Valerian
Valeriana officinalis
A sedative herb used for centuries to promote sleep and reduce anxiety, acting on GABA-A receptors. Multiple meta-analyses support its modest but meaningful effect on sleep quality.
What is Valerian?
Valerian (Valeriana officinalis) is a perennial flowering plant native to Europe and Asia. The root and rhizome have been used as a sedative and sleep aid since ancient Greek and Roman times — Hippocrates described its properties, and Galen prescribed it for insomnia. Its distinctive pungent odor is due to isovaleric acid and other volatile compounds. Valerian remains one of the most widely used herbal sleep aids globally, available over-the-counter in most countries.
Known Health Benefits
How It Works
Valerian's sedative effects arise from multiple synergistic mechanisms. Valerenic acid is a positive allosteric modulator of GABA-A receptors, specifically at the β3 subunit, enhancing GABAergic inhibitory neurotransmission without the full agonist activity of benzodiazepines. The root contains measurable amounts of GABA itself, though whether this crosses the blood-brain barrier is debated. Isovaleric acid also inhibits the GABA-degrading enzyme GABA transaminase, increasing synaptic GABA availability. Additionally, valerian constituents inhibit the enzyme-induced breakdown of GABA in the brain, and the iridoids (valepotriates) contribute mild spasmolytic (muscle-relaxant) effects. Lignans such as olivil have partial agonist activity at adenosine A1 receptors, another sleep-promoting pathway. These combined mechanisms produce a gentle sedative effect without the sharp pharmacological curve of synthetic sedatives.
What Research Says
Fernández-San-Martín et al. (2010) conducted a meta-analysis of 18 RCTs and found valerian significantly improved subjective sleep quality, though not polysomnographic measures. Bent et al. (2006) in a systematic review concluded valerian is safe and modestly effective for sleep, noting significant heterogeneity among preparations. Leathwood et al. (1982) published one of the first controlled studies showing reduced sleep latency with 450 mg valerian extract. A 2020 systematic review by Shinjyo et al. confirmed anxiolytic effects across multiple trials. Importantly, a study by Ziegler et al. (2002) found valerian (600 mg/day for 6 weeks) comparable to oxazepam for non-organic insomnia, with fewer side effects. Valerian consistently shows a favorable safety profile with effects that may build over 2–4 weeks of regular use.
Active Compounds
Valerenic acid, isovaleric acid, iridoids, GABA
Forms & Bioavailability
Valerenic acid is well absorbed orally with peak plasma levels at 1–2 hours. The complex mixture of volatile oils, iridoids, and lignans creates a phytochemical matrix where bioavailability of individual compounds is enhanced by the whole extract. Tea preparations provide faster onset but less standardized dosing than capsules. Effects often build over 2–4 weeks of consistent use.
Dosage Guidance
| Use Case | Dosage |
|---|---|
| Insomnia | 300–600 mg extract before bed |
| Anxiety | 200–400 mg 3× daily |
| Tea | 2–3 g dried root per cup |
| Tincture | 1–3 mL (1:5) before bed |
Always consult a healthcare provider for personalized dosing.
Potential Side Effects
Drowsiness, headache, GI upset in some individuals; do not drive after use
Who Should Avoid It
- Concurrent use of prescription sedatives or benzodiazepines
- Driving or operating heavy machinery after use
- Scheduled surgery (discontinue 2 weeks prior due to anesthesia interactions)
- Children under 3 years
- Liver disease (rare hepatotoxicity reports)
Pregnancy & Lactation
Insufficient safety data during pregnancy; most references advise against use. Animal studies have not shown teratogenicity, but human data is lacking. Not recommended during lactation due to sedative potential in the nursing infant.
Known Drug Interactions
May enhance effects of sedatives, benzodiazepines, and alcohol
Evidence Classification
Supported by cohort studies, case-control studies, or multiple observational studies with consistent findings.
Frequently Asked Questions
How long does valerian take to work for sleep?
Single-dose effects may be noticed within 30–60 minutes, but valerian is most effective when taken consistently over 2–4 weeks. Many clinical trials show improving sleep quality scores over this period. Unlike pharmaceutical sleep aids, valerian's effects are gradual and cumulative.
Can I combine valerian with melatonin?
Yes, this is a common combination. Valerian promotes GABA-mediated relaxation while melatonin signals the circadian sleep-wake cycle. They work through different mechanisms and are often found together in sleep formulas. Start with lower doses of each to assess tolerance.
Why does valerian smell so bad?
The distinctive odor comes from isovaleric acid and other volatile compounds in the root. This is actually one marker of quality — a strong-smelling valerian root is more likely to contain therapeutic levels of active compounds. Capsule forms mask the smell effectively.
Is valerian habit-forming?
No. Unlike benzodiazepines, valerian does not appear to cause tolerance, dependence, or withdrawal symptoms at recommended doses. The Ziegler et al. study comparing valerian to oxazepam specifically noted the absence of rebound insomnia or withdrawal effects upon discontinuation.
Can valerian help with anxiety during the day?
Yes. While most studies focus on sleep, several trials show anxiolytic effects at lower doses (200–400 mg) taken during the day. It may cause some drowsiness, so starting with a low daytime dose is advisable. It pairs well with L-theanine for daytime calm without sedation.
Does valerian interact with alcohol?
Yes. Both valerian and alcohol enhance GABAergic activity, and combining them can cause excessive drowsiness, impaired motor function, and CNS depression. Avoid alcohol on evenings when using valerian for sleep.
References
- Meta-analysis: valeriana extract and sleep quality. Fernández-San-Martín MI, Masa-Font R, Palacios-Soler L, et al.. Sleep Med (2010)View study
- Valerian for sleep: a systematic review and meta-analysis. Bent S, Padula A, Moore D, Patterson M, Mehling W. Am J Med (2006)View study
- Comparison of efficacy of valerian and oxazepam on non-organic insomnia: a randomized, double-blind clinical comparative study. Ziegler G, Ploch M, Miettinen-Baumann A, Collet W. Eur J Med Res (2002)View study
- Aqueous extract of valerian root improves sleep quality in man. Leathwood PD, Chauffard F, Heck E, Munoz-Box R. Pharmacol Biochem Behav (1982)View study
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This entry is for educational purposes only. It is not medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement regimen, especially if you take medications or have health conditions.