He Shou Wu, also known as Polygonum Multiflorum Root, or Fo-Ti, is a favored rejuvenating tonic in both Ayurvedic and Chinese medicine. It is used to increase and maintain energy and vigor.
According to traditional Chinese medical theory, the yin (body fluids) and yang (fire of life) forces of the body must exist in harmony and balance, or negative effects may arise. In the event of a yin or yang deficiency, the body may utilize precious vital energy in an attempt to overcome the imbalance. This use of energy, in turn, may bring about a qi deficiency, which affects the body's ability to age gracefully.