Products containing 4-methylumbelliferone as their active substance have been available in the USA and Europe since 1990, as dietary supplements (under trade names Heparvit®, Heparmed®, DetoxPro®). These products are promoted as supporting liver function and improving detoxification. In many parts of Europe, products containing 4-methylumbelliferone are also available as drugs, and used as spasmolytics and choleretics [ref 11] (improving liver detoxification systems through increased bile production).