Estradiol (medication)
, estradiol is available in the United States in the following forms:Oral estradiol valerate (Progynova) and other esters of estradiol that are used by injection like estradiol benzoate, estradiol enantate, and estradiol undecylate all are not marketed in the U.S. Polyestradiol phosphate (Estradurin) was marketed in the U.S. previously but is no longer available.
Estetrol (medication)
Estetrol was discovered in 1965 by Egon Diczfalusy and coworkers at the Karolinska Institute in Stockholm, Sweden, via isolation from the urine of pregnant women. Basic research on estetrol was conducted from 1965 to 1984. It was established that estetrol is exclusively synthesized in the fetal liver and hence that it is a fetal estrogen. By 1984, estetrol was regarded as a weak estrogen; interest fell, and research was virtually abandoned. Subsequently a project at Pantarhei Bioscience was started to investigate estetrol with state-of-the-art technologies in 2001, with the sole reasoning that estetrol must have some biological role or function of importance as it would not be produced in such high quantities in the fetus otherwise. By 2008, estetrol was of major interest for potential clinical use, and development was in-progress. As of 2018, it is in mid- to late-stage clinical development for a variety of indications.https://adisinsight.springer.com/drugs/800034634 It was initially developed by Pantarhei Bioscience and Estetra SA (subsequently renamed Estetra SPRL), and is now being developed by Mithra Pharmaceuticals.