The Root That Calls the Rats — and Lulls Kings to Sleep

La Leggenda

It is told — and the telling is older than the first German printing presses — that the Pied Piper of Hamelin had no magic in his flute. He had something far more real in his pockets: **valerian roots**. Wrapped within his motley clothing, that dark and fetid powder drew rats as honey draws flies. The sound was the spectacle. The herb was the secret.

It is also told that the witches of the North knew this power in reverse: not to summon, but to *repel*. Dioscorides, the great Greek physician of the first century, advised hanging the root in the home as an amulet against malign influences — and for centuries, in the villages of northern Europe, a bundle of valerian above the door was a seal, not a remedy. It is told that Hertha, the Nordic goddess of the earth, would scatter it across her riding crop to give strength and speed to the stag upon which she rode through the winter sky.

Then there is the more intimate story: that medieval healers called valerian *"herba benedicta"* — the blessed herb — and used it in love potions not to kindle passion, but to **quiet the insomnia of a wounded heart**. Not a philtre to make one fall in love: a philtre to bring sleep to those who can no longer find it.

Il Vero

Valerian (*Valeriana officinalis* L.) is a perennial plant native to Europe and the temperate regions of Asia. Its name derives almost certainly from the Latin *valere* — "to be well," "to be strong" — and its documented history spans more than two thousand years: **Hippocrates described its therapeutic properties in the fifth century B.C.**, Dioscorides recommended it for sleep disturbances in the first century A.D., and Galen prescribed it for insomnia in the second.

But the heart of the mystery is chemical. Within the dried root a constellation of molecules ripens — valepotriates, isovaleric acid, lignans — and above all **valerenic acid**, the compound that modern research has identified as the protagonist of its sedative effect. The mechanism is today relatively well understood: valerian is thought to act by inhibiting the degradation of GABA, the brain's principal inhibitory neurotransmitter. In plain terms: **it slows the voice of the nervous system**, like gradually turning down the volume in a room grown too loud. Recent studies indicate that its extracts bind to GABA-A receptors in a manner similar to benzodiazepines — the modern anxiolytic drugs — but with a different, less selective affinity, and with a far milder side-effect profile.

The meta-analysis published in *BMC Complementary Medicine and Therapies* (2020, PMC7585905) systematically analysed the available literature, confirming the use of valerian as a sedative and sleep aid already documented in the eighteenth century, and a multiplicity of constituents isolated over the past 120 years — though the precise mechanism remains a subject of ongoing research.

Now, the legend of the Pied Piper. **It is not entirely absurd.** Rats are attracted to isovaleric acid — one of the volatile compounds of the root — because they perceive it as a familiar olfactory signal associated with territory and food. Cats too react to valerian with behaviours similar to those triggered by catnip (*Nepeta cataria*), owing to molecules structurally akin to the iridoids present in both plants. The keeper of Hamelin who perfumed his pockets with dried root was no sorcerer: he was, perhaps, **a man who could read chemistry before chemistry had a name**.

The smell, after all, is the true portal of this plant. Fresh, the flower is sweet and almost honeyed — the pale pink flowering tops carry the scent of wild vanilla. But the dried root develops isovaleric acid through enzymatic oxidation, and that fragrance becomes **earthy, ferrous, almost animal**: something between aged cheese and forest soil after rain. It is the smell of the threshold — of something that was once alive and now guards the border between waking and sleep.

As for its use in cooking and herbalism: valerian is classified as safe (*Generally Recognized As Safe*) by the American FDA for specific food uses, and continues to be one of the best-selling herbal supplements in Europe for sleep support, regulated as a herbal medicinal product by the EMA (European Medicines Agency) with an indication for "mild nervous tension and difficulty in falling asleep."