<unk>  <unk> , sold under the brand name Progynon-B among others, is an estrogen medication which is used in hormone therapy for menopausal symptoms and low estrogen levels in women, in hormone therapy for transgender women, and in the treatment of gynecological disorders. It is also used in the treatment of prostate cancer in men.<unk>  is used in veterinary medicine as well. When used clinically, the medication is given by injection into muscle usually two to three times per week. Side effects of<unk>  include breast tenderness, breast enlargement, nausea, headache, and fluid retention.<unk>  is a synthetic estrogen and hence is an agonist of the estrogen receptor, the biological target of estrogens like estradiol. It is an estrogen ester and a prodrug of estradiol in the body. Because of this, it is considered to be a natural and bioidentical form of estrogen.<unk>  was discovered in 1933 and was introduced for medical use that same year. It was the first estradiol ester to be discovered or marketed, and was one of the first estrogens to be used in medicine. Along with estradiol dipropionate,<unk>  was among the most widely used esters of estradiol for many years following its introduction. However, in the 1950s, longer-acting estradiol esters that necessitated less frequent injections, such as estradiol valerate and estradiol cypionate, were developed, and have since largely superseded<unk> . Nonetheless,<unk>  remains widely available throughout the world. It is not available for medical use in the United States, but is available in this country for use in veterinary medicine.
Estradiol benzoate
Estradiol undecylate
Estradiol dienantate
Estradiol furoate
Estradiol enantate
Estradiol valerate
Estradiol dipropionate
Estradiol cypionate