# Valerian for sleep: what the trials show

Source: https://sleepfacts.uk/sleep-aids/valerian/
Author: Tess Marlow · Updated 2026-11-04

**Short answer:** The evidence is weak and mixed. One review of 16 studies found people were more likely to report better sleep, but the studies were small and biased towards positive results. A later review of 18 trials found no measurable difference in time to fall asleep. Valerian is generally safe short term, but don't mix it with alcohol or other sedatives.

**Evidence grade:** Weak evidence. Small or short studies, surveys, or results that are mixed.

## What is valerian?

Valerian is a flowering plant whose dried root has been used as a sleep remedy since Roman times. In the UK it's sold in tablets, capsules and teas, often combined with hops or passionflower. Many products carry a THR (traditional herbal registration) mark, which means they meet quality and safety standards, but their use is based on long tradition rather than trial evidence.

## Does it work?

The trials point in different directions.

- **A 2006 review** of 16 studies with 1,093 people found those taking valerian were about 1.8 times as likely to report improved sleep as those on placebo. But the authors found signs of publication bias, meaning positive trials were more likely to be published than negative ones, and many studies were small or poorly run.
- **A 2010 review** of 18 randomised trials found no meaningful difference in the time it took to fall asleep, measured objectively: less than a minute. Scores for sleep quality didn't differ either, though people on valerian were somewhat more likely to say their sleep had improved.
- **A US trial of 184 adults** compared a valerian-hops combination for 28 days, the antihistamine diphenhydramine (as in Nytol) for 14 days, and a placebo. Both active treatments had modest effects, and few differences from placebo were statistically significant.

Put together, valerian may help some people feel they sleep better, but there's no convincing evidence that it changes how quickly you fall asleep or how long you sleep. US sleep medicine guidelines advise against it for chronic insomnia.

## Is it safe?

For most healthy adults, short courses seem low risk. Reported side effects include headache, dizziness, stomach upset and feeling groggy the next morning. There have been rare reports of liver problems with valerian products, though often in combination with other herbs.

Don't take valerian if you are pregnant or breastfeeding, or give it to children, without medical advice, because it hasn't been tested in these groups. Avoid alcohol, and don't combine it with other sleep aids or sedatives. Ask a pharmacist first if you take other medicines or have liver disease.

## Should you try it?

If you want a herbal remedy for a short bad patch, a THR-marked valerian product is a reasonable thing to try for a few weeks, as long as you don't expect much. For [insomnia](/sleep-problems/insomnia/) lasting months, [CBT for insomnia](/sleep-problems/cbt-for-insomnia/) has far better evidence.

## Frequently asked questions

### How long does valerian take to work?

Trials that found any benefit usually gave it nightly for two to four weeks, so a single dose is unlikely to do much. If you notice nothing after a few weeks, it probably isn't going to help.

### Can I take valerian with sleeping pills or antidepressants?

Ask a pharmacist or GP first. Valerian may add to the drowsiness of sleeping pills, sedating antihistamines, alcohol and some antidepressants and painkillers.

### Is valerian addictive?

There is no good evidence that it causes dependence like sleeping pills can. Some people report feeling unsettled if they stop suddenly after long use, so taper it if you've taken it for months.

## References

1. [Bent S et al. Valerian for sleep: a systematic review and meta-analysis. American Journal of Medicine, 2006.](https://pubmed.ncbi.nlm.nih.gov/17145239/)
2. [Fernández-San-Martín MI et al. Effectiveness of Valerian on insomnia: a meta-analysis of randomized placebo-controlled trials. Sleep Medicine, 2010.](https://pubmed.ncbi.nlm.nih.gov/20347389/)
3. [Morin CM et al. Valerian-hops combination and diphenhydramine for treating insomnia: a randomized placebo-controlled clinical trial. Sleep, 2005.](https://pubmed.ncbi.nlm.nih.gov/16335333/)
4. [Sateia MJ et al. Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults. Journal of Clinical Sleep Medicine, 2017.](https://pubmed.ncbi.nlm.nih.gov/27998379/)