Valerian Root: Nature’s Sleep Herb, Put to the Test

Valerian root smells like old socks, and people have been taking it anyway for about two thousand years. Greek and Roman physicians wrote about it, and today it is one of the best-selling herbal sleep aids in the world. It also gets credited with calming anxiety, quieting restless legs, easing period cramps and cooling hot flashes. That is a lot of jobs for one root.

So we went through the reviews and the individual trials to see which of those claims hold up. Short version: valerian is gentle, generally well tolerated, and has real (if modest) evidence for how well people feel they sleep and for some menstrual and menopause symptoms. It is not a sleeping pill, and several of the popular claims have little or no research behind them yet.

How valerian is thought to work

The root of Valeriana officinalis contains valerenic acid, valepotriates and a mix of volatile oils. The leading theory is that these compounds nudge the GABA system, the brain’s main “brake pedal” for nerve activity. In lab studies, valerenic acid acts on GABA-A receptors, the same family of receptors that prescription sedatives target, but far more gently. The US National Institutes of Health describes this as a proposed mechanism: it is plausible, but it has not been confirmed in people.

That gentleness is the point. Valerian does not knock you out the way a sleeping pill can, which is why most studies that found a benefit used it nightly for two to four weeks rather than judging a single dose.

🌙 Sleep: better for how rest feels than for the numbers

This is valerian’s main job, and the evidence is genuinely mixed. A 2020 systematic review of 60 studies concluded that valerian could improve subjective sleep quality, meaning people reported sleeping better, with more reliable results from whole root preparations and from combinations with hops or passionflower. The NIH notes that some trials found people fell asleep a little faster, on the order of 7 to 16 minutes, although it is unclear how meaningful that is.

The less flattering side: a 2024 umbrella review that pooled eight earlier reviews (over 15,000 participants) found no convincing evidence that valerian treats clinical insomnia when sleep is measured objectively, and rated most of the underlying research as low quality. The American Academy of Sleep Medicine’s 2017 guideline also advises against valerian as a treatment for chronic insomnia.

Our read: for occasional trouble winding down, valerian is a reasonable, low-risk thing to try for a few weeks. For true chronic insomnia, the best-supported treatment is cognitive behavioral therapy for insomnia (CBT-I), and it is worth seeing a doctor to rule out sleep apnea or another cause.

😰 Stress and nervousness: the evidence is thin

Because of the GABA connection, valerian is often sold for stress, racing thoughts and a nervous stomach. The 2020 review found modest calming effects across eight small anxiety studies, but results were inconsistent. A Cochrane review looking specifically at anxiety disorders found too little good evidence to say whether valerian works at all.

It may take the edge off everyday tension for some people. It is not a replacement for treatment of generalized anxiety disorder or panic attacks, which respond well to therapy and, where needed, medication.

🦵 Restless legs: not enough evidence to recommend it

Restless legs syndrome (RLS) causes an uncomfortable urge to move the legs, usually at night, which wrecks sleep. In a small 2009 placebo-controlled trial, adults with RLS took 800 mg of valerian at bedtime for eight weeks. Both groups improved, and on the main measures valerian did not clearly beat placebo, although people who started out very sleepy during the day seemed to do better on it.

That is too little to recommend it for RLS. Low iron is a common and very fixable cause, so ask your doctor to check your ferritin before reaching for herbs.

🌸 Menstrual discomfort: a surprisingly good result

Valerian has a traditional reputation as an antispasmodic, meaning it relaxes smooth muscle like the uterus. A 2011 randomized, placebo-controlled trial in 100 students with painful periods gave 255 mg of valerian three times a day during the first three days of bleeding. Pain severity dropped significantly more than with placebo, and fainting, fatigue and nausea improved too.

It is one of the more encouraging findings on this list, although it comes from a small number of studies, mostly from one region. Severe period pain can also signal endometriosis or fibroids, so it deserves a proper check-up.

