Index of Herbs

Monograph

Valerian

Valeriana officinalis

Updated October 4, 2026

Valerian (Valeriana officinalis) standing tall at a damp meadow edge at dusk, domed clusters of tiny white-pink flowers above divided leaves, painted in oils, with a parchment botanical inset of the knotted root and rhizome

Key points

  1. 01

    Mixed sleep evidence

    People often report better sleep on valerian, but objective measures such as time to fall asleep barely change. Rigorous trials are mostly negative.

  2. 02

    Europe and the AASM disagree

    EMA accepts specific ethanol extracts for mild nervous tension and sleep disorders. The US sleep academy’s 2017 guideline suggests clinicians not use it.

  3. 03

    Slow, not a sleeping pill

    EMA says the effect builds gradually and recommends two to four weeks of use. It is not suitable for occasional, same-night use.

  4. 04

    Valerenic acid and GABA-A

    Valerenic acid enhances GABA-A receptors containing β2 or β3 subunits in lab and mouse studies. Product content varies widely.

  5. 05

    Grogginess, withdrawal, rare liver injury

    It may impair next-day driving, abrupt stopping after long use can cause withdrawal, and rare liver injury is reported, mostly with combination products.

Valerian is the classic herbal sleeping pill, and it smells like it is trying to tell you something. The dried root of Valeriana officinalis gives off a sharp, sweaty, old-cheese odour that many people find hard to tolerate, which is why most of it is sold in coated tablets. In Europe it is a registered medicine. The EU’s herbal committee accepts specific ethanol extracts for the relief of mild nervous tension and sleep disorders on the basis of clinical studies, a stronger status than most sleep herbs get. In the United States it is a dietary supplement, and the American Academy of Sleep Medicine’s 2017 guideline suggests clinicians not use it for chronic insomnia.

Both positions rest on the same muddled literature. Dozens of trials have tested different extracts, doses, durations, and outcomes. Meta-analyses that count how many people felt they slept better tend to favour valerian. Meta-analyses that measure how long it takes to fall asleep, or record sleep in a laboratory, tend to find nothing. NCCIH’s May 2025 summary calls the evidence inconsistent and says there is not enough to determine whether valerian is useful for any health condition. Shinjyo’s 2020 review argues the inconsistency may come from variable product quality. Taibi’s 2007 review summed it up in its title: safe but not effective.

This monograph lays out what is known. Valerian is generally safe for short-term use by most adults, causes mild side effects, and may cause withdrawal symptoms if stopped abruptly after long use. Rare liver injury has been reported, usually with combination products. Chronic insomnia has a first-line treatment that works better than any pill, cognitive behavioural therapy for insomnia (CBT-I). Snoring with daytime sleepiness, or sleeplessness with low mood, needs assessment. Nothing here is medical advice.

In this monograph

01 The plant

Botanical profile

Valeriana officinalis L. is a tall perennial of damp meadows, stream banks, and woodland edges. Older floras put it in its own family, Valerianaceae; current classifications fold that family into Caprifoliaceae, the honeysuckle family. NCBI Taxonomy files it as taxon 19953. It grows from a short, upright rhizome with many fine roots into flowering stems often over a metre tall, with paired leaves divided into narrow toothed leaflets. In early summer it carries rounded clusters of tiny white to pale pink flowers that smell sweet, the opposite of the root. NCCIH describes it as native to Europe and Asia and growing in North America, where it has naturalized. Its common names include all-heal and garden heliotrope.

The medicinal part is the root and rhizome, dug in autumn, washed, and dried at low temperature. The smell develops on drying, as valerian’s esters break down and release isovaleric acid (PubChem CID 10430, C5H10O2), the same short-chain fatty acid responsible for much of the odour of sweaty feet. Fresh root smells much milder. Several related species are used in traditional medicine and sold under the valerian name: V. jatamansi (syn. V. wallichii), Indian valerian, in Ayurveda; V. fauriei in Japan; and V. edulis, Mexican valerian. Their chemistry differs, especially in sesquiterpenes, and the EU monograph and most trials concern V. officinalis only.

