The history of ursodeoxycholic acid (UDCA) therapy has been provided by Makino and Tanaka.1 Identified in 1902 from polar bear bile by Hammarsten, UDCA was isolated and crystallised by Shoda in 1927. In 1936, its chemical structure was determined by Iwasaki at Okoyama Medical University. Several years later (1954) a chemist at Tokyo Institute of Technology, Kanazawa, described a method of synthesising UDCA from cholic acid and chenodeoxycholic acid. Three years later, Tokyo Tanabe Pharmaceutical Company launched “Urso” as a choleretic that could improve symptoms related to liver dysfunction and maldigestion. In 1961, Ishida, reporting his experience of Urso administration in chronic hepatitis, noted an improvement of liver function tests in patients receiving the bile acid. This observation was replicated several times during the following two decades in Japan. Actually, UDCA really drew the attention of the western scientific community when it was shown that it could promote dissolution of cholesterol gallstones as well as chenodeoxycholic acid. The proof of concept study of UDCA in primary biliary cirrhosis showing a marked improvement in cholestasis under UDCA therapy was a further impetus for many studies aimed to define the biological properties of this “very special” bile …