Stinging Nettles Freeze-Dried 420mg 120 tabs, Planetary HerbalsStinging Nettles Freeze Dried Herbal Sinus Support Dried nettle leaf is traditionally used as a tonifier. When carefully freeze dried, additional properties are preserved which support the sinuses. In vitro research on these constituents shows partial inhibitory effects on the biosynthesis of arachidonic acid and leukotrienes. Traditional Use of Nettles Stinging nettle (Urtica diocia) has been a staple of herbal practitioners for centuries. At one