Valerian

The ancient Greeks and Romans used a valerian-like root called phu, which cannot be identified with certainty as V. officinalis. Dioscorides used it for warming, for the urinary tract, for menstrual cramps and for liver disease ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}.

From around 1800, European pharmacy writers recommended valerian root for cramps and convulsive disorders, epilepsy, hysterical complaints, worms and nervous fever ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}.

Twentieth-century German authors used it for nervous agitation, nervous sleeplessness and nervous palpitations, and for nervous exhaustion, mental overwork, headache, and stomach cramps and colic ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}. The German Commission E (1985) approved it for nervousness and sleep disorders, taken as a tea or tincture or added to a full bath ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}.

The British Herbal Pharmacopoeia (1976) gave valerian for hysterical states, excitability, insomnia, hypochondriasis, migraine, cramp, intestinal colic, rheumatic pains and period pain ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}. Martindale’s Extra Pharmacopoeia (1967) listed it for hysteria and other nervous conditions, and as a carminative ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}.

Sayre’s materia medica (1917) described valerian root as a “gentle nerve stimulant and antispasmodic”, used for hysterical disorders ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}.

In Pakistan, valerian root and rhizome are used in traditional formulations for spinal cord disorders, nervous debility, nervous disorders during menopause, insomnia from nervous exhaustion and mental overwork, neurosis, hysteria and epilepsy. The same sources describe it as harmful to the kidneys if taken in large doses or for a long time ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}.

In an early crossover study of 128 people, a 400 mg aqueous extract shortened self-rated time to fall asleep and improved sleep quality, most in self-described poor sleepers ^{8Reference 8Leathwood PD et al. · 1982Aqueous extract of valerian root improves sleep quality in manView study →}.

Bent (2006) reviewed 16 trials (1,093 patients). The six that reported sleep quality as improved or not showed a significant benefit (RR 1.8, 95% CI 1.2–2.9), with evidence of publication bias ^{2Reference 2Bent S et al. · 2006Meta-analysisValerian for sleep: a systematic review and meta-analysisView study →}.

Fernández-San-Martín (2010) pooled 18 RCTs. Valerian improved sleep quality rated as yes or no (RR 1.37), but there was no difference in time to fall asleep (mean difference 0.70 min) or on sleep-quality scales ^{3Reference 3Fernández-San-Martín MI et al. · 2010Meta-analysisEffectiveness of Valerian on insomnia: a meta-analysis of randomized placebo-controlled trialsView study →}.

Shinjyo (2020) reviewed 60 studies and concluded valerian is safe and effective for subjective sleep quality. It attributed the inconsistent results to variable extract quality and found more reliable effects with whole root ^{1Reference 1Shinjyo N et al. · 2020Meta-analysisValerian Root in Treating Sleep Problems and Associated Disorders — A Systematic Review and Meta-AnalysisView study →}.

Taibi (2007) reviewed 37 studies and found that most showed no difference from placebo. None of the most recent and most rigorous studies found a significant effect ^{4Reference 4Taibi DM et al. · 2007Systematic reviewA systematic review of valerian as a sleep aid: safe but not effectiveView study →}.

In a crossover trial in 16 older women with insomnia, 300 mg of extract for two weeks did not improve self-reported sleep, polysomnography or actigraphy compared with placebo. Time awake after first falling asleep rose from baseline on valerian ^{11Reference 11Taibi DM et al. · 2009RCTA randomized clinical trial of valerian fails to improve self-reported, polysomnographic, and actigraphic sleep in older women with insomniaView study →}.

A phase III trial in 227 people with cancer (450 mg for eight weeks) missed its primary sleep endpoint, although fatigue scores improved in an exploratory analysis ^{12Reference 12Barton DL et al. · 2011RCTThe use of Valeriana officinalis in improving sleep in patients undergoing cancer treatment: a phase III RCT (NCCTG N01C5)View study →}.

A 2024 umbrella review concluded that valerian has a good safety profile but lacks empirical support for insomnia ^{6Reference 6Valente V et al. · 2024ReviewDoes valerian work for insomnia? An umbrella review of the evidenceView study →}.

Some trials in specific groups were positive. In 100 postmenopausal women, 530 mg twice daily for four weeks improved sleep quality ^{9Reference 9Taavoni S et al. · 2011RCTEffect of valerian on sleep quality in postmenopausal women: a randomized placebo-controlled clinical trialView study →}. After heart bypass surgery, 530 mg nightly for 30 nights improved sleep quality ^{10Reference 10Zare Elmi HK et al. · 2021RCTEfficacy of Valerian Extract on Sleep Quality after Coronary Artery Bypass Graft Surgery: A Triple-Blind Randomized Controlled TrialView study →}. In 80 adults with sleep complaints, a standardised extract improved sleep-quality scores and actigraphy-measured sleep latency over eight weeks ^{7Reference 7Chandra Shekhar H et al. · 2024RCTStandardized Extract of Valeriana officinalis Improves Overall Sleep Quality: A Randomized, Double-Blind, Placebo-Controlled Clinical StudyView study →}.

