Dietary Supplement. Certified Potency® ~ 100mg Extract per Capsule. Nature s Herbs® Kudzu Extract is a high quality form of kudzu extract. A source of the isoflavone Daidzin, 1% per capsule, Nature s Herbs Kudzu Extract is standardized with a concentration of naturally balanced active principles while retaining and enhancing whole-plant synergistic benefits, making it one of the world s finest and purest concentrated plant extracts. How it Works Kudzu is a hardy climbing vine that is a member of the pea family. Introduced into the United States from Asia in 1876, kudzu now grows abundantly in the southeast. It was one of the earliest plants used in traditional Chinese medicine, and Asian c.