liver failure have been attributed to valerian alone. In the few reported cases, liver enzyme elevations appeared 3 to 12 weeks after starting the supplement and resolved within 2 to 4 months of stopping.
Because valerian acts on GABA receptors, combining it with alcohol, prescription sedatives, or other calming supplements could amplify drowsiness. One review examining valerian’s drug interaction potential concluded there is no strong clinical evidence for dangerous interactions, but the theoretical risk of additive sedation with other GABA-active substances is real enough to warrant caution. Avoid combining valerian with alcohol or sleep medications without understanding that the sedative effects may stack.
How Valerian Compares to Prescription Sleep Aids
Valerian is considerably milder than prescription options. Its effects on sleep onset and sleep quality, while statistically significant in some trials, are modest. You’re unlikely to feel the pronounced sedation that comes with pharmaceutical sleep medications. For many people, that’s actually the appeal: valerian offers a gentler nudge toward sleep without the heavy morning grogginess or dependency risk associated with stronger drugs. It fits best as an option for mild, occasional sleep difficulties or general nervousness rather than as a treatment for severe insomnia or clinical anxiety disorders.
In the United States, valerian is regulated as a dietary supplement, not a drug. This means manufacturers don’t need to prove efficacy before selling it, and product quality can vary significantly between brands. Choosing products with third-party testing certifications helps close that gap.