A valerian–hops combination produced modest, mostly non-significant improvements in self-rated sleep, with no change on polysomnography ^{13Reference 13Morin CM et al. · 2005RCTValerian-hops combination and diphenhydramine for treating insomnia: a randomized placebo-controlled clinical trialView study →}. In a later feasibility trial of 40 people, a valerian–hops product increased sleep duration measured by fitness trackers by about 22 minutes a night ^{14Reference 14Schicktanz N et al. · 2025RCTEffects of a Valerian-Hops Extract Combination (Ze 91019) on Sleep Duration and Daytime Parameters in Occasional Insomnia: A Randomized Controlled Feasibility TrialView study →}.

Gap: the benefit is confined to subjective self-report; objective sleep architecture is essentially unchanged, and heterogeneity of extract type and dose prevents a clear effective-dose recommendation.

Valerenic acid enhances GABA-induced currents only at GABA-A receptors that contain β2 or β3 subunits. It acts at a site linked to the loreclezole binding pocket, and its effect is not blocked by the benzodiazepine antagonist flumazenil ^{23Reference 23Khom S et al. · 2007Valerenic acid potentiates and inhibits GABA(A) receptors: molecular mechanism and subunit specificityView study →}.

Valerenic acid and its alcohol valerenol bind GABA-A receptors with nanomolar affinity. Both reduced anxiety-like behaviour in normal mice in the elevated plus maze and light/dark tests. In mice carrying a β3 point mutation (N265M), the effect of valerenic acid was absent ^{24Reference 24Benke D et al. · 2009AnimalGABA-A receptors as in vivo substrate for the anxiolytic action of valerenic acidView study →}.

In a separate mouse study, adding acetoxyvalerenic acid cancelled the anxiolytic effect of valerenic acid ^{25Reference 25Becker A et al. · 2014The anxiolytic effects of a Valerian extract is based on valerenic acidView study →}. In female mice, valerenic acid at 12 mg/kg reduced anxiety-like behaviour as much as diazepam, without changing movement ^{30Reference 30Pinder NE et al. · 2024AnimalValerenic acid reduces anxiety-like behavior in young adult, female (C57BL/6J) miceView study →}. Oral valerenic acid also lowered stress hormone levels and serotonin and noradrenaline turnover in the hippocampus and amygdala of stressed mice ^{31Reference 31Jung HY et al. · 2015AnimalValerenic Acid Protects Against Physical and Psychological Stress by Reducing the Turnover of Serotonin and Norepinephrine in Mouse Hippocampus-Amygdala RegionView study →}.

Human evidence is thin. A Cochrane review found one eligible trial, of 36 patients with generalised anxiety disorder, and judged the evidence insufficient ^{15Reference 15Miyasaka LS et al. · 2006Valerian for anxiety disordersView study →}. A network meta-analysis of herbal anxiolytics found insufficient evidence for valerian ^{16Reference 16Zhang W et al. · 2022Meta-analysisMedicinal herbs for the treatment of anxiety: A systematic review and network meta-analysisView study →}.

In that pilot trial, valepotriates (mean 81.3 mg/day) did not beat placebo on the main anxiety scale, though the psychic-symptom score fell ^{17Reference 17Andreatini R et al. · 2002RCTEffect of valepotriates (valerian extract) in generalized anxiety disorder: a randomized placebo-controlled pilot studyView study →}. In an EEG trial in 64 stressed volunteers, 100 mg three times daily changed frontal alpha coherence, but clinical scores improved equally on valerian and placebo ^{19Reference 19Roh D et al. · 2019RCTValerian extract alters functional brain connectivity: A randomized double-blind placebo-controlled trialView study →}.

Gap: adequately powered human anxiety RCTs are essentially absent, and the human case rests on the animal and receptor data.

In a double-blind RCT in 100 students, 255 mg of valerian three times daily for the first three days of menstruation, over two cycles, reduced pain more than placebo. The authors attributed the effect to its antispasmodic action ^{21Reference 21Mirabi P · 2011Effects of valerian on the severity and systemic manifestations of dysmenorrheaView study →}.

