Europe recognizes valerian as medicine, and it still carries a driving warning

Key takeaways

• Galen prescribed valerian for insomnia in the second century, and people in England used it to cope with the stress of air raids during World War II¹.
• The European Medicines Agency accepts an alcohol-based valerian root extract for mild nervous tension and sleep problems, yet its public summary tells users not to drive or operate machinery⁴⁵.
• A Cochrane review found only one small trial of valerian for anxiety disorders, with 36 patients, and valerian did no better than a placebo⁶.
• In a 1999 trial with 102 volunteers, 600 milligrams of a valerian extract taken in the evening didn’t slow reaction times the next morning⁷.
• Stopping valerian suddenly after long use can bring anxiety, irritability, heart disturbances and insomnia, NCCIH warns, so don’t quit cold after months of daily use².

During World War II, people in England took valerian root to ease the stress of air raids, according to the NIH Office of Dietary Supplements (ODS)¹.

By then the plant already had a long record. Hippocrates described its uses, and the physician Galen prescribed it for insomnia in the second century¹.

Valerian has also passed a test many herbs never pass. In the European Union, a valerian root extract is recognized as a medicine for mild nervous tension and sleep problems, based on clinical studies⁴.

Yet Europe’s summary for patients says not to drive or operate machinery while using it, and the official monograph warns that it may impair driving⁴⁵. And in the U.S., the National Center for Complementary and Integrative Health (NCCIH) says there isn’t enough evidence to know whether valerian helps any health condition².

Both things can be true at once. Our sleep-aid scorecard covered valerian’s sleep trials. This profile covers the rest: its history, its European status, its record for anxiety, the next-morning question, its blends with hops and lemon balm, and its rare but real risks.

A pungent root that Greek and Roman doctors knew

Valerian is Valeriana officinalis, a perennial that first grew wild across Europe and Asia and has since taken hold in North America¹. Common names include all-heal and garden heliotrope², and ODS lists “phu” as its Greek name¹.

The medicine comes from below ground: the roots, the rhizomes (underground stems) and the stolons (horizontal runners)¹. It’s sold as tea, tincture, capsules and tablets¹. In Europe it also comes as a bath additive⁴, and LiverTox notes it turns up in many relaxation drinks³.

The smell. Valerian has a strong odor that many people find unpleasant¹. One clinical newsletter compared it to smelly socks⁸. The culprit is isovaleric acid, which forms as unstable compounds called valepotriates break down⁸. So a strong smell is expected.

The chemistry. The root contains a volatile oil that includes valerenic acid, along with sesquiterpenes and valepotriates¹. Scientists haven’t agreed on which compound does the work, and several may act together¹. One theory involves GABA, the brain’s main calming messenger¹.

Its uses have shifted over the centuries. Older European herbal medicine used valerian mainly for digestive and urinary complaints, LiverTox says³. In the 1500s it was taken for nervousness, trembling, headaches and heart palpitations¹. By the mid-1800s it was seen as a stimulant that could cause some of those same complaints¹. Today it’s sold mostly for sleep, stress and anxiety²³.

Europe’s official verdict comes in two tiers

The European Medicines Agency’s herbal committee publishes official monographs, summaries of what’s known about an herbal medicine’s use and safety⁴. Valerian root’s current monograph is a revision adopted in February 2016⁵. The committee has started a periodic review. Its call for new scientific data closed in May 2025, and as of October 2026 the agency’s page listed no newer version⁴.

The monograph sorts valerian products into two tiers⁴:

• Well-established use. A dry extract of the root made with ethanol, for relief of mild nervous tension and sleep problems. This tier rests on published clinical studies and at least 10 years of medical use in the EU.
• Traditional use. Teas, juice, tinctures and other extracts, for mild symptoms of mental stress and to aid sleep. This tier rests on at least 30 years of safe use, 15 of them in the EU, rather than on trials.

The monograph spells out the details⁵. For sleep, it lists one dose of 400 to 600 milligrams of that dry extract, taken half an hour to an hour before bed, with an earlier evening dose if needed⁵. For tea, it lists 0.3 to 3 grams of cut root in 150 milliliters, about two-thirds of a cup, of boiling water⁵.

It also says valerian works gradually, so it isn’t suited to quick relief. It recommends steady use for 2 to 4 weeks, and seeing a doctor or pharmacist if symptoms continue or get worse after 2 weeks⁵.

