Open-label studies, anecdotal reports, and in vitro scientific research indicate that 4-methylumbelliferone (active ingredient of the dietary supplement Heparvit®) may prevent and reverse the symptoms and complications of chronic infection with hepatitis B virus (HBV)and hepatitis C virus (HCV). This effect has been observed among naïve patients as well as those who are non-responders to interferon, commonly used as first-line therapy for HBV and HCV. In order to scientifically address the efficacy of this 4-methylumbelliferone on chronic viral hepatitis, a randomized, placebo-controlled, blinded study is needed.