Rehmannia, a name in traditional Chinese medicine, refers to the fresh or dried tuberous roots of Rehmannia glutinosa Libosch., a plant in the Scrophulariaceae family. It is primarily produced in Henan. It is harvested in the fall; the crown, fibrous roots, and soil are removed for fresh use, or the tuberous roots are slowly dried until about 80% dry. The former is commonly known as “fresh Rehmannia,” and the latter as “raw Rehmannia.”Fresh Rehmannia has the effects of clearing heat, generating body fluids, cooling the blood, and stopping bleeding. It is primarily used to treat heat-related yin deficiency, a crimson tongue with restlessness and thirst, rashes caused by warm toxins, hemoptysis and epistaxis, and swelling and pain in the throat;Raw Rehmannia has the effects of clearing heat, cooling the blood, nourishing yin, and promoting fluid production. It is primarily used to treat heat invading the营血 (ying-blood), rashes caused by warm toxins, hemoptysis and epistaxis, yin depletion due to febrile diseases, a crimson tongue with intense thirst, constipation due to fluid depletion, fever due to yin deficiency, bone-consumptive fever, and internal heat-induced diabetes.