Europe’s summary for the public adds firm limits⁴:

• no use in children under 12;
• no use during pregnancy or breastfeeding;
• no driving or operating machinery, since valerian may affect that ability;
• possible side effects of nausea and stomach cramps.

In the U.S., valerian is a dietary supplement. It needs no FDA approval before sale, and its makeup may vary from batch to batch¹². Europe is still adding guardrails: a Dutch draft rule, under EU review in October 2026, would require warning statements on supplements containing valerian and several other herbs¹⁴.

This is what respect for an herbal tradition can look like. Europe kept valerian on pharmacy shelves, but wrote down which part, which preparation, which dose and for how long.

For anxiety, Cochrane found one small trial

Valerian is widely sold for worry and nerves. The research is thin.

In 2006, Cochrane reviewers looked for trials of valerian for anxiety disorders⁶. They turned up just one: a four-week pilot study of 36 people with generalized anxiety disorder⁶. It pitted valerian against a placebo and against diazepam, a prescription anti-anxiety drug⁶.

On the doctor-rated anxiety scale, valerian did no better than placebo⁶. It also landed about even with diazepam on that scale, though a second, self-rated anxiety measure favored diazepam⁶. Side effects and dropouts were similar in all three groups⁶. With a single small study, the reviewers said, no one could tell whether valerian works or is safe for anxiety disorders⁶.

Two decades later, NCCIH still says there isn’t enough evidence to draw conclusions about valerian for anxiety².

A newer trial hints at a short-lived effect. In a study published in 2017 and funded by the American University of Madaba in Jordan, war refugees took one dose of 320 milligrams of valerian root extract with 80 milligrams of hops, an antihistamine or a placebo⁹. An hour later, the valerian-hops group reported less anxiety than the placebo group⁹. But their sleep quality was similar to placebo, and total sleep time didn’t differ among the groups⁹.

For hot flashes in menopause, NCCIH says three small studies suggest a possible benefit, though the evidence isn’t strong enough to be sure².

The morning after: reaction-time tests found no hangover

A common worry with any sleep aid is feeling foggy the next day. Valerian has been tested on that point.

In a trial published in 1999 in the journal Pharmacopsychiatry, 102 volunteers took 600 milligrams of a valerian root extract called LI 156 in the evening⁷. After a single dose, valerian didn’t impair reaction time, concentration or coordination the next morning⁷. That part of the study also included flunitrazepam, a strong prescription sedative, for comparison⁷. After 14 evenings in a row, reaction times on valerian matched those on placebo⁷.

One small study did note morning sleepiness after a higher dose of 900 milligrams, ODS reports¹.

Europe still warns that valerian may impair driving⁴⁵. One trial can’t rule out effects in every person at every dose. The practical step is to try valerian first on a night before a day when you don’t need to drive.

Too much can make you sick. The EU monograph notes that about 20 grams of root caused tiredness, stomach cramps, chest tightness, lightheadedness, hand tremor and enlarged pupils, which cleared within a day⁵.

Hops, lemon balm and the blend question

Valerian is often sold in blends. Only a few combinations have been tested.

Valerian and hops. In a 1982 study of 128 volunteers, a 400-milligram water extract of valerian improved how people rated their sleep compared with placebo, ODS reports¹. A commercial product with just 60 milligrams of valerian and 30 milligrams of hops didn’t¹. The lesson: a blend can hold too little of each herb to matter.

A larger trial, published in the journal Sleep in 2005, tested a stronger valerian-hops tablet against the antihistamine diphenhydramine and a placebo¹². For four weeks, 184 adults with occasional insomnia took two tablets a night, each with 187 milligrams of valerian extract and about 42 milligrams of hops extract¹².

The blend did no better than placebo on time to fall asleep, total sleep or sleep efficiency, the share of time in bed spent asleep, and overnight sleep-lab tests showed no clear change¹². Two tablets held about 374 milligrams of valerian, below the EU’s single dose of 400 to 600 milligrams⁵. A 2015 review supported by the drugmaker Pfizer also flagged the low dose¹².

Valerian and lemon balm. A 2014 summary in the Swiss medical journal Ars Medici describes a placebo-controlled trial published in 1996¹⁰. In it, 68 outpatients with mild insomnia took a high-dose valerian and lemon balm preparation¹⁰. After two weeks, their sleep quality and daytime well-being had improved more than on placebo, with no hangover or rebound seen¹⁰. The summary doesn’t name the product or who paid for the study.

