Valerian: Uses, Benefits, Dosage & Safety

Last updated: June 2026 · Reviewed by the FactoWiki Editorial Team for clarity and source accuracy

What is Valerian?

Valerian (Valeriana officinalis) is a flowering plant whose root has been used since ancient Greece and Rome as a remedy for sleeplessness and nervousness. It is the most widely used herbal sleep aid today, sold as capsules, teas and tinctures, often standardized to valerenic acid. Despite centuries of use and great popularity, its effect on sleep has been surprisingly hard to pin down.

What Valerian is commonly used for

In supplements, Valerian is taken mainly for sleep and to ease anxiety and restlessness, appearing in sleep and calm formulas alongside brain & memory products. It is marketed as a gentle, non-habit-forming sleep aid; whether it reliably works is genuinely uncertain.

How Valerian works

Valerian is thought to act on GABA, the brain's main calming neurotransmitter — the same system targeted by prescription sedatives — which would explain a mild sedative effect. The exact active compounds and mechanism remain unclear, and the gap between this plausible mechanism and inconsistent trial results is part of why valerian is so debated.

What the evidence says

Here's an honest snapshot of what published research suggests about Valerian — including where the evidence is limited.

• A meta-analysis of 18 randomised trials found valerian appeared to improve subjective sleep quality, but its effectiveness was not demonstrated on objective or quantitative measures. (PubMed)
• A separate systematic review of 16 trials found a benefit for self-rated sleep but flagged significant publication bias and methodological problems. (MedlinePlus)

Typical dosage used in studies

Studies use a wide range, commonly 300–600 mg of extract taken 30 minutes to two hours before bed; effects may build over a couple of weeks rather than working on the first night. This is general information from research, not a recommendation.

Side effects and safety

Valerian is generally well tolerated and considered non-habit-forming; possible effects include morning grogginess, headache, dizziness or vivid dreams. Paradoxically, a few people feel stimulated rather than sedated.

Medication interactions and who should avoid Valerian

Sources & further reading

The evidence summary above is drawn from these sources. For general, authoritative background you can also consult:

• PubMed-indexed study (PMID 20347389)
• MedlinePlus
• NIH Office of Dietary Supplements
• NIH National Center for Complementary and Integrative Health

Frequently asked questions

Does valerian actually help you sleep?

Meta-analyses suggest it may improve how rested people feel, but it does not reliably improve objectively measured sleep, and the evidence shows publication bias. Results vary a lot between people.

Is valerian addictive?

It is generally considered non-habit-forming, unlike prescription sleep medications, though it should not be combined with them.

How long does valerian take to work?

Some people feel an effect the first night, but research suggests benefits may build over one to two weeks of regular use.

Is valerian safe?

Generally well tolerated, with occasional grogginess or headache. It can add to the effect of alcohol and sedatives, so don't combine them.

How much valerian is used?

Commonly 300–600 mg of extract before bed. This is general information, not a recommendation.