Randomized, double-blind study of freeze-dried Urtica dioica in the treatment of allergic rhinitis.

Ninety-eight individuals took part in a double-blind randomized study comparing the effects of a freeze-dried preparation of Urtica dioica (stinging nettles) with placebo on allergic rhinitis. Sixty-nine individuals completed the study. Assessment was based on daily symptom diaries, and global response recorded at the follow-up visit after one week of therapy. Urtica dioica was rated higher than placebo in the global assessments. Comparing the diary data Urtica dioica was rated only slightly higher.