Nettle Leaf Extract

Nettle leaf extract is produced from the dried leaf and leafy tops of Urtica dioica L. (Urticaceae), the species the European Pharmacopoeia monograph on nettle leaf (Urticae folium) admits alongside Urtica urens L. and mixtures of the two. Incoming leaf is identified macroscopically, microscopically and by TLC against a pharmacopoeial reference before extraction, so the lot you buy is single-species Urtica dioica unless a mixed-species grade is specifically ordered. Leaf is extracted with water or ethanol-water, filtered, concentrated under vacuum and spray dried. Drying and extraction fully deactivate the stinging trichomes, so the finished powder handles like any other leaf extract. The leaf and the root are chemically different articles and Thovek quotes them separately. Nettle leaf is characterised by hydroxycinnamic acids - caffeoylmalic acid reported to around 1.6% and chlorogenic acid to around 0.5% in the dried herb - together with flavonol glycosides of quercetin and kaempferol, carotenoids, chlorophyll and a mineral fraction that includes calcium, magnesium, iron, zinc and silica. The Ph. Eur. limit for the herbal substance is minimum 0.3% total caffeoylmalic and chlorogenic acids expressed as chlorogenic acid. Nettle root, by contrast, is the part characterised by lignans, scopoletin and phytosterols such as beta-sitosterol, which has been measured at roughly 50 mg per 100 g of dried root. Buyers whose specification calls for a sterol or lignan marker should order the root article, not this one; a leaf extract will not meet a beta-sitosterol assay. The commercial standardisation on leaf is silica, declared as SiO2 and set at minimum 1.0%, which reflects nettle being among the richer plant sources of silica at up to about 1% of leaf dry weight. Native ratio grades of 4:1 and 10:1 are also stocked for formulators who prefer a stated drug-to-extract ratio over a marker assay. Material is vegan and vegetarian, carries none of the declarable allergens, and ships with certificate of analysis, heavy-metal and microbiological data, pesticide residue screening on request, MSDS, allergen and GMO statements, and a botanical identity certificate naming the plant part and country of origin.