The root of Rehmannia or Sheng di huang is native to the North-East of China. It is in the list of the fifty most valued plants by the pharmacopoeia of China.

Sheng di huang invigorates the body to overcome temporary weakness and protect it from external attacks. In TCM, this herb enriches the blood in order to prevent signs of aging such as premature hair whitening, muscle sensitivity or declining eyesight.