Estradiol sulfate
As the sodium salt, sodium estradiol sulfate, E2S is present as a minor constituent (0.9%) of conjugated equine estrogens (CEEs), or Premarin. It effectively functions as a prodrug to estradiol in this preparation, similarly to E1S. E2S is also formed as a metabolite of estradiol, as well as of estrone and E1S. Aside from its presence in CEEs, E2S is not available as a commercial pharmaceutical drug.
Estradiol valerate
Estradiol valerate, sold under the brand names Delestrogen, Progynon Depot, and Progynova 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 hormonal birth control for women. It is also used in the treatment of prostate cancer in men. The medication is taken by mouth or by injection into muscle once every 1 to 4 weeks.
Side effects of estradiol valerate include breast tenderness, breast enlargement, nausea, headache, and fluid retention. Estradiol valerate is a synthetic estrogen and hence is an agonist of the estrogen receptor (ER), 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.
Estradiol valerate was first described in 1940 and was introduced for medical use in 1954. Along with estradiol cypionate, it is one of the most widely used esters of estradiol. Estradiol valerate is used in the United States, Canada, Europe, and throughout much of the rest of the world. It is available as a generic medication.