Valerian root (Valeriana officinalis) is a traditional sleep remedy that may help some people fall asleep faster and sleep more deeply, though clinical results are inconsistent. It seems to work best when taken nightly for two to four weeks at doses of 300–600 mg of extract, taken 30 minutes to two hours before bed. It is generally safe for short-term use but can cause morning grogginess and should not be mixed with sedatives or alcohol.
Key takeaways
- Valerian has been used for insomnia since the time of Hippocrates and Galen.
- It may work by increasing GABA activity – the brain’s main calming signal.
- Typical dose: 300–600 mg extract or 2–3 g dried root as tea, before bed.
- Benefits often appear after 2–4 weeks of regular use, not the first night.
- Avoid with alcohol, sleeping pills, benzodiazepines, in pregnancy and in children under 12 (UK guidance).
What is valerian?
Valerian is a tall perennial with sweetly scented pink-white flowers that grows wild in damp meadows across Europe and parts of Asia, and has naturalised in North America. The medicinal part is the root and rhizome, which – once dried – develops a powerful, cheesy, “old socks” smell caused by isovaleric acid. Cats find it almost as irresistible as catnip.
The Greek physician Galen prescribed valerian for insomnia in the 2nd century, and during both World Wars it was given in Britain to calm people suffering from the stress of air raids.
How does valerian work?
Valerian contains several groups of active compounds: valerenic acid, valepotriates and lignans. Laboratory research suggests:
- Valerenic acid binds to GABA-A receptors and may inhibit the breakdown of GABA.
- Some lignans act on adenosine receptors, which help build “sleep pressure” through the day.
- Compounds may interact with serotonin 5-HT5a receptors involved in the sleep–wake cycle.
Does valerian work? The evidence
| Review | Finding |
|---|---|
| Bent et al., 2006 (meta-analysis) | Valerian might improve sleep quality, but study methods were weak and publication bias likely |
| Fernández-San-MartÃn et al., 2010 | Subjective improvement in sleep quality; no clear objective effect |
| Shinjyo et al., 2020 (systematic review) | Valerian could be a safe, effective herb for sleep and anxiety, but extracts and doses varied widely |
| NCCIH | Evidence is inconclusive |
The pattern is that people feel they sleep better, while lab sleep measurements show smaller effects. Whole-root preparations seemed to perform better than isolated extracts in one review.
How to take valerian
Dosage
- Extract: 300–600 mg of standardised root extract, 30 minutes to 2 hours before bed.
- Tea: 2–3 g of dried root steeped in 250 ml hot water for 10–15 minutes.
- Tincture: 1–3 ml (1:5 tincture) before bed.
Tips for best results
- Take it every night for at least two weeks before judging the effect.
- Combine with lemon balm or hops – combinations have been studied for restlessness and sleep.
- Mask the taste with peppermint, chamomile, honey or cinnamon in teas. Capsules avoid the smell entirely.
- Use it alongside good sleep habits: a regular schedule, a cool dark room and no screens before bed.
For gentler options, see the 7 best herbal teas for sleep.
Side effects
- Headache, dizziness, stomach upset and morning drowsiness (“hangover effect”), particularly at high doses.
- Vivid dreams in some people.
- A paradoxical stimulating effect in a small number of users.
- Rare reports of liver problems, usually with multi-herb products.
- Do not drive or operate machinery if you feel drowsy.
Who should avoid valerian?
- People taking benzodiazepines, barbiturates, opioids, sleeping pills, antihistamines or drinking alcohol.
- Pregnant or breastfeeding women.
- Children under 12 – UK THR-registered valerian products are labelled for adults and adolescents only.
- Anyone scheduled for surgery in the next two weeks, as it may interact with anaesthesia.
- People with liver disease.
Growing valerian
Valerian is very easy to grow in moist, fertile soil in sun or part shade, reaching up to 1.5 m. Harvest roots in autumn of the second year, wash and dry them quickly. Be aware it self-seeds freely and is considered invasive in some US states.
Frequently asked questions
How long does valerian take to work for sleep?
Some people notice effects within an hour, but studies suggest the best results come after taking valerian nightly for two to four weeks.
Is it safe to take valerian root every night?
Short-term nightly use for up to four to six weeks appears safe for most adults. Long-term safety is less studied, so take breaks and consult a professional for persistent insomnia.
Why does valerian smell so bad?
Dried valerian root contains isovaleric acid, which produces a strong, cheesy or sweaty smell. Capsules or blending with mint can help.
Can I take valerian with melatonin?
Some products combine them, but combining sleep aids can increase drowsiness. Ask a pharmacist before combining, especially if you take other medicines.
Does valerian cause dependence?
Valerian has not been shown to cause dependence or withdrawal like benzodiazepines, though rare withdrawal-like symptoms have been reported after long-term high-dose use.
Sources and further reading
- NCCIH – Valerian
- Bent S et al. (2006) Valerian for sleep: a systematic review and meta-analysis. American Journal of Medicine.
- Shinjyo N et al. (2020) Valerian root in treating sleep problems and associated disorders – a systematic review and meta-analysis. Journal of Evidence-Based Integrative Medicine.
