Preparations made from stinging nettle are traditional remedies for urinary tract disorders, especially benign prostatic hypertrophy, or BPH, in men. This non-cancerous condition causes enlargement of the prostate gland that can interfere with urination. Today, stinging nettle is widely used in Europe to treat the problem. Clinical research supports the herb's usefulness for relief of BPH symptoms. For example, in a trial published in "Journal of Herbal Pharmacotherapy" that lasted six months and involved more than 600 subjects with BPH, 81 percent of subjects who consumed a nettle preparation experienced lessening of symptoms compared to a placebo group. In addition, Memorial Sloan-Kettering says that nettle may slow growth of prostate cancer in laboratory animals. However, clinical studies with human subjects are needed to confirm this possible benefit.