GradedHealth

Valerian

Last reviewed October 2026 · Based on 20 studies

Bottom line

Valerian may make some people feel their sleep is better, and several trials report this, but the evidence is small and mixed. It has not clearly shortened the time people take to fall asleep, and it has not been shown to treat insomnia or reduce anxiety.

What it helps with

  • Helps you sleep better — Mixed results, evidence grade C (Limited). Several placebo-controlled trials and a 2020 meta-analysis report better self-rated sleep, but the pooled effect is small and uncertain and other trials and reviews find no benefit; downgraded for inconsistency and small trials.
  • Helps you fall asleep faster — No effect, evidence grade C (Limited). Meta-analysis of 18 placebo-controlled trials found no meaningful difference in time to fall asleep; one small trial found a shorter time; downgraded for inconsistency and small trials.
  • Eases anxiety — Mixed results, evidence grade C (Limited). Eight trials pooled with high variation and possible publication bias; a 2022 network meta-analysis found insufficient evidence; one trial favoured valerian; downgraded for inconsistency and small trials.
  • Is well tolerated — Mixed results, evidence grade C (Limited). Umbrella review and one crossover trial report few problems, but a 2015 review found more adverse events than placebo and liver injury has been reported in case reports; downgraded for small trials and inconsistency.

What it is

Valerian (Valeriana officinalis) is a plant whose roots and rhizomes are used as a sleep aid, usually as capsules, tablets or tea. Products vary: the same herb can be a whole-root preparation or a standardised extract, and results differ between them [1].

How it might work

Proposed mechanism: valerenic acid in valerian may increase activity of GABA, a brain chemical that calms nerve activity. Benzodiazepine sleeping drugs act in a similar way [2].

What the research says

A 2020 meta-analysis of 10 placebo-controlled trials (1,065 people) found a small, not statistically certain improvement in self-rated sleep quality (effect size 0.36, 95% CI -0.08 to 0.81). Whole-root preparations showed a larger effect (0.83) than extracts (0.10), but that subgroup rests on four trials [1]. A 2010 meta-analysis of 18 placebo-controlled trials found valerian about 1.4 times as likely to be rated as improving sleep (RR 1.37, 95% CI 1.05-1.78), but time to fall asleep differed from placebo by only 0.7 minutes (95% CI -3.44 to 4.83) [3]. An umbrella review of eight systematic reviews found no clear evidence of benefit for insomnia, with a possible effect on subjective sleep quality only [4]. A 2023 umbrella review found valerian did not significantly improve sleep outcomes [5]. For anxiety, a 2020 meta-analysis of eight studies (535 people) reported high variation and possible publication bias, so the result is inconclusive [1]. A 2022 network meta-analysis found insufficient evidence that valerian reduces anxiety [6]. Individual trials are mixed: in an 8-week trial of 80 adults, a standardised extract improved sleep quality and anxiety scores compared with placebo [7], and 530 mg a night for 30 nights improved sleep quality after heart bypass surgery in 72 people [8].

Doses used in studies

Doses ranged from a single 1,600 mg dose tested for driving safety [2] to 530 mg a night for 30 nights [8]. The 8-week trial of a standardised extract does not state the dose in its abstract [7]. Many trials tested blends with other herbs, so their doses do not describe valerian alone [9][10].

Safety and interactions

An umbrella review of valerian for sleep reported a good safety profile [4]. A 2015 review of herbal medicines for insomnia found more adverse events per person with valerian than with placebo, though the abstract does not list them [11]. A randomised trial of a single 1,600 mg dose found no impairment of driving simulator performance [2]. Acute liver injury has been reported in a case report of a multi-herb sleep aid containing valerian [12]. We found no human trials of valerian's effects on common side effects at higher doses, upper intake limits, or pregnancy and breastfeeding. We also found no trials testing valerian with blood thinners, antidepressants, diabetes or blood-pressure medicines, or immunosuppressants. People with liver disease and those who take sedatives or other sleep medicines should ask a doctor first.

Caveats and open questions

Trials use different products, doses and measures, and most are small. Results are inconsistent across trials, and subjective ratings of sleep improve more readily than objective measures [4]. Many trials test valerian in blends, so it is unclear how much valerian alone contributes [10][9]. One 2-week trial was supported by tablets donated by the manufacturer, which had no role in design or analysis [9]. We found no recruiting trials of valerian alone.

References

  1. Valerian Root in Treating Sleep Problems and Associated Disorders-A Systematic Review and Meta-Analysis.. J Evid Based Integr Med, 2020.
  2. Effects of valerian on subjective sedation, field sobriety testing and driving simulator performance.. Accid Anal Prev, 2016.
  3. Effectiveness of Valerian on insomnia: a meta-analysis of randomized placebo-controlled trials.. Sleep Med, 2010.
  4. Does valerian work for insomnia? An umbrella review of the evidence.. Eur Neuropsychopharmacol, 2024.
  5. Complementary and alternative treatments for insomnia disorder: a systematic umbrella review.. J Sleep Res, 2023.
  6. Medicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis.. Pharmacol Res, 2022.
  7. Standardized Extract of Valeriana officinalis Improves Overall Sleep Quality in Human Subjects with Sleep Complaints: A Randomized, Double-Blind, Placebo-Controlled, Clinical Study.. Adv Ther, 2024.
  8. Efficacy of Valerian Extract on Sleep Quality after Coronary Artery bypass Graft Surgery: A Triple-Blind Randomized Controlled Trial.. Chin J Integr Med, 2021.
  9. Efficacy and safety of a polyherbal sedative-hypnotic formulation NSF-3 in primary insomnia in comparison to zolpidem: a randomized controlled trial.. Indian J Pharmacol, 2013.
  10. Effect of a nutraceutical combination on sleep quality among people with impaired sleep: a randomised, placebo-controlled trial.. Sci Rep, 2024.
  11. Herbal medicine for insomnia: A systematic review and meta-analysis.. Sleep Med Rev, 2015.
  12. Acute Liver Injury After Long-Term Herbal "Liver Cleansing" and "Sleep Aid" Supplement Use.. J Emerg Med, 2021.