Liver Injury Induced by Herbal Complementary and Alternative Medicine Victor J. Navarro, MD a, *, Leonard B. Seeff, MD b INTRODUCTION Before the emergence of pharmacology as a science and the proliferation of the pharmaceutical industry that fueled the development of chemical and biologic medi- cations, indigenous peoples who suffered illnesses or injuries depended on unconven- tional means of treatment, some now referred to as alternative medicine. A local healer was often consulted and might conduct animal sacrifice, perform incantations, or apply specific forms of scarification, whereas other approaches considered included prayer, massage, acupuncture, body manipulations, and especially the use of herbal medications. The use of herbal medications was particularly prevalent in the Far East, Disclaimer: Dr Seeff, The views expressed here are those solely of the author and not those of the U.S. Food and Drug Administration. Disclosures: The authors have nothing to disclose. Funding: Supported by NIDDK, NIH (7U01DK083027-06; PI: V.J. Navarro). a Division of Hepatology, Einstein Healthcare Network, 5401 Old York Road, Klein Building, Suite 505, Philadelphia, PA 19141, USA; b The Hill Group, 6903 Rockledge Drive, Suite 540, Bethesda, MD 20817, USA * Corresponding author. E-mail address: navarrov@einstein.edu KEYWORDS  Regulatory  Herbal  Dietary supplements  Hepatotoxicity  Causality assessment KEY POINTS  Herbal and dietary supplements (HDSs) are being used with increasing frequency in American households. Several products and specific ingredients have been implicated in liver injury.  The regulatory environment for HDSs is different than that for conventional medications; premarket testing for safety and efficacy is not required.  The diagnosis of liver injury caused by an HDS is made as it is for drugs. However, the causality assessment process is confounded by the possibility of product adulteration and contamination, which may account for injury.  Many different single herbal ingredients have been implicated in liver injury. However, multicomponent products are more likely to be implicated in liver injury, each with many ingredients making it difficult, if not impossible, to impugn any of them with certainty. Clin Liver Dis 17 (2013) 715–735 http://dx.doi.org/10.1016/j.cld.2013.07.006 liver.theclinics.com 1089-3261/13/$ – see front matter Ó 2013 Elsevier Inc. All rights reserved.