Androsterone (ADT) is a steroid hormone with weak androgenic activity. It is made in the liver from the metabolism of testosterone.It was first isolated in 1931, by Adolf Friedrich Johann Butenandt and Kurt Tscherning. They distilled over 17000 litres of male urine, from which they got 50 milligrams of crystalline androsterone, which was sufficient to find that the chemical formula was very similar to estrone.Androsterone has been shown to naturally occur in pine pollen and is well known in many animal species.