BACKGROUND/AIMS: A double-blinded trial evaluating silymarin, an herbal supplement for liver disease, to prevent complications of chronic hepatitis C virus infection has not been done.

SUBJECTS: One hundred and seventy-seven consenting residents of an Egyptian village with chronic hepatitis C virus were randomly assigned to receive either silymarin or multivitamin supplements.

METHODS: Participants had baseline and follow-up clinical, ultrasound, blood tests and quality-of-life assessments. Community nurses visited weekly to ascertain compliance, distribute supplements and record adverse effects.

RESULTS: At 12 months almost all of 141 remaining subjects reported feeling better, although symptoms and quality-of-life scores did not differ between the silymarin and multivitamin groups. Both the silymarin and vitamins were tolerated equally well; and >95% of supplements were taken by >95% of subjects. One in each group had no detectable hepatitis C virus antibodies while two in the silymarin group and three receiving multivitamins had undetectable hepatitis C virus RNA. Serum alanine aminotransferase elevations did not differ between groups. Serum hepatic fibrosis marker, hyaluronic acid and YKL-40, and abdominal ultrasound results were similar in both groups and may have progressed slightly at 12 months.

CONCLUSIONS: The recommended dose of silymarin can be safely taken for 1 year and improves symptoms and general well-being, but has no effect upon hepatitis C virus viremia, serum ALT, or serum and ultrasound markers for hepatic fibrosis. More prolonged evaluation and a higher dose may be required to ascertain whether milk thistle supplements prevent complications of chronic hepatitis C virus.