NMA: Nonprescription Medicines Academy

Milk Thistle Shows No Benefit for Treatment-Resistant Chronic HCV Infection

August 29th, 2012

In a double-blind, placebo-controlled trial conducted at four U.S. medical centers, the botanical product silymarin—an extract of milk thistle—did not significantly reduce serum alanine aminotransferase (ALT) levels more than placebo in participants with chronic hepatitis C virus (HCV) infection that had been treated unsuccessfully with interferon-based therapy.

The trial included 154 patients with serum ALT levels ≥65 U/L at baseline. Participants were randomly assigned to one of three groups:

  • Silymarin 420 mg three times per day.
  • Silymarin 700 mg three times per day.
  • Matching placebo administered three times per day.
  • Treatment continued for a total of 24 weeks. The primary outcome measure was serum ALT level within the normal range (≤45 U/L), or <65 U/L if that level represented a 50% decrease from baseline values.

Only two participants in each study group met the primary outcome measure after 24 weeks of treatment (P ≥0.99). The corresponding percentages were 4.0% (95% CI, 0.5%–13.7%) for silymarin 420 mg, 3.8% (95% CI, 0.5%–13.2%) for silymarin 700 mg, and 3.8% (95% CI, 0.5%–13.2%) for placebo. The mean decline in serum ALT activity at the end of treatment did not differ significantly across the three study groups (P = 0.75).

JAMA. 2012;308:274-82.