What is the difference between Kudzu root (Pueraria lobata) and Powdered Kudzu root (Pueraria thomsonii)?
May 13, 2025
Source: Cainiu Health
Dr. Yu Yongchao
Introduction
Under normal circumstances, the main differences between Gegen (Radix Puerariae) and Fenge (Puerariae Lobatae Radix) include their appearance, composition, effects, origin, and uses. Gegen is generally presented as thick, longitudinally cut rectangular slices or small square pieces, with a surface usually yellow-white or light brownish, having longitudinal wrinkles and a rough texture. Fenge typically appears cylindrical, spindle-shaped, or semicylindrical, with a yellow-brown or brownish surface that exhibits longitudinal wrinkles and horizontal elongated lenticels.
Generally, the main differences between Gegen (Radix Puerariae) and Fenge (Pueraria starch) include appearance, composition, effects, origin, and usage. A detailed analysis is as follows:
1. Appearance
Gegen typically appears as longitudinally cut thick slices or small square blocks. Its outer skin is mostly yellow-white or light brown with longitudinal wrinkles and a rough texture. Fenge is usually cylindrical, spindle-shaped, or semi-cylindrical. Its outer skin is yellow-brown or brownish with longitudinal wrinkles and horizontal lenticels.
2. Composition
Gegen mainly contains isoflavonoids such as puerarin, daidzin, and daidzein, as well as small amounts of coumarins and triterpenoids. The composition of Fenge is similar to that of Gegen, but Fenge has a higher starch content. Meanwhile, the levels of isoflavonoids like puerarin in Fenge are relatively lower.
3. Effects
Gegen has effects of relieving muscle tension and reducing fever, promoting body fluid production to relieve thirst, uplifting yang energy, and stopping diarrhea. It is commonly used to treat conditions such as fever and headache caused by exogenous pathogens, stiff neck and back, thirst, diabetes, heat-induced dysentery, and diarrhea. Fenge has effects similar to Gegen, but its ability to promote body fluid production and relieve thirst and reduce fever is relatively weaker.
4. Origin
Gegen is the dried root of Pueraria lobata (Willd.) Ohwi, a plant from the Leguminosae family. Pueraria lobata mostly grows in grassy areas on hillsides, along roadsides, and in shady, moist places. Fenge is the dried root of Pueraria thomsonii Benth., also a Leguminosae plant. Fenge is mostly cultivated artificially and prefers warm, humid environments with ample sunlight.
5. Uses
Gegen is widely used in medicinal applications, such as in the production of Chinese patent medicines and herbal decoction pieces, and also in health preservation, for example, Gegen tea. Additionally, Gegen is used in cosmetics due to its antioxidant properties and can be incorporated into skincare products. Besides limited medicinal use, Fenge is primarily used as food. Fenge can be directly consumed after steaming or boiling, with a sweet, fragrant, and glutinous texture. It can also be processed into葛粉 (Pueraria starch) for making various pastries, soups, and other foods, and can serve as an industrial raw material for starch and alcohol production.
Whether used for medicinal diets or daily consumption, both Gegen and Fenge have their unique values. When consuming or using medicinally, it is recommended to follow the guidance of professionals to ensure safety and effectiveness.
