Prothoracicotropic hormone
Prothoracicotropic hormone (PTTH) was the first insect hormone to be discovered. It was originally described simply as "brain hormone" by early workers such as Stefan Kopeć (1922) and Vincent Wigglesworth (1934), who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached. After a certain point the ligation had no effect and both sections of the insect would molt or pupate. However, implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause would induce molting or pupation. Thus, the brain was originally thought to be the source of the hormone that induces molting in insects.
Progynon
Progynon was an orally active formulation of estrogen that was developed by Adolf Butenandt at Schering and introduced in Germany in 1928. It was reportedly the first sex hormone product and hence also the first estrogen product to be introduced for medical use. Progynon was originally an ovarian or placental extract, but Schering soon switched for economic reasons to using the urine of women who were in late pregnancy. This form of Progynon was essentially the same product as Emmenin, which was developed by James Collip at Ayerst and introduced in Canada in 1930 (and in the in 1934).