Great product, definitely should be part of any daily supplement program. As mentioned in the Quercetin & Pterostilbene review, when you mix these together, they are amplified and more powerful. It has been described to me as Vitamin C is what allows any other supplement to penetrate, so without it most supplants are almost useless. Vitamin C is also in itself an antioxidant, making it perfect for preventing diseases on its own. Dr. Mercola makes an excellent, convenient supplement to get the right amount of Vitamin C and has proven to be very effective. I highly recommend.