Small-leafed knotweed is a flagship plant of Chinese pharmacopoeia originating in China. Its vine has been used for centuries by TCM because of its soothing and relaxing properties.

Yuan zhi is recommended for people whose mind is agitated. It calms the Shen (Spirit), responsible for cognitive health, and soothes nervousness in order to alleviate difficulties in falling asleep and concentration. Thus, by deeply relaxing the body and calming restlessness, Yuan zhi stimulates memory and concentration and promotes sleep.