Linden Botanicals is my go to for herbal extracts. The purity and quality of their phyllanthus niruri (chanca piedra) is unlike any brand I've used before. It's an integral part of my daily wellness routine and you can definitely tell the difference in bioavailability between Linden and other brands. I use it for general health maintenance and digestion, but it's also a miracle product for kidney and gall stone sufferers. If you're like me and you don't want to take a million different supplements but are really looking for a product that provides a wide spectrum of health benefits...look no further. Although I purchase mostly to support bodily systems and as a preventative, I can definitely feel the difference when I run out.