🔥 Menopause: hot flashes and sleep

Several small trials, many from Iran, have tested valerian in menopausal women. A 2013 placebo-controlled trial found that eight weeks of valerian capsules reduced both the severity and the frequency of hot flashes, and another trial found improved sleep quality in postmenopausal women taking it twice a day for four weeks. The 2020 review agreed that the menopause data look positive.

For women who cannot or prefer not to use hormone therapy, that makes valerian worth discussing with your doctor. Just keep expectations modest: the studies are small and short.

🤕 Everyday tension in the neck, shoulders and jaw

Herbalists have long used valerian for stress held in the neck, shoulders and jaw, mostly because of its relaxing, antispasmodic reputation. We could not find any good trials testing valerian for tension headaches or muscle spasms directly, so this one sits firmly in the “traditional use” column. If it helps you unwind in the evening, a looser jaw may be a side benefit, but it is not a proven headache treatment.

🛡️ Feeling wired and burnt out

Some people use valerian to take the edge off a nervous system that feels stuck in “fight or flight”, whether from chronic stress, burnout or past trauma. There are no clinical trials of valerian for PTSD or trauma-related hyperarousal. Those conditions respond well to trauma-focused therapy, so please see a professional rather than self-treating. Valerian can be a gentle part of a wind-down routine, not the treatment itself.

How to use it sensibly

• Follow the label. Studies used roughly 300 to 600 mg of extract, or 2 to 3 g of dried root, taken 30 minutes to 2 hours before bed. Liquid extracts are dosed in drops or millilitres, so check the serving size.
• Give it two to four weeks. Valerian tends to work gradually, so one night is not a fair test.
• Build the habit around it. Consistent wake time, a dark cool room and no screens in bed will do more than any herb, and valerian works best on top of them.
• Check what is in the bottle. The product we link to is an alcohol-based tincture. If you avoid alcohol for any reason, look for an alcohol-free glycerite or a capsule instead.
• Watch the morning after. Most people feel fine, but some feel groggy. Do not drive until you know how it affects you.

Who should skip it or ask first

• Anyone pregnant or breastfeeding. There is not enough safety data.
• Children under 3, and older children unless a doctor has advised it.
• People taking sedatives, sleep medication, benzodiazepines, opioids, sedating antihistamines or alcohol, because the effects can add up.
• Anyone having surgery. Stop about two weeks before, since it may add to the effect of anesthesia.
• People with liver disease. Rare cases of liver injury have been reported, mostly with multi-ingredient products.

In trials, side effects were uncommon and mild, mainly headache, dizziness, stomach upset and morning drowsiness, and happened at rates similar to placebo.

The honest bottom line

Valerian root is a gentle, low-risk herb with modest benefits. The best evidence says it can help some people feel they sleep better, and small trials support it for period cramps and menopause symptoms. The anxiety and restless legs evidence is weak, and the headache and trauma claims have not been tested. Try it for a few weeks alongside good sleep habits, and if sleep problems keep going, talk to a doctor about CBT-I and possible underlying causes.

Studies and sources

• Valente et al. (2024). Does valerian work for insomnia? An umbrella review of the evidence. European Neuropsychopharmacology.
• Shinjyo, Waddell and Green (2020). Valerian root in treating sleep problems and associated disorders: a systematic review and meta-analysis. Journal of Evidence-Based Integrative Medicine.
• Valerian fact sheet for health professionals. NIH Office of Dietary Supplements.
• Sateia et al. (2017). Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults. Journal of Clinical Sleep Medicine.
• Miyasaka et al. (2006). Valerian for anxiety disorders. Cochrane Database of Systematic Reviews.
• Cuellar and Ratcliffe (2009). Does valerian improve sleepiness and symptom severity in people with restless legs syndrome? PubMed.
• Mirabi et al. (2011). Effects of valerian on the severity and systemic manifestations of dysmenorrhea. PubMed.
• Mirabi and Mojab (2013). The effects of valerian root on hot flashes in menopausal women. PMC.

This article is for general education and is not medical advice. Talk to your doctor or pharmacist before starting a supplement, especially if you take medication or have a health condition. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.