From the Manufacturer's Label:
Urovex® Butterbur Extract supports healthy bladder function. This patented, standardized extract contains the biologically active components petasin and isopetasin and is specially processed to remove undesirable pyrrolizidine alkaloids. Urovex® Butterbur Extract may also be used for other traditional applications.
Manufactured by Source Naturals.Contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color.