 Single- and Multiple-Dose Silymarin Pharmacokinetics: Subjects will arrive at the MUSC GCRC in the morning where they will remain for approximately 10-hours for each of 4 separate blood drawing phases of the study. After checking in, and under medical supervision, a modification of a modified Treatment Emergent Symptoms Scale TESS will be administered and a registered nurse will place an indwelling venous catheter in each subjects arm to facilitate serial blood sampling. At 8 AM after urinary void and collection of an aliquot for creatinine analysis, subjects will take one 175 mg capsule of MT standardized to 80 SM 140 mg of SM. The rationale for product choice is discussed below. Subjects will be in a fasted state for 4 hours following MT administration to reduce any effect of food on absorption. A total of 12 blood samples 10 ml each will be taken over the next 24-hour period. All samples will be drawn in heparinized tubes and stored on ice until centrifugation at 4C. As flavonoids are notorious for their instability in biological matrices, no sample will remain on ice for longer than 15 minutes prior to centrifugation. Time points of blood collection will be immediately prior to the dose of MT 0 time point, and at 0.5 hours, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12, and 24 hours. A second TESS will be administered to the subjects 2 hours post-dosing, at a time generally expected to represent silybin Cmax. Subjects will be asked to return for 4 brief visits for collection of single blood samples through a separate venipuncture at time points of 24, 36, and 48 hours. This extended sampling will provide adequate PK data to determine Cmax, AUC, terminal t12, and Clo of SM flavonoids. Standard meals will be served by the registered dietician at the GCRC and will not include any other sources of flavonoids. The composition and amount of food eaten throughout the day will be recorded. Plasma will be acidified with 10 ml of 1M acetic acidml plasma and frozen immediately at -70C. This single dose assessment of silymarin pharmacokinetics will be conducted at three dosage levels of MT supplement in an attempt to span the usual therapeutic range of MT and will be performed on three distinct occasions separated by no less than a 7-day wash-out period. The doses of MT used will be 175 mg, 350 mg and 525 mg administered orally with 200 mL of water as one, two, and three capsules, respectively. Again, these doses as well as product could be changed if a more standardized supplement is made available through NIHNCCAM or some other source. The highest dose of MT supplement proposed for oral administration, 525 mg 420 mg SM does not pose any undue risk to subjects since SM doses of 420 mg to 800 mg has been administered to many patients with hepatic dysfunction in clinical trials with few side effects reported NLM, 2000; Saller et al., 2001. 