The herb of the narrow-flowered or small-flowered willowherb.
No pharmacopoeial quality description.
HMPC monograph: Traditional-use: complaints of the urinary tract in benign prostatic hyperplasia (BPH) after exclusion of serious diseases
ESCOP: not processed.
Commission E: no monograph
Traditional medicine: Prostate diseases, especially benign prostatic hyperplasia, gastrointestinal diseases