Three groups of compounds get most of the attention. Valerenic acid (CID 6440940, C15H22O2) and its acetoxy and hydroxy derivatives are sesquiterpenes characteristic of V. officinalis and are the usual markers for standardizing extracts. Valepotriates such as valtrate and didrovaltrate are unstable iridoid esters that break down during drying, storage, and extraction, so their content in a finished product is unpredictable. The essential oil, rich in bornyl acetate and other terpenes, carries part of the aroma. Lignans, flavonoids, and free amino acids including GABA and glutamine are also present. EMA notes that the sleep effects cannot be attributed with certainty to any known constituent, which is one reason extracts differ in clinical results.

Cats notice valerian too. In a 2017 study by Bol and colleagues, about half of 100 domestic cats responded to dried valerian root with the rolling and rubbing usually associated with catnip, a response to volatile compounds in the root. That is a reason to keep valerian products closed and away from pets, not evidence of sedation.

02 Lineage

History

NCCIH notes that valerian has been used medicinally since early Greek and Roman times, historically for insomnia, migraine, fatigue, and stomach cramps. Classical writers described a plant called phu, a name usually read as a comment on the smell, and later commentators identified it with valerian. The Latin name valeriana appears in the Middle Ages and is usually traced to valere, to be strong or healthy, though some derive it from a place or personal name. Its English folk name all-heal reflects how widely it was used. By the early modern period valerian was a standard European nervine, given for nervous complaints, palpitations, hysteria, and epilepsy as well as sleeplessness.

Valerian moved from herbal to pharmacy shelf in the nineteenth and twentieth centuries. It appeared in national pharmacopoeias, valerian tinctures and teas were common household sedatives, and German health authorities later accepted valerian root for restlessness and nervous sleep disturbances. The EU’s Committee on Herbal Medicinal Products adopted its first valerian monograph in July 2006 and a revised monograph on 2 February 2016. That revision recognizes specified dry ethanol extracts as well-established use for mild nervous tension and sleep disorders and keeps teas, tinctures, and other preparations under traditional use.

The modern evidence record is a series of reversals. Early small trials, many from Europe, were encouraging. Larger and more rigorous trials from the 2000s, including a US National Cancer Institute–sponsored trial in people with cancer, mostly were not. Systematic reviews in 2006, 2007, 2010, 2015, and 2020 reached conclusions ranging from might improve sleep quality to safe but not effective. In 2017 the American Academy of Sleep Medicine included valerian in its insomnia guideline and suggested clinicians not use it. Valerian is still sold widely on both sides of the Atlantic.

03 Chemistry

Active compounds and how it works

The leading mechanism involves GABA-A receptors, the target of benzodiazepines and Z-drugs, but at a different site. Benke and colleagues (Neuropharmacology 2009) found that valerenic acid and valerenol bind GABA-A receptors with nanomolar affinity and enhance responses to GABA in receptors containing β2 or β3 subunits. In mice, valerenic acid reduced anxiety-like behaviour in standard tests, and the effect disappeared in mice carrying a single point mutation (N265M) in the β3 subunit. That is strong evidence that valerenic acid acts on a specific receptor, at least in rodents. MSKCC’s summary adds that valerenic acid may inhibit GABA breakdown and that valerian constituents bind serotonin and other receptors involved in sleep and anxiety.

The gap is between molecule and bedside. Valerenic acid content varies widely between products, valepotriates degrade, and the amounts reaching the human brain from a standard dose are not well characterized. EMA’s monograph says the clinical effects on sleep latency and sleep quality cannot be attributed with certainty to any known constituent, and it notes a gradual onset: valerian is not suitable for acute treatment, and the recommended course is two to four weeks of continued use. Some early studies reported impaired information processing or vigilance one to two hours after a single dose (MSKCC), which supports a real central effect while also supporting the driving warnings. MSKCC also notes that valerian iridoids have choleretic activity, a possible link to gallbladder and pancreatic cautions.

