The difference between raw dihuang and cooked dihuang is mainly in the method of concoction, flavor, and efficacy. Raw Dihuang is the fresh root of the plant Dihuang, sweet, bitter and cold in nature, with the effects of nourishing yin, clearing heat, cooling blood, stopping bleeding and dispersing knots, it is used for treating heat illnesses that injure the yin, thirst, macular rash, vomiting of blood, and swelling and pain in the throat. It is not suitable for people with deficiency and coldness of the spleen and stomach (spleen and stomach weak and cold), and with scanty food and loose stools (thin and unformed feces). It should not be used in conjunction with veratrum. Radix Rehmanniae Praeparata (熟地黄) is a concoction of Radix Rehmanniae Praeparata (地黄), mostly stewed or steamed in yellow wine. It is sweet and warm in nature, and has the effect of nourishing yin and nourishing blood (nourishing the blood in the body), and filling in the marrow (replenishing the vital essence and fluid to promote the development of bone marrow). It is often used to treat deficiency of heart and blood, and deficiency of kidney essence. It is contraindicated in cases of stagnation of qi and phlegm, distention and pain in the epigastrium, and loose stools with little food. Dihuang should be used under the guidance of a Chinese medicine practitioner for identification of symptoms and avoid unauthorized use of the drug to avoid adverse effects. If there is any discomfort, please consult a doctor promptly.