Poudre d'ortie (Urtica dioica)
Applied to the scalp, the humble nettle is said to promote the growth of strong, shiny hair by stimulating blood circulation, while preventing dandruff and balancing sebum production.
Nettles are widespread all over the world as they thrive in almost every soil and tolerate many different climates.
Dreaded by toddlers and clumsy people, they are famously irritant and can provoke a quite intense burning sensation on the skin. This is caused by the tiny hairs covering the plant, a defence system it has developed against herbivores. Fortunately, they lose this unpleasant quality when dried and, paradoxically, tend to soothe the skin thanks to anti-inflammatory components.
Powdered materials like this one are great for use in self-preserving cosmetics as the drier a product formula is, the less bacteria are able to grow, reducing the need for synthetic preservatives.