04 In practice

Common uses

Insomnia is the main use and the main disagreement. Bent and colleagues (American Journal of Medicine 2006) reviewed 16 placebo-controlled trials with 1,093 patients. Most had significant methodological problems, and doses, preparations, and durations varied. In the six studies with a yes-or-no sleep quality outcome, valerian roughly doubled the chance of reporting improved sleep (relative risk 1.8), but there was evidence of publication bias. Taibi and colleagues (Sleep Medicine Reviews 2007) examined 29 controlled trials and found most showed no difference from placebo, and that none of the most recent and rigorous trials found significant effects. Fernández-San-Martín and colleagues (Sleep Medicine 2010) pooled 18 trials: valerian improved subjective sleep quality (relative risk 1.37) but changed time to fall asleep by less than a minute (0.70 minutes; interval −3.44 to 4.83) and did not improve sleep quality scales.

Later work did not resolve it. Leach and Page (Sleep Medicine Reviews 2015) reviewed 14 trials of herbal monotherapies for insomnia with 1,602 participants and found no significant difference between any herb, including valerian, and placebo on any of 13 efficacy measures; valerian trials recorded more adverse events per person than placebo. The NCI-sponsored N01C5 trial (Barton, Journal of Supportive Oncology 2011) randomized 227 people undergoing cancer treatment to 450 mg of valerian or placebo an hour before bed for eight weeks; among the 119 evaluable for the primary end point, sleep scores did not differ (Pittsburgh Sleep Quality Index AUC 51.4 versus 49.7), although exploratory analyses favoured valerian for fatigue. Shinjyo and colleagues (2020) reviewed 60 studies with 6,894 participants and concluded valerian could be safe and effective, attributing inconsistent results to variable extract quality and suggesting whole root or rhizome preparations give more reliable effects. That is a more favourable reading, and the authors are explicit that standardization needs to improve.

Guidelines follow the stricter reading. The American Academy of Sleep Medicine’s 2017 guideline (Sateia and colleagues) suggests clinicians not use valerian for chronic insomnia in adults; NCCIH cites that recommendation and calls the evidence inconsistent. EMA, using a different standard, accepts specified ethanol extracts for mild nervous tension and sleep disorders, noting that the effect builds over two to four weeks. In practice: some people report sleeping better on valerian, objective sleep measures rarely move, and the effect, if present, is modest and slow.

Other uses are preliminary. NCCIH reports three small studies suggesting help with menopausal symptoms and says the evidence is insufficient for anxiety, depression, premenstrual syndrome, menstrual cramps, stress, or other conditions. MSKCC lists small studies on hot flashes, dysmenorrhea, obsessive-compulsive symptoms, and supervised benzodiazepine withdrawal, all too small for firm conclusions, and reviews it cites judged the anxiety evidence insufficient. Anticancer activity of valerian compounds exists only in cells and animals. Valerian is not a treatment for sleep apnoea, restless legs, or depression, all of which commonly present as poor sleep.

05 The apothecary

Preparations and traditional use

EU well-established use (EMA/HMPC/150848/2015, adopted 2 February 2016): dry extract of valerian root made with 40–70% ethanol (DER 3–7.4:1), 400–600 mg per dose. For mild nervous tension, up to three times daily. For sleep disorders, one dose half an hour to an hour before bedtime, with an earlier dose in the evening if necessary, to a maximum of four doses daily. Because the effect is gradual, continued use over two to four weeks is recommended; if symptoms persist or worsen after two weeks, see a doctor or pharmacist. Not recommended under 12 years.

