Valerian root benefits: what the research does and doesn't show

The evidence doesn't support valerian root, at any dose or form, as a treatment for insomnia or an anxiety disorder. Multiple systematic reviews agree it's generally well tolerated; where they disagree is whether it beats a placebo at all, and the most recent, most rigorous trials found that it didn't.

What the evidence doesn't support

It doesn't support valerian root as a treatment for insomnia, generalized anxiety disorder, panic disorder, or any other diagnosed sleep or anxiety condition. A 2024 umbrella review of eight systematic reviews concluded that valerian has a good safety profile but does not have empirical support for insomnia when judged by objective or quantitative sleep measures — despite being one of the most widely used herbal sleep aids and one often recommended by general practitioners and psychiatrists (PMID 38359657). A 2007 systematic review of 37 studies reached a similar conclusion in its own title: "safe but not effective." In that review, the most recent and methodologically rigorous trials found no significant effect on sleep compared with placebo (PMID 17517355).

What the trials found

A 2006 meta-analysis pooled 16 randomized, placebo-controlled trials — 1,093 people in total — testing valerian for sleep. Using a simple yes/no measure of whether sleep improved, valerian showed a statistically significant benefit over placebo (relative risk 1.8, 95% CI 1.2–2.9), but the authors found evidence of publication bias in that specific result, and doses across the pooled trials varied widely, from 225 mg to 1,215 mg a day (PMID 17145239).

A 2010 meta-analysis of 18 placebo-controlled trials found a similar split. On the same kind of simple improved/not-improved measure, valerian showed a modest benefit (relative risk 1.37, 95% CI 1.05–1.78). But on the two measures that used numbers instead of a yes/no answer — time to fall asleep and a standardized sleep-quality scale — there was no significant difference from placebo (mean difference 0.70 minutes for sleep onset; standardized mean difference −0.02 for sleep quality). The review's authors concluded that valerian's effectiveness hadn't been demonstrated with quantitative or objective measurements (PMID 20347389).

A 2020 systematic review pooled 10 trials (1,065 people) that used repeated dosing and numeric sleep-quality outcomes; the combined effect was small and not statistically significant (Hedges' g 0.36, 95% CI −0.08 to 0.81). Splitting those same 10 trials by preparation, whole dried root scored higher (0.83, 95% CI 0.03 to 1.62) than concentrated extract (0.10, 95% CI −0.02 to 0.22) — a difference the reviewers flagged as a possible explanation for inconsistent results elsewhere in the literature. That whole-root subgroup was only 4 small trials with a wide confidence interval, not a settled finding (PMID 33086877).

Individual trials in that same 2020 review varied just as widely. A web-based trial of 405 people with trouble sleeping found a modestly better global self-rating after 600 mg a day for 14 days (p=0.04), with similar trends favoring valerian on sleep quality, night awakenings and sleep duration, and no serious adverse events. A smaller trial of 16 older women with trouble sleeping found no significant difference from placebo on sleep-lab measurements or self-rated sleep after 300 mg a day for two weeks. And a trial of 14 elderly poor sleepers found a single 405 mg dose had no measurable effect, while the same 405 mg dose taken three times a day for a week changed some sleep-stage measurements on a sleep study without improving how quickly people fell asleep or how they rated their own sleep quality (PMID 33086877).

The evidence on anxiety is thinner still. A 2006 Cochrane review searched specifically for randomized trials of valerian in people with a diagnosed anxiety disorder and found exactly one eligible trial: 36 people with generalized anxiety disorder, over 4 weeks, comparing valerian, a placebo, and a prescription anxiety medication. Valerian showed no significant difference from placebo on the main anxiety rating scale used in that trial. The reviewers concluded there wasn't enough evidence to draw any conclusion about valerian for anxiety disorders, in either direction (PMID 17054208).

A 2020 review separately pooled 8 trials (535 people) using a broader definition of anxiety that included situational anxiety, such as the stress of a medical or dental procedure, not only diagnosed anxiety disorders. That pooled analysis showed high heterogeneity between trials (I²=93%) and clear evidence of publication bias. Results split by preparation again: outcomes were more consistently positive in the two trials using whole root, and more variable across the trials using extract. With only two whole-root trials, the reviewers themselves called that too little data to draw a conclusion from (PMID 33086877).

Questions people ask

Is valerian root good for sleep?

The reviews disagree with each other, and that disagreement is itself informative. Some meta-analyses find a modest benefit on simple yes/no measures of sleep improvement; the more rigorous, more recent, and more objective the measurement, the less likely a trial is to find a significant effect. The most recent umbrella review of the whole field concluded there's no empirical support for treating insomnia with valerian.

Is valerian root good for anxiety?

Only one trial has tested valerian in a diagnosed anxiety disorder, and it found no significant difference from placebo. Broader trials that included situational or non-clinical anxiety have been inconsistent, with high statistical heterogeneity and evidence of publication bias — the reviewers who pooled that data called it too limited to draw a conclusion from.

What does valerian root do?

In a test tube and in animal research, compounds in valerian — valerenic acid especially — interact with the same brain chemistry involved in calming and sedation. Whether that translates into a measurable effect from a capsule or a cup of tea is the open question the studies above address, and mostly answer no.

Valerian root benefits for women?

One small trial of 100 female college students found that 630 mg of valerian extract taken twice daily during the last week of the menstrual cycle, for three cycles, improved emotional, behavioral and physical premenstrual symptom severity compared with placebo, which had no effect. That's a single trial, not replicated elsewhere in this file, and premenstrual symptoms are a different question from the sleep and anxiety research above.

Valerian root benefits for men?

None of the trials reviewed here isolated a male-specific outcome or population. There's no research to report that's specific to men.

Does valerian root do anything for hair?

No trial we reviewed measured hair-related outcomes. There's no research basis for that claim in either direction.

Does valerian root tea work the same as capsules?

Most of the trials above tested extract or whole-root capsules, not brewed tea specifically, so tea hasn't been isolated as its own variable in this research. See what is valerian root? for how the forms differ.

When to talk to a doctor

Trouble sleeping or an anxiety disorder that interferes with daily life, work or relationships is worth raising with a doctor, especially if it's persistent. Valerian root is not a treatment for insomnia, generalized anxiety disorder, panic disorder, or any other diagnosed condition, and nothing in the research above supports using it as a substitute for an evaluation, therapy, or medication a doctor might recommend. If you're pregnant, nursing, or take a prescription medication — especially anything sedating — talk to a doctor before adding any supplement, valerian included.