Know2eat

Valerian

Valeriana officinalis

Herbs & Botanicals

What valerian may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedSleep qualityLimited evidence· 3 sources

Then, in order

About Valerian

A root and rhizome preparation used for insomnia and restlessness, containing valerenic acid, valepotriates and a distinctive sulphurous aroma. Aqueous and ethanolic extracts differ in composition.

Valerian is among the most-trialled sleep botanicals and the results remain frustrating: many small trials, mostly subjective sleep endpoints, high placebo response, and inconsistent findings when objective measures are used. Reviews repeatedly note that trials with better methods tend to find smaller effects, and that preparations vary so much that pooling them is questionable.

Sold as
Root extract capsule, Tablet, Tincture, Tea, Combination sleep formulas with hops or lemon balm
Standardised to
Sometimes standardised to 0.8% valerenic acid — a product without this marker may not resemble what was studied.
Also known as
Valerian root, Garden heliotrope, All-heal

Regulation: Registered in the EU as a traditional herbal medicinal product for sleep and mild nervous tension, a category that requires evidence of long-standing use rather than proof of efficacy.

What the research used

The amounts, forms and durations published trials of Valerian actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Insomnia and sleep quality

    300–900 mg

    Limited

    Root extract, taken before bed · Where stated, 0.8% valerenic acid · Single night to 6 weeks

    Aqueous and ethanolic extracts at the same milligram weight are different preparations, and several trials found effects only after two weeks of nightly use rather than on the first night.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

  • Evening

    Limited

    Every trial dosed it 30 minutes to two hours before bed, so the evening window is universal protocol rather than a tested comparison — no study has compared evening dosing against any other time.

    Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Sleep quality

Sleep
Limited evidence

Some trials report improved subjective sleep quality, while objective measures such as sleep latency on polysomnography often show no difference. Reviewers describe the evidence as inconsistent and note that better-conducted trials find less.

What may be going on: Valerenic acid interacts with GABA-A receptors in laboratory work, which is a plausible but unconfirmed route to sedation.

Limited evidence. Early human work, or mostly lab and animal research.

View the 3 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Stress and anxiety

Mental Wellbeing
Not enough evidence

Evidence is limited for valerian and anxiety. The trials that exist are small, short and often use combination products with lemon balm or hops.

Not enough evidence. Not enough human research to say anything useful yet.

View the 3 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Interaction

    Additive sedation

    Interacts withBenzodiazepines, zolpidem, opioids, alcohol, sedating antihistamines

    Valerian can add to the sedative effect of alcohol, benzodiazepines, Z-drugs, opioids, antihistamines and anaesthetics. The combination affects driving and machinery use, and anaesthetists advise stopping before surgery.

  • Worth knowing

    Withdrawal after long-term use

    A case report describes a benzodiazepine-like withdrawal syndrome with delirium and cardiac symptoms after abrupt cessation of high-dose long-term valerian.

  • Worth knowing

    Liver injury reports

    Rare cases of hepatitis have been attributed to valerian, more often in combination products where another ingredient may be responsible. Persistent nausea or jaundice warrants stopping.

  • Avoid

    Pregnancy, breastfeeding and children

    Safety data are inadequate in pregnancy and breastfeeding, and valepotriates are cytotoxic in laboratory work. Use in young children is not supported.

  • Worth knowing

    Paradoxical stimulation and morning grogginess

    A minority of users report restlessness or vivid dreams instead of sedation, and next-morning drowsiness is a common complaint at higher doses.

Evidence ratings on this page: 1 limited evidence, 1 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Valerian, or a dose to follow.