EU traditional use covers the dried root as tea or powder, fresh-root juice, aqueous and alcoholic extracts, tinctures, and a bath additive, for mild symptoms of mental stress and to aid sleep. Tea: 0.3–3 g of dried, cut root in 150 ml of boiling water, up to three times daily for stress, or once half an hour to an hour before bed. Bath: 100 g of root per full bath at 34–37 °C for 10–20 minutes, up to once daily; full baths are contraindicated with open wounds, large skin injuries, acute skin disease, high fever, severe infection, severe circulatory disturbance, or heart failure. Tinctures carry ethanol labelling.

NCCIH notes apparently safe use at 300–600 mg daily for up to six weeks; the safety of long-term use is unknown. Many US products combine valerian with hops, lemon balm, passionflower, chamomile, melatonin, or kava. Combinations make it harder to attribute either benefit or harm, and several liver injury reports involve multi-ingredient products. A product labelled only valerian 500 mg has not said whether that is dried root or an extract, or what solvent and ratio were used, and those details are what separate an EU-registered medicine from a generic capsule.

Safety

Before you use valerian

06 Caution

Side effects

Most side effects are mild. EMA lists gastrointestinal symptoms such as nausea and abdominal cramps. NCCIH adds headache, stomach upset, mental dullness, excitability, uneasiness, and vivid dreams. MSKCC lists bitter taste, daytime drowsiness or dullness, impaired alertness, dizziness, irritability, sweating, palpitations, diarrhoea, and depression as occasional or possibly related effects, and cites an analysis judging most adverse effects mild to moderate. Morning grogginess is the practical problem: valerian may impair the ability to drive or operate machinery (EMA), and anyone affected should not drive.

Withdrawal: NCCIH notes that stopping abruptly after chronic use may cause anxiety, irritability, heart disturbances, insomnia, and in rare cases hallucinations. Garges and colleagues (JAMA 1998) described cardiac complications and delirium associated with valerian root withdrawal, and MSKCC cites a case of delirium in an older man with cognitive impairment attributed to withdrawal. Taper after regular use rather than stopping suddenly, especially before surgery or hospital admission, and tell the care team about it.

Liver: NCCIH says liver injury has been reported in very rare cases, most often with other herbs in the same product, and that valerian’s long-term effect on the liver is unknown. MSKCC cites two case reports of hepatotoxicity in women that resolved after stopping, Cohen and Del Toro (Journal of Clinical Gastroenterology 2008) reported another valerian-associated case, and MSKCC also cites a case-control study linking valerian use to idiopathic acute pancreatitis. Stop and get liver tests if you develop dark urine, yellow skin or eyes, pale stools, persistent nausea, or right-sided abdominal pain.

Overdose: EMA records that about 20 g of valerian root caused fatigue, abdominal cramps, chest tightness, light-headedness, hand tremor, and dilated pupils, which resolved within 24 hours with supportive care. MSKCC also notes a case-control study that found valerian positively associated with early-onset colorectal cancer; that is an unexplained association, not evidence of cause, and no trials have tested it.

07 Caution

Contraindications

Do not use with known hypersensitivity to valerian (EMA). MSKCC advises people with liver or pancreatic disease to avoid valerian because of hepatotoxicity case reports and a possible link between valerian iridoids and acute pancreatitis, and lists gallbladder disease as a caution because of the iridoids’ choleretic effect. Do not use valerian with alcohol (NCCIH). Do not drive, cycle, or operate machinery until you know how valerian affects you the next morning.

Pregnancy and breastfeeding: EMA says safety has not been established and use is not recommended; NCCIH says little is known; MSKCC advises avoiding valerian, citing animal studies with adverse effects on fetal brain development. Reproductive toxicity and carcinogenicity tests have not been performed (EMA). Children: EMA does not recommend use under 12 because of a lack of data; in children and teenagers, persistent sleep problems need a paediatric assessment, not a sedative.

