Depofemin

Estradiol cypionate (INN, USAN) (brand names Depo-Estradiol, