Complementary and alternative medical (CAM) therapies are a diverse group of practices that includes the use of herbal and dietary supplements (HDS) (table 1) . The use of CAM therapies in the United States increased dramatically since 1990. As many as 65 percent of the population reported the use of CAM therapies, depending upon how they were defined, with out-of-pocket costs in 2007 exceeding $33.9 billion [2-6]. The most commonly used CAM therapies were herbal and dietary supplements, and 44 percent ($14.8 billion) of all out-of-pocket costs were for the purchase of nonvitamin, nonmineral natural products .
Between 1997 and 2002, overall CAM therapy use remained relatively stable . By contrast, the use of HDS increased by 50 percent (from 23 million adult users to over 38 million) . Between 2002 and 2007, use increased from 36 to 38 percent of the United States population [5,6]. The estimated cost of HDS alone in 2008 was $4.8 billion . In addition, about 95 percent of CAM users were self-medicating (compared with 85 percent in 1997) . The most common reason for their use is for health improvement and maintenance . Women and Alaska Natives/American Indians were more likely to use CAM therapies, with greater use in persons younger than 65 years of age and in those with a higher annual household income [1,2,9,10].
Use of herbal preparations can be traced back as far as ancient Egypt, China, India, and Sumeria, and formulations have been expanded upon over the centuries [11,12]. Many patients consider "natural" herbal remedies to be completely free of unwanted side effects [13-15]. This is concerning since many herbal products have biological activity that can lead to severe toxicity or that interact with each other or with prescription medications. Fewer than 40 percent of patients disclose to their clinician that they are using these products [1,2,16].
DATABASE OF DRUGS, HERBS, AND SUPPLEMENTS ASSOCIATED WITH HEPATOTOXICITY
Over 1000 medications and herbal products have been implicated in the development of drug-induced liver injury, and the list continues to grow [17,18]. A searchable database of drugs, herbal medications, and dietary supplements associated with hepatotoxicity has been developed by the National Institutes of Health .
In 1962, the Kefauver-Harris Drug Amendment required that all over-the-counter and prescription products show proof of safety and efficacy . Complementary and alternative medicines (CAMS) were assigned to the food supplement category and had a lower threshold of required evidence for safety . An attempt by the Food and Drug Administration (FDA) in the early 1990s to develop more strict regulations was met with significant opposition by supplement manufacturers, lobbyists, and consumers.