Surgery: MSKCC advises stopping valerian at least a week before surgery because it may interact with anaesthesia, and abrupt withdrawal after long use can cause problems of its own, so plan a taper with the surgical team. Insomnia that lasts more than a few weeks, loud snoring with daytime sleepiness, sleeplessness with low mood or anxiety, and sleep problems in older adults with falls or confusion all need medical assessment rather than an over-the-counter sedative.

08 Caution

Drug and herb interactions

EMA lists no reported interactions for valerian root medicines. That reflects the case record for registered products, not proof of safety in every combination. The most plausible risk is additive sedation. MSKCC advises against combining valerian with barbiturates, benzodiazepines, or other central nervous system drugs used for anxiety, insomnia, seizures, or psychiatric disorders, because valerian prolonged sedation in animal studies and a case report and an animal study suggest synergy with benzodiazepines. The same logic applies to Z-drugs, opioids, gabapentinoids, sedating antihistamines, alcohol, and other sedating herbs such as kava, hops, and passionflower.

Metabolism: MSKCC notes that valerian inhibited CYP2D6 and CYP3A4 and P-glycoprotein in some laboratory studies, while studies in living systems and in people suggest clinically important CYP-mediated interactions are unlikely. MSKCC also lists haloperidol, based on an animal study suggesting additive liver damage of unknown clinical relevance, and UGT-metabolized drugs, based on preclinical data. Compared with St. John’s wort, valerian’s pharmacokinetic interaction risk appears low.

Do not use valerian to replace or taper off a benzodiazepine or Z-drug without a prescriber’s plan. Benzodiazepine withdrawal can cause seizures, and a herbal sedative does not cover that risk. Tell the anaesthetist and every prescriber about valerian, including in combination sleep products. If you take a sleep product with several herbs, check each ingredient for its own interactions.

09 Questions

Frequently Asked Questions

Possibly a little, for some people, and the evidence is inconsistent. Meta-analyses find people more likely to report better sleep on valerian, but time to fall asleep and laboratory sleep measures barely change, and the most rigorous trials are mostly negative. The American Academy of Sleep Medicine suggests clinicians not use it for chronic insomnia. CBT-I is the first-line treatment and works better than any supplement. Other bedtime herbs such as chamomile and lavender have their own, similarly limited, sleep evidence.

EMA says the effect is gradual and recommends continued use over two to four weeks for the best result; it is not suitable for acute, same-night treatment. If sleep problems persist or worsen after two weeks, see a doctor or pharmacist.

As the root dries, compounds break down and release isovaleric acid, the same molecule behind much of the smell of sweaty feet. Fresh root and the flowers smell much milder. Coated tablets are a practical way around the smell. Cats are often attracted to it, so store it closed.

Avoid it. NCCIH says valerian should not be taken with alcohol or sedatives, and MSKCC warns it may lengthen and intensify sedation from benzodiazepines, barbiturates, and other CNS drugs. Never use valerian to replace a benzodiazepine without a prescriber’s taper plan, because benzodiazepine withdrawal can cause seizures.

It is not considered addictive in the way benzodiazepines are, but withdrawal symptoms, including anxiety, irritability, heart disturbances, insomnia, and rarely hallucinations or delirium, have been reported when people stop abruptly after long, regular use. Taper gradually, and tell your care team before surgery.

For most short-term users, liver problems appear rare. NCCIH notes very rare liver injury reports, mostly with combination herbal products, and the long-term effect on the liver is unknown. People with liver, pancreatic, or gallbladder disease should avoid it. Stop and seek care if you notice yellow skin or eyes, dark urine, or pale stools.

EMA does not recommend valerian in pregnancy or breastfeeding because safety has not been established, and MSKCC cites animal data on fetal brain development. EMA also does not recommend it under 12 years. Sleep problems in pregnancy or childhood are worth raising with a doctor.

10 References

Sources

These references support the history, clinical, and safety claims on this page. They are not an endorsement of any product.

