Introduction: The use of herbal and dietary supplements has increased occurrences of drug-induced liver failure. Acute liver failure (ALF) can rapidly progress to multiorgan failure with about 50% of patients requiring a liver transplant. About 10% of all ALF cases have been due to drug injury while only about 2% have been due to Wilson disease (WD). This article provides a detailed case review of ALF due to the use of alkaline water that was originally thought to be due to WD. Case Description/Methods: A 35-year-old male with no known past medical history is brought into the emergency department (ED) with altered mental status for the past 2 to 3 weeks. The patient was found to be in acute renal failure and ALF. Computed tomography (CT) of the head was unremarkable and a CT of the abdomen showed hepatomegaly and hepatic steatosis without evidence of cirrhosis. Abdominal ultrasound was negative for portal vein thrombus, and laboratory findings were significant for reduced ceruloplasmin. Due to the absence of other causes for his ALF, the patient's presentation was thought to be due to WD. An ophthalmologist conducted a slit-lamp exam, which was negative for Kayser-Fleischer rings. A liver biopsy showed focal liver cholestasis, bile ductular reaction, and mixed portal inflammation suggestive of drug-induced liver injury. Examination of the liver core biopsies displayed acute and chronic periportal inflammatory infiltrate with eosinophils. The patient’s acute encephalopathy completely resolved after six days, and the patient subsequently reported drinking an alkaline water daily 10-days before the onset of symptoms. After ten days, the patient was transferred to a transplant center, however, with improving liver function and resolution of symptoms, the patient was discharged home without the need for further treatment. (Figure) (Table). Discussion: Due to increased consumption of herbal and dietary supplements in the United States, the rates of drug-induced liver failure have increased. Many cases of drug-induced liver failure due to these sources are underreported and when they are discovered have been linked to increased rates of liver transplant. This case not only highlights drug-induced acute liver failure and its complicated presentation, but also brings into consideration alkaline water as a potential source for ALF. Cases such as this demonstrate that a thorough history and further understanding of herbal and dietary supplements cannot be overlooked when attempting to elucidate a source in instances of ALF.Figure 1.: Computed tomography of the head and abdomen. (a) Axial view of head. No abnormalities in the basal ganglia. (b) Coronal view of abdomen. Table 1. - Laboratory test results of the patient a day before admission, on the day of admission, five days after admission, ten days after admission, and two days after transfer to an outside facility Variable (normal range) Two days before admission Day of admission Five days after admission Ten days after admission Two days after transfer White Blood Cell k/mm3 (3.10-10.20) 11.13 26.27 14.75 12.20 13.17 Hemoglobin g/dL (13.1-16.8) 14.9 16.3 11.0 9.2 8.9 Platelet k/mm3 (119-332) 314 354 182 163 274 Lactic Acid mmol/L (0.50-1.90) > 11.70 1.08 1.39 BUN mg/dL (5-26) 9 18 102 30 38 Creatinine mg/dL (0.55-1.30) 0.81 2.11 11.11 1.97 2.0 Bilirubin, Total mg/dL (0.0-1.2) 0.5 2.1 5.0 1.7 1.3 Bilirubin, Direct mg/dL (< = 0.5) 1.6 2.9 1.1 AST U/L (8-34) 40 11,867 193 90 65 ALT U/L (10-49) < 7 1,001 171 394 289 Alk-Phos U/L (46-116) 89 152 135 165 126 INR (0.80-1.2) 5.37 1.19 0.95 1.0 Prothrombin time (9.3-12.4 seconds) 53 12.6 10.2 11.8 Ceruloplasmin mg/dL (16.0-31.0) 8.7 13.5 24.6 Copper ug/dL (72-166) 52 82 76 Urine Copper Level ug/L 2787 Urine Copper mcg/24hrs (9-71) 40 Alk-Phos (IU/L) to total bilirubin (mg/dL) ratio 72.38 AST, aspartate transaminase; ALT, alanine transaminase; Alk-Phos, alkaline phosphatase; INR, International Normalization Ratio; aPTT, activated partial thromboplastin