Rehmannia has been used extensively in traditional Chinese medicine (TCM). Although thorough clinical trials are lacking, rehmannia has been used to treat rheumatoid arthritis, asthma, urticaria (hives), and chronic nephritis (kidney inflammation) in Chinese studies. Rehmannia may also be used to prevent the suppressive effects of corticosteroid (steroid) drugs. Rehmannia looks promising in treating aplastic anemia, mitigating side-effects of chemotherapeutic agents and HIV medications, curing obdurate eczema (dry skin), relieving pain from lung or bone cancer or disc protrusion, and helping ameliorate lupus nephritis (kidney inflammation) and type 2 diabetes with hyperlipidemia (high cholesterol). However, presently, there are no high-quality, large randomized, controlled trials supporting the efficacy of rehmannia for any of these indications. Rehmannia is in the Pharmacopoeia of the People's Republic of China . However, it is not on the United Kingdom's General Sale List, and is not covered by a Commission E monograph in Germany. The U.S. Food and Drug Administration (FDA) has not granted generalized recognized as safe (GRAS) status to rehmannia; it is available in the United States as a dietary supplement under the Dietary Supplement Health and Education Act of 1994.