Caprifoliaceae

Valeriana officinalis

Valerian · All-heal

Mixed Caution

Part used: rootrhizome
Native range: Europe and temperate Asia; naturalised in North America
Morphology: Perennial to a metre and a half with pinnate leaves and domed heads of small pale pink flowers. The dried root has a powerful and widely disliked smell, often compared to old socks.

What is in it

valepotriates valtrate, didrovaltrate

sesquiterpenes valerenic acid

volatile oil

Evidence

Trials for insomnia are inconsistent. Subjective sleep quality sometimes improves; objective measures on polysomnography generally do not. Meta-analyses split on whether the effect is real, and the preparations vary widely.

Safety

Generally well tolerated in the short term. Headache, dizziness and paradoxical excitability occur. Hepatotoxicity has been reported, usually in combination products where attribution is difficult. Withdrawal-like symptoms are described after abrupt cessation of long-term use.

Interactions: Additive sedation with alcohol, benzodiazepines, opioids and antihistamines; Caution before surgery and general anaesthesia

Regulatory: Permitted as a listed medicine ingredient in Australia and widely available over the counter.

How the traditions classify it

Galenic Classed as hot and dry, and used for a wide range of complaints — the old English name all-heal reflects how broadly it was applied.

Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.

Historical use

Recorded by Dioscorides and Galen. Used across Europe for sleeplessness, nervousness and cramp, and adopted in the eighteenth and nineteenth centuries as a treatment for what was then called hysteria and for shell shock in the First World War.

Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.

Worth knowing

Valerian is a useful check on the assumption that a strong smell and a long history mean a strong effect.

The interesting split in the trial literature is between what people report and what the instruments record. Subjective sleep quality improves; polysomnography largely does not. That gap is not evidence of nothing happening — feeling that you slept better is not a trivial outcome — but it is exactly the pattern an expectancy effect produces, and the trials are not designed to separate the two.

Its family placement moved with the molecular revision of the Dipsacales: valerians used to have their own family, Valerianaceae, and now sit inside the honeysuckles.

Nomenclature verified against GBIF backbone taxonomy.