Ethisterone is a progestogen

Progestagen

Progestogens are a group of hormones including progesterone.The progestogens are one of the five major classes of steroid hormones, in addition to the estrogens, androgens, mineralocorticoids, and glucocorticoids. All progestogens are characterized by their basic 21-carbon skeleton, called a...

 hormone.

The first orally active progestin

Progestin

A progestin is a synthetic progestogen that has progestinic effects similar to progesterone. The two most common uses of progestins are for hormonal contraception , and to prevent endometrial hyperplasia from unopposed estrogen in hormone replacement therapy...

, ethisterone (pregneninolone, 17α-ethynyltestosterone or 19–norandrostane), the 17α-ethynyl

Ethynyl radical

The ethynyl radical, with chemical formula C2H, is an abundant interstellar polyatomic molecule that does not occur naturally on Earth. It was first observed by electron spin resonance isolated in a solid argon matrix at liquid helium temperatures in 1963 by Cochran and coworkers at the Johns...

 analog of testosterone

Testosterone

Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...

, was synthesized

Chemical synthesis

In chemistry, chemical synthesis is purposeful execution of chemical reactions to get a product, or several products. This happens by physical and chemical manipulations usually involving one or more reactions...

 in 1938 by Hans Herloff Inhoffen, Willy Logemann, Walter Hohlweg, and Arthur Serini at Schering AG

Schering

Schering AG was a research-centered German pharmaceutical company. It was founded in 1851 by Ernst Christian Friedrich Schering and merged with Bayer's pharma sector in December 2006. The company's headquarters was in Berlin-Wedding, Germany...

 in Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

 and marketed in Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 in 1939 as Proluton C and by Schering

Schering-Plough

Schering-Plough Corporation was a United States-based pharmaceutical company. It was founded in 1851 by Ernst Christian Friedrich Schering as Schering AG in Germany. In 1971, the Schering Corporation merged with Plough to form Schering-Plough. On November 4, 2009 Merck & Co...

 in the U.S.

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 in 1945 as Pranone.

Ethisterone was also marketed in the U.S. from the 1950s into the 1960s under a variety of trade names by other pharmaceutical companies

Pharmaceutical company

The pharmaceutical industry develops, produces, and markets drugs licensed for use as medications. Pharmaceutical companies are allowed to deal in generic and/or brand medications and medical devices...

 that had been members of the pre-World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 European hormone cartel

Cartel

A cartel is a formal agreement among competing firms. It is a formal organization of producers and manufacturers that agree to fix prices, marketing, and production. Cartels usually occur in an oligopolistic industry, where there is a small number of sellers and usually involve homogeneous products...

 (Ciba

Novartis

Novartis International AG is a multinational pharmaceutical company based in Basel, Switzerland, ranking number three in sales among the world-wide industry...

, Organon

Organon International

Organon is a human pharmaceutical company headquartered in Oss, Netherlands. In November 2007 the company became a part of Schering-Plough Corporation, acquired Organon, active pharmaceutical ingredient producer Diosynth , and its veterinary pharmaceutical sister company Intervet from Akzo Nobel. ...

, Roussel

Roussel Uclaf

Roussel Uclaf S.A. was the second largest French pharmaceutical company before it was acquired by Hoechst AG of Frankfurt, Germany in 1997, with pharmaceutical operations combined into the Hoechst Marion Roussel division...

).