A third study, in contrast to the preceding study, found that a single 10 mg intramuscular injection of estradiol valerate resulted in maximal estradiol levels of 506 to 544 pg/mL and maximal estrone levels of 205 to 219 pg/mL in postmenopausal women.With intramuscular injections of estradiol valerate, it has been reported that a dose of 5 mg has a duration of 7 to 8 days, 10 mg a duration of 10 to 14 days, 40 mg a duration of 2 to 3 weeks (14 to 21 days), and 100 mg a duration of 3 to 4 weeks (21 to 28 days).A study of pseudopregnancy with intramuscular injections of 40 mg/week estradiol valerate and 250 mg/week hydroxyprogesterone caproate in women with estrogen deficiency observed estradiol levels of about 3,100 pg/mL at 3 months of therapy and 2,500 pg/mL at 6 months of therapy. Subcutaneous injection
Estradiol esters like estradiol valerate and estradiol cypionate can be given by subcutaneous injection instead of intramuscular injection. Intravenous injection
The administration of estradiol valerate by intravenous injection has been studied. It has been found to be very rapidly cleaved into estradiol. The bioavailability and metabolism of estradiol valerate does not differ with intravenous versus intramuscular injection. Conversely, intravenous injection of estradiol valerate has a very short duration, whereas intramuscular injection has a long duration and elimination half-life. Chemistry
Estradiol valerate is a synthetic estrane steroid and the C17β valerate (pentanoate) fatty acid ester of estradiol. It is also known as estradiol 17β-valerate or as estra-1,3,5(10)-triene-3,17β-diol 17β-pentanoate.
Some or all oral estradiol valerate tablets are micronized, similarly to oral estradiol tablets.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 at a concentration of 5 mg/mL in combination with the progestin hydroxyprogesterone caproate and with the progestin norethisterone enantate as combined injectable contraceptives. Intramuscular estradiol valerate is also marketed at a concentration of 4 mg/mL in combination with the weak androgen and neurosteroid prasterone enanthate (DHEA enanthate) and with the androgen testosterone enantate for use in menopausal hormone therapy, but the latter formulation has been discontinued. The availability of estradiol valerate-containing products varies throughout the world. Contraindications
Contraindications of estrogens include coagulation problems, cardiovascular diseases, liver disease, and certain hormone-sensitive cancers such as breast cancer and endometrial cancer, among others. Side effects
The side effects of estradiol valerate are the same as those of estradiol. Examples of such side effects include breast tenderness and enlargement, nausea, bloating, edema, headache, and melasma. High-dose estrogen therapy with estradiol valerate injections may also cause an increased risk of thromboembolism, changes in blood lipid profile, increased insulin resistance, and increased levels of prolactin. Overdose
Estradiol valerate has been used at very high doses of 40 to 100 mg once per week in women and men, without overt signs of acute toxicity observed. Symptoms of estrogen overdosage may include nausea, vomiting, bloating, increased weight, water retention, breast tenderness, vaginal discharge, heavy legs, and leg cramps.