Estradiol valerate
In addition to single-drug formulations, oral estradiol valerate is available in combination with the progestin dienogest as a combined oral contraceptive and intramuscular estradiol valerate is marketed in combination with the progestins hydroxyprogesterone caproate and norethisterone enantate as combined injectable contraceptives. Intramuscular estradiol valerate has also been marketed in combination with testosterone enantate, but this formulation has been discontinued. The availability of estradiol valerate-containing products varies throughout the world.
Estradiol undecylate
Estradiol undecylate, also known as estradiol undecanoate and formerly sold under the brand names Delestrec and Progynon Depot 100 among others, is an estrogen medication which has been used in the treatment of prostate cancer in men. It has also been used as a part of hormone therapy for transgender women. Although estradiol undecylate has been used in the past, it was discontinued and hence is no longer available. The medication has been given by injection into muscle usually once a month.
Side effects of estradiol undecylate in men include breast tenderness, breast development, feminization, sexual dysfunction, infertility, fluid retention, and cardiovascular issues. Estradiol undecylate 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 very long-lasting prodrug of estradiol in the body. Because of this, it is considered to be a natural and bioidentical form of estrogen. An injection of estradiol undecylate has a duration of about 1 to 4 months.
Estradiol undecylate was discovered in 1954 and was introduced for medical use by 1956. It has been used in Europe as a parenteral estrogen to treat prostate cancer in men, although not as often as polyestradiol phosphate.