  1. Valerian

    National Center for Complementary and Integrative Health (NIH), 2025

    Consumer evidence summary (updated May 2025): inconsistent sleep evidence; AASM 2017 recommended against for chronic insomnia; 300–600 mg up to six weeks apparently safe; withdrawal symptoms; very rare liver injury.

  2. Valerian

    Memorial Sloan Kettering Cancer Center, About Herbs, 2023

    Clinical summary (updated November 2023): mixed sleep data; valerenic acid and GABA; stop a week before surgery; withdrawal; hepatotoxicity and pancreatitis cautions; CNS-depressant interactions.

  3. European Union herbal monograph on Valeriana officinalis L., radix

    European Medicines Agency (EMA/HMPC/150848/2015), 2016

    Adopted 2 February 2016: well-established use of 40–70% ethanol extract (400–600 mg) for mild nervous tension and sleep disorders; two to four weeks for effect; traditional tea and bath; not under 12; may impair driving.

  4. Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults

    Journal of Clinical Sleep Medicine, American Academy of Sleep Medicine (PubMed 27998379), 2017

    Sateia et al.: GRADE-based guideline; suggests clinicians not use valerian for sleep onset or sleep maintenance insomnia.

  5. Valerian for sleep: a systematic review and meta-analysis

    American Journal of Medicine (PubMed 17145239), 2006

    Bent et al.: 16 trials, 1,093 patients; RR 1.8 for improved sleep in six studies with evidence of publication bias; significant methodological problems.

  6. A systematic review of valerian as a sleep aid: safe but not effective

    Sleep Medicine Reviews (PubMed 17517355), 2007

    Taibi et al.: 29 controlled trials; most found no difference from placebo; the most rigorous recent trials were negative; rare adverse events.

  7. Effectiveness of valerian on insomnia: a meta-analysis of randomized placebo-controlled trials

    Sleep Medicine (PubMed 20347389), 2010

    Fernández-San-Martín et al.: 18 trials; subjective improvement RR 1.37; sleep latency difference 0.70 minutes; no change on sleep quality scales.

  8. Herbal medicine for insomnia: a systematic review and meta-analysis

    Sleep Medicine Reviews (PubMed 25644982), 2015

    Leach and Page: 14 trials, 1,602 participants; no herb beat placebo on any of 13 measures; more adverse events per person with valerian.

  9. Valerian root in treating sleep problems and associated disorders: a systematic review and meta-analysis

    Journal of Evidence-Based Integrative Medicine (PubMed 33086877), 2020

    Shinjyo et al.: 60 studies, 6,894 participants; attributes inconsistency to extract quality; no severe adverse events in ages 7–80.

  10. The use of Valeriana officinalis (valerian) in improving sleep in patients undergoing treatment for cancer (NCCTG N01C5)

    Journal of Supportive Oncology (PubMed 21399726), 2011

    Barton et al.: 227 randomized; 450 mg at bedtime for eight weeks; no difference in sleep quality (PSQI); exploratory fatigue benefit.

  11. GABA-A receptors as in vivo substrate for the anxiolytic action of valerenic acid, a major constituent of valerian root extracts

    Neuropharmacology (PubMed 18602406), 2009

    Benke et al.: valerenic acid and valerenol bind GABA-A receptors with β2/β3 subunits; anxiolytic effect absent in β3 N265M mutant mice.

  12. Cardiac complications and delirium associated with valerian root withdrawal

    JAMA (PubMed 9820254), 1998

    Garges, Varia, and Doraiswamy: case report linking abrupt cessation of long-term valerian root use to cardiac complications and delirium.

  13. Responsiveness of cats (Felidae) to silver vine, Tatarian honeysuckle, valerian, and catnip

    BMC Veterinary Research (PubMed 28302120), 2017

    Bol et al.: about half of 100 domestic cats responded to valerian root.

  14. Valerenic acid

    PubChem, National Library of Medicine (NIH), 2026

    Sesquiterpene marker of Valeriana officinalis; CID 6440940, C15H22O2.