A 2025 systematic review pooled five controlled trials (201 intervention, 207 control participants) and found a significant reduction in pain (SMD −1.03, 95% CI −1.74 to −0.33). Heterogeneity was very high (I² = 90%), and the trials were few and small ^{22Reference 22Rabiei F et al. · 2025Meta-analysisEffect of Valeriana officinalis on Primary Dysmenorrhea: A Systematic Review and Meta-AnalysisView study →}.

Independent replication in other populations, with consistent dosing, is lacking.

In a triple-blind RCT in 60 postmenopausal women aged 45–55 in Iran, 530 mg twice daily for two months reduced hot-flash severity at one and two months and frequency at two months compared with placebo ^{20Reference 20Jenabi E et al. · 2018RCTThe effect of Valerian on the severity and frequency of hot flashes: A triple-blind randomized clinical trialView study →}.

A separate RCT in postmenopausal women with insomnia found improved sleep on the same dose but did not measure hot flashes ^{9Reference 9Taavoni S et al. · 2011RCTEffect of valerian on sleep quality in postmenopausal women: a randomized placebo-controlled clinical trialView study →}.

The trial authors describe valerian as phytoestrogenic, but that action was not tested in these trials, and no larger or multicentre trial exists.

Side effects. Adverse events in trials are generally mild and similar to placebo: headache, dizziness, stomach upset and morning grogginess. The largest review found no severe adverse events in people aged 7 to 80 ^{1Reference 1Shinjyo N et al. · 2020Meta-analysisValerian Root in Treating Sleep Problems and Associated Disorders — A Systematic Review and Meta-AnalysisView study →}. The European herbal monograph lists nausea and abdominal cramps ^{37Reference 37European Medicines Agency · 2016ReviewEuropean Union herbal monograph on Valeriana officinalis L., radixView study →}. A small number of people feel restless rather than sedated.

Other sedatives. Because valerenic acid enhances GABA-A signalling, valerian may add to the effect of alcohol, benzodiazepines, barbiturates, opioids, sedating antihistamines and other sedatives ^{23,24Reference 23Khom S et al. · 2007Valerenic acid potentiates and inhibits GABA(A) receptors: molecular mechanism and subunit specificityView study →Reference 24Benke D et al. · 2009AnimalGABA-A receptors as in vivo substrate for the anxiolytic action of valerenic acidView study →}. An Australian analysis of adverse reaction reports found that every life-threatening reaction to valerian occurred when it was taken with prescription medicines ^{33Reference 33Hoban CL et al. · 2019Analysis of spontaneous adverse drug reactions to echinacea, valerian, black cohosh and ginkgo in Australia from 2000 to 2015View study →}.

Driving. Valerian may impair the ability to drive and use machines, and people affected should not drive ^{37Reference 37European Medicines Agency · 2016ReviewEuropean Union herbal monograph on Valeriana officinalis L., radixView study →}.

Surgery. In animals, valerian extract prolonged anaesthesia with thiopental ^{34Reference 34European Medicines Agency · 2016Assessment report on Valeriana officinalis L., radix and Valeriana officinalis L., aetheroleumView study →}. Stopping valerian about a week before surgery is commonly advised.

Children. Use under 12 years of age is not recommended, as there are not enough data on safety and effectiveness ^{37Reference 37European Medicines Agency · 2016ReviewEuropean Union herbal monograph on Valeriana officinalis L., radixView study →}.

Overdose. About 20 g of root caused fatigue, abdominal cramps, chest tightness, light-headedness, hand tremor and dilated pupils, which resolved within 24 hours ^{37Reference 37European Medicines Agency · 2016ReviewEuropean Union herbal monograph on Valeriana officinalis L., radixView study →}.

Drug metabolism. No drug interactions are reported in the European monograph ^{37Reference 37European Medicines Agency · 2016ReviewEuropean Union herbal monograph on Valeriana officinalis L., radixView study →}. In healthy volunteers, valerian taken for 28 days did not change CYP1A2, CYP2D6, CYP2E1 or CYP3A4 activity ^{40Reference 40Gurley BJ et al. · 2005AnimalIn vivo effects of goldenseal, kava kava, black cohosh, and valerian on human cytochrome P450 1A2, 2D6, 2E1, and 3A4/5 phenotypesView study →}.

In a second volunteer study, 1,000 mg nightly for 14 days left CYP2D6 unchanged and raised alprazolam’s peak level slightly without changing overall exposure, an effect too small to matter clinically ^{41Reference 41Donovan JL et al. · 2004Multiple night-time doses of valerian (Valeriana officinalis) had minimal effects on CYP3A4 activity and no effect on CYP2D6 activity in healthy volunteersView study →}.