At a glance: Valerian is the root and rhizome of Valeriana officinalis L. and is one of Europe’s best-known traditional sleep herbs. Its evidence is unusually instructive: the EMA recognises well-established use for a specific dry ethanolic root extract in mild nervous tension and sleep disorders, while other valerian preparations remain in the traditional-use category. Independent systematic reviews have reached mixed conclusions about insomnia.[1][2][3]
Botanical profile
- Accepted name: Valeriana officinalis L.
- Common name: valerian.
- Family: Caprifoliaceae (older texts may place it in Valerianaceae).
- Medicinal part: dried underground parts, principally root and rhizome.
- EMA herbal drug name: Valerianae radix.[1]
Major constituent groups
Valerian has complex and variable chemistry. Important groups include:
- Sesquiterpenes, especially valerenic acid and related compounds.
- Iridoid esters / valepotriates, such as valtrate and didrovaltrate, particularly discussed in fresh or less processed material.
- Volatile oil constituents, including bornyl derivatives and other monoterpenes and sesquiterpenes.
- Flavonoids, lignans and minor alkaloids reported in the root.[4]
Valerenic acid is commonly used as a phytochemical marker in standardised extracts, but it should not be treated as the sole “active ingredient” of valerian.
Traditional use
Valerian has been used in European herbal medicine for nervous tension, restlessness, difficulty settling to sleep and states of nervous exhaustion. It has also traditionally been used where digestive or muscular tension appeared to worsen during periods of stress.
Contemporary herbal practice
Valerian is commonly used by Western herbalists when nervous tension presents with physical restlessness, muscular tension or difficulty settling into sleep. It is frequently combined with herbs such as passionflower, hops, lemon balm or skullcap rather than used as a universal standalone sedative. Practitioners also recognise marked individual variation: a minority of people find valerian surprisingly stimulating, which is one reason clinical herbal practice pays attention to the person as well as the pharmacological category.
EMA: preparation-specific evidence
The EMA HMPC distinguishes a specific dry ethanolic valerian-root extract from other preparations. The dry ethanolic extract has well-established use for relief of mild nervous tension and sleep disorders, based on documented medicinal use and supporting clinical studies. Other preparations—including certain teas, tinctures, juices and extracts—are classified for traditional use to relieve mild mental stress and aid sleep.[1]
This distinction is one of the clearest examples of why students must record the extraction method when describing herbal evidence.
What do systematic reviews say about sleep?
The broader trial literature is mixed. A 2006 systematic review found a possible subjective improvement in sleep quality but substantial methodological problems, variation in preparations and evidence of publication bias.[2] A later 2020 systematic review and meta-analysis also found heterogeneous results and suggested that differences in extract quality may partly explain inconsistency.[3]
NCCIH currently describes the evidence for valerian in sleep problems as inconsistent and notes that there is not enough evidence to determine usefulness for health conditions with confidence.[5]
Those statements can coexist with the EMA’s well-established-use classification because the EMA conclusion applies to specified preparations and regulatory criteria rather than to every valerian product sold commercially.
Onset and “take it once” expectations
The EMA monograph notes that valerian’s onset is gradual and that it is not suited to acute, one-off intervention for mild nervous tension or sleep disorders in the same way as a rapidly acting sedative medicine.[1] That point is useful when comparing traditional expectations with trial design: a study testing only a single dose may be asking a different question from a study of repeated use.
Pharmacology
Valerenic acid and related constituents have been investigated for modulation of GABAA receptors and other neurotransmitter systems. Experimental research provides plausible mechanisms for sedative or anxiolytic effects, but the pharmacology is not completely resolved and mechanistic evidence does not replace clinical trials.[4]
Preparations
Regulatory literature describes comminuted or powdered dried root, fresh-root juice, dry extracts and liquid extracts. Valerian essential oil is assessed separately by the EMA and has traditional-use status for mild mental stress and aiding sleep.[6]
Safety
Reported adverse effects include nausea and abdominal cramps. NCCIH also notes headache, stomach upset, mental dullness, excitability, uneasiness and vivid dreams in some users, while long-term safety remains insufficiently characterised.[1][5]
Because valerian may cause drowsiness, the EMA cautions about driving and operating machinery when using valerian-root medicines.[1]
Interactions
The EMA assessment reported no described medicine interactions in the literature at the time of assessment for valerian root.[1] That does not mean pharmacodynamic combinations with sedating medicines are automatically irrelevant; where multiple sedating agents are used, additive effects remain a sensible clinical consideration even if formal interaction evidence is limited.
Pregnancy, breastfeeding and children
The EMA public summary states that valerian-root medicines should not be used during pregnancy or breastfeeding and are not recommended for children under 12 years in the assessed medicinal context.[1]
Student note: common evidence traps
- Do not write “valerian is proven for insomnia” without naming the preparation and evidence source.
- Do not assume a tea and a dry ethanolic extract have the same evidence status.
- Do not turn GABA-receptor findings into proof of clinical anxiolysis.
- Record whether a study measured subjective sleep quality, objective sleep parameters, or both.
- Mixed meta-analytic findings are not a reason to hide the EMA classification; they are a reason to explain preparation specificity.
References
- European Medicines Agency, Committee on Herbal Medicinal Products. Valerianae radix — Valeriana officinalis L., radix. EU herbal monograph, list entry and assessment report. EMA. Revision published 2016; periodic review call 2025.
- Bent S, Padula A, Moore D, Patterson M, Mehling W. Valerian for sleep: a systematic review and meta-analysis. American Journal of Medicine. 2006;119(12):1005–1012. doi:10.1016/j.amjmed.2006.02.026. PubMed.
- Shinjyo N, Waddell G, Green J. Valerian root in treating sleep problems and associated disorders—A systematic review and meta-analysis. Journal of Evidence-Based Integrative Medicine. 2020;25:2515690X20967323. doi:10.1177/2515690X20967323. PubMed.
- Orhan IE. A review focused on molecular mechanisms of anxiolytic effect of Valeriana officinalis L. in connection with its phytochemistry through in vitro/in vivo studies. Current Pharmaceutical Design. 2021;27(28):3084–3090. doi:10.2174/1381612827666210119105254. PubMed.
- National Center for Complementary and Integrative Health. Valerian: Usefulness and Safety. NCCIH. Consulted September 2026.
- European Medicines Agency, Committee on Herbal Medicinal Products. Valerianae aetheroleum — Valeriana officinalis L., aetheroleum. EU herbal monograph and assessment report. EMA. Published 2016.
Additional materia medica sources
- ESCOP. Valerianae radix — Valerian root, ESCOP Monographs.
- Blumenthal M, et al., eds. The Complete German Commission E Monographs. American Botanical Council; 1998.
- British Herbal Medicine Association. British Herbal Compendium, Volume 1 — Valerian Root.
- Hoffmann D. Medical Herbalism. Healing Arts Press; 2003.
Last reviewed: 20 September 2026. Educational reference only; not an individual dosing or prescribing guide.
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