What are the effects and benefits of Shu Di Huang and Sheng Di Huang?

Raw rehmannia and prepared rehmannia refer to raw Rehmannia glutinosa and prepared Rehmannia glutinosa, respectively. Raw Rehmannia glutinosa is the fresh or dried tuberous root of the plant Rehmannia glutinosa Libosch., belonging to the Scrophulariaceae family. It has the functions of clearing heat, cooling blood, nourishing yin, and promoting body fluid production. Clinically, it is primarily used to treat conditions such as heat entering the nutrient-blood level, hematemesis, heat-induced injury of yin in febrile diseases, dark red tongue with irritability and thirst, fluid deficiency leading to constipation, deficiency-heat due to yin deficiency, and internal heat causing diabetes. Prepared Rehmannia glutinosa is a processed form of raw Rehmannia glutinosa. It functions to tonify blood, nourish yin, enrich essence, and replenish bone marrow. Clinically, it is mainly used to treat blood deficiency manifesting as sallow complexion, palpitations, irregular menstruation, liver and kidney yin deficiency, soreness and weakness of the lower back and knees, night sweats, spermatorrhea, internal heat causing diabetes, dizziness, tinnitus, and premature graying of hair.