Herb Pharm, Burdock Blend, 1 fl oz (30 ml)Cleanse & Detoxify Herbal Supplement Burdock Blend Liquid Extract All of the herbs in this formula are individually extracted to ensure a broad spectrum of therapeutic plant compounds. To assure optimal potency, we harvest roots from first year plants, and seeds from fully matured second year plants. These are each extracted separately according to their individual biochemistry and are then blended together to produce our Burdock Blend.