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Valerian
Valerian — what the European monograph actually supports, what it is not for, the form and how long it is meant to be used, side effects, and the 3 medicine interactions documented for it.
This is a reference page, not a diagnosis and not a prescription. Herbal products are real pharmacology: they have effects, side effects and interactions with medicines. Tell your doctor and your pharmacist everything you take, including teas and supplements, and never stop or change a prescribed medicine because of anything you read here.
What it is
Valeriana officinalis L. — root (Valerianae radix)
Local names across the region this site serves: palderjan (ET) · rohtovirmajuuri (FI) · валериана (RU).
Grouped here under Sleep, stress and calm. Regulatory position: EU herbal monograph — traditional use.
What the evidence supports
The registered indication: Relief of mild nervous tension and to aid sleep.
Valerian root is registered across the EU as a traditional herbal medicinal product, which means its licence rests on decades of use rather than on trials. Independent reviews of the trial evidence keep arriving at the same place: the studies are small, their results disagree, and the preparations differ so much in extract strength and solvent that pooling them honestly is not possible. Plenty of people report it helps them settle; what has not been shown is a consistent effect beyond placebo. It also does not behave like a sleeping tablet — there is no reliable knock-out dose, and traditional-use products are taken over a couple of weeks rather than on the bad night.
C — Traditional use only Plausible from thirty or more years of use, which is what a traditional-use registration means. No clinical evidence was required and none has settled it.
What it is not for
Insomnia that has lasted months, anxiety disorders, or sleep broken by a cause — pain, shift work, sleep apnoea, alcohol, depression. Those need the cause found, not a herb layered on top.
Form, strength and how long
Dried root as an infusion, a tincture, or dry-extract tablets, very often blended with hops, lemon balm or passionflower. Extract strengths differ enormously between products, so the amount printed on one pack tells you nothing useful about another.
Duration. Traditional-use products are for short-term use. If sleep has not improved after about two weeks, that is the moment to see a clinician rather than to take more.
No gram figure appears on this page on purpose. The plant part, the extraction solvent and the drug-to-extract ratio together define a preparation, and a number taken from one does not describe another. The reasoning is set out on the hub; the amount that applies to you is the one printed on the pack you are holding, and a pharmacist will read it with you.
Side effects
Usually well tolerated. Stomach complaints and headache are reported. Daytime drowsiness happens, particularly with a late dose or a strong extract, and it is the reason for the driving warning on the pack.
Who should avoid it
Not recommended in pregnancy or while breastfeeding, because it has not been studied there. Traditional-use registrations generally exclude children under 12. Do not drive or use machines if it makes you drowsy.
Interactions with medicines
| Medicine or substance | What is described |
|---|---|
| Alcohol | Valerian is sedating and so is alcohol; taken together the drowsiness adds up in a way neither predicts on its own. This is the interaction people actually meet, and it is the reason the monograph tells you not to combine them. |
| Sleeping tablets, benzodiazepines and sedating antihistamines | Sleeping tablets, benzodiazepines, sedating antihistamines and opioid painkillers all push in the same direction. Adding a sedating herb on top of a prescribed sedative is stacking effects blind. |
| Planned surgery and anaesthesia | List valerian with your medicines before a general anaesthetic. Sedative effects can add to anaesthetic drugs, and the anaesthetist would rather know. |
The reverse view — start from the medicine rather than the plant — is in the medicine, food and alcohol interactions reference, and summarised for every herb on this site.
Sources: European Medicines Agency — Committee on Herbal Medicinal Products (HMPC), European Union herbal monographs · NIH National Center for Complementary and Integrative Health — herb fact sheets · checked 2026-09-06
Frequently asked questions
What is valerian used for?
Relief of mild nervous tension and to aid sleep. Valerian root is registered across the EU as a traditional herbal medicinal product, which means its licence rests on decades of use rather than on trials. Independent reviews of the trial evidence keep arriving at the same place: the studies are small, their results disagree, and the preparations differ so much in extract strength and solvent that pooling them honestly is not possible. Plenty of people report it helps them settle; what has not been shown is a consistent effect beyond placebo. It also does not behave like a sleeping tablet — there is no reliable knock-out dose, and traditional-use products are taken over a couple of weeks rather than on the bad night.
Does valerian work?
Graded C here: Plausible from thirty or more years of use, which is what a traditional-use registration means. No clinical evidence was required and none has settled it. Insomnia that has lasted months, anxiety disorders, or sleep broken by a cause — pain, shift work, sleep apnoea, alcohol, depression. Those need the cause found, not a herb layered on top.
How much valerian should I take?
This reference does not print gram figures, because they do not transfer between preparations of different extract strength. What can be said honestly is the form and the duration: Dried root as an infusion, a tincture, or dry-extract tablets, very often blended with hops, lemon balm or passionflower. Extract strengths differ enormously between products, so the amount printed on one pack tells you nothing useful about another. Traditional-use products are for short-term use. If sleep has not improved after about two weeks, that is the moment to see a clinician rather than to take more.
What are the side effects of valerian?
Usually well tolerated. Stomach complaints and headache are reported. Daytime drowsiness happens, particularly with a late dose or a strong extract, and it is the reason for the driving warning on the pack.
Does valerian interact with medicines?
Yes — documented for Alcohol, Sedatives, Surgery. Each one is described on this page, with a link to the medicine-side reference where one exists.
Others in sleep, stress and calm
Chamomile
Mild digestive complaints including bloating and flatulence; as a mouth rinse for minor inflammation of the mouth and throat; on the skin for minor irritation; as a steam inhalation for a cold.
Lavender
Relief of mild symptoms of mental stress and exhaustion, and to aid sleep; the oil is also registered as a bath additive.
Lemon balm
Relief of mild symptoms of mental stress and to aid sleep; and, separately, mild digestive complaints including bloating and flatulence.
Passionflower
Relief of mild symptoms of mental stress and to aid sleep.
Keep the whole list in one place
TempoLife logs supplements alongside food, sleep and how you actually felt — so the answer to "what are you taking?" is a screen, not a guess.