Ethisterone

Ethisterone (INN, USAN, also known as pregneninolone, 17α-ethynyltestosterone, and 19-norandrostane), is a steroidal progestin. It is the 17α-ethynyl analog of testosterone, and was synthesized in 1938 by Hans Herloff Inhoffen, Willy Logemann, Walter Hohlweg, and Arthur Serini at Schering AG in Berlin and marketed in Germany in 1939 as Proluton C and by Schering in the U.S. in 1945 as Pranone. It was the first orally-active progestin.