A Swiss summary from 2013 describes a 2006 study of children under 12 who took a tablet with 160 milligrams of valerian extract and 80 milligrams of lemon balm extract¹¹. After at least four weeks, about three in four of the 918 children evaluated who started with moderate or severe sleep trouble or restlessness had mild symptoms or none¹¹.

But it was an open study run after the product was on the market, with no placebo group, so no one can say how much came from the tablets and how much from time¹¹. And EU authorities don’t recommend valerian for children under 12⁴.

Lemon balm tea has its own quality questions, covered in our herbal tea guide.

The evidence at a glance

Use	Form and dose studied	Rating
Sleep, valerian alone	Many trials of extracts and dried root; NCCIH calls results inconsistent (see our sleep-aid scorecard)2	Not enough evidence
Anxiety disorders	One 4-week trial with 36 patients6	Not enough evidence
Next-morning alertness	600 mg extract, one trial with 102 volunteers7	Promising but early that it doesn’t impair
Valerian and hops for insomnia	Two tablets of 187 mg valerian and about 42 mg hops, 4 weeks, no better than placebo; a low-dose blend also failed112	Not enough evidence
Valerian and lemon balm, adults	One placebo-controlled trial with 68 outpatients, known from a summary10	Promising but early
Valerian and lemon balm, children	One study with no comparison group11	Not enough evidence
Menopause hot flashes	Three small studies2	Promising but early
Depression, PMS, menstrual cramps	Too little research, says NCCIH2	Not enough evidence

Safety: rare liver cases, withdrawal and sedative stacking

For most adults, valerian looks safe for short-term use. NCCIH says 300 to 600 milligrams a day for up to six weeks appeared safe, though long-term safety is unknown². Side effects can include mental dullness, excitability and uneasiness², plus nausea and stomach cramps⁴.

Liver. LiverTox, the NIH liver-injury database, describes only a small number of cases³. Most involved blends with other herbs such as skullcap or black cohosh³. Injury appeared 3 to 12 weeks after starting, was usually mild to moderate, and cleared within 2 to 4 months of stopping³. LiverTox rates valerian a probable rare cause of liver injury and found no convincing case of liver failure from valerian alone³.

One case shows why blends deserve caution. A 57-year-old woman developed jaundice about three weeks after starting a product believed to contain valerian, hops, asafetida and gentian³. Her jaundice lasted about four months, and she hadn’t fully recovered 10 months later³.

Withdrawal. Stopping valerian suddenly after long use may bring anxiety, irritability, heart disturbances and insomnia, and rarely hallucinations, NCCIH says².

Doctors at Duke University described one such case in a 1998 letter to JAMA¹³. A 58-year-old man had taken large doses of valerian for years for sleep and anxiety; a clinical newsletter adds that he took it five times a day and had heart disease⁸¹³. He was admitted for a lung biopsy, and his supplements were stopped¹³.

About a day later his heart was racing and he was confused, so he was moved to intensive care¹³. Doctors suspected valerian withdrawal and gave him a Valium-like drug by vein. He recovered and went home about a week after surgery¹³.

Sedatives and alcohol. Don’t mix valerian with alcohol or sedatives, NCCIH advises². ODS warns of possible added effects with benzodiazepines, barbiturates, other nervous-system depressants, St. John’s wort, kava and melatonin¹. List valerian on any medicine form, especially before surgery or a procedure.

Drug enzymes. In lab tests, 14 commercial valerian products slowed CYP3A4, a liver enzyme that clears many medicines⁸. Whether that matters in people is unclear, and the EU review found no interactions reported in the medical literature⁴. Ask a pharmacist if you take prescription drugs.

Pregnancy and children. The EU says not to use valerian during pregnancy or breastfeeding or in children under 12⁴. ODS adds that children under 3 shouldn’t take it¹.

Trying valerian safely: a checklist

1. Talk to a clinician first if your sleep trouble or anxiety has lasted weeks, or if you take any prescription medicine.
2. Choose a single-herb product that names the plant part and the amount or extract per dose¹.
3. Compare the dose with the EU figures: 400 to 600 milligrams of extract, or 0.3 to 3 grams of root for tea⁵.
4. Be wary of blends with tiny amounts of several herbs, or with other herbs tied to liver injury¹³.
5. Test it on a night before a day with no driving⁴.
6. Give it 2 to 4 weeks, and see a clinician if you’re no better after 2 weeks or getting worse⁵.
7. Skip alcohol, sleeping pills and other sedating herbs while you take it¹².
8. Don’t stop suddenly after months of daily use. Ask a clinician how to ease off².
9. Stop and call your doctor if your skin or eyes turn yellow³.

If a child swallows valerian or another supplement, call Poison Control at 1-800-222-1222¹⁵. If you have a bad reaction, stop the product, keep the bottle and tell your clinician.

Questions readers ask

The bottom line

Valerian’s written record reaches back to ancient Greece, and Europe has given one form official status. That standing comes with limits: specific extracts, set doses, a few weeks of use, and a warning about driving.

The evidence for anxiety is thin, and most popular blends have little testing behind them. Used briefly, alone and without alcohol or sedatives, valerian is low risk for most adults. Skip it in pregnancy and for young children, don’t stop suddenly after long use, and see a clinician if sleep or worry problems persist.

Related reading

• The sleep aid with the clearest warning is the drugstore antihistamine
• Doctors’ first choice for insomnia is retraining your sleep with CBT-I
• How to judge a cup of herbal tea, which is gentle but not automatically harmless
• Anxiety responds to therapy, medicine and exercise, and some calming herbs carry real risks
• Ashwagandha lowers a stress hormone, and regulators are now splitting root from leaf

Sources

1. NIH Office of Dietary Supplements. “Valerian: Fact Sheet for Health Professionals.” National Institutes of Health, updated March 15, 2013. ods.od.nih.gov
2. National Center for Complementary and Integrative Health. “Valerian.” NIH, last updated May 2025. nccih.nih.gov
3. National Institute of Diabetes and Digestive and Kidney Diseases. “Valerian.” LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, last updated April 5, 2020. ncbi.nlm.nih.gov
4. European Medicines Agency. “Valerianae Radix: Herbal Medicinal Product” (overview page with summary for the public, last updated March 11, 2026). Accessed October 2026. ema.europa.eu
5. European Medicines Agency, Committee on Herbal Medicinal Products. “European Union Herbal Monograph on Valeriana officinalis L., radix.” EMA/HMPC/150848/2015 Corr.1, adopted February 2, 2016. ema.europa.eu
6. Miyasaka LS, Atallah ÁN, Soares B. “Valerian for Anxiety Disorders.” Cochrane Database of Systematic Reviews, 2006, Issue 4, CD004515. cochrane.org
7. Kuhlmann J, Berger W, Podzuweit H, Schmidt U. “The Influence of Valerian Treatment on ‘Reaction Time, Alertness and Concentration’ in Volunteers.” Pharmacopsychiatry, 1999;32(6):235–241 (record via Epistemonikos). epistemonikos.org
8. Kiefer D. “Valerian for Insomnia: The ‘Natural’ Valium.” Alternative Medicine Alert (Relias Media), 2007;10(10):109–113. reliasmedia.com
9. “Efficacy of Single Dose Antihistamine vs. Single Dose Valerian-Hops in Subjective Sleep Measures Among War Refugees: A Comparison Trial.” SciELO Brazil (journal of the Faculdade de Medicina da Universidade de São Paulo), March–April 2017. doi.org
10. Altorfer R. “Baldrian und Melisse: Hilfe beim Ein- und Durchschlafen” (on Dressing H, et al., Psychopharmakotherapie, 1996). Ars Medici, 2014;(3):161.
11. Bachmann C. “Phytotherapie gegen Ruhelosigkeit und Einschlafschwierigkeiten bei Kindern” (summary of Müller SF, Klement S, Phytomedicine, 2006;13:383–387). Phytotherapie, 2013;(3):565–566.
12. Culpepper L, Wingertzahn MA. “Over-the-Counter Agents for the Treatment of Occasional Disturbed Sleep or Transient Insomnia: A Systematic Review of Efficacy and Safety” (includes Morin CM, et al., Sleep, 2005;28(11):1465–1471; review supported by Pfizer). Primary Care Companion for CNS Disorders, 2015;17(6). pmc.ncbi.nlm.nih.gov
13. Duke Health. “Stopping Herbal Products Abruptly May Cause Withdrawal Symptoms” (on Garges HP, Varia I, Doraiswamy PM, “Cardiac Complications and Delirium Associated With Valerian Root Withdrawal,” JAMA, 1998;280(18):1566–1567). Duke University, November 10, 1998. corporate.dukehealth.org
14. Haslam O. “Proposed Dutch Supplement Rule Changes Could Force Product Reformulation.” NutraIngredients, October 6, 2026. nutraingredients.com
15. America’s Poison Centers. “Poison Help.” Accessed October 2026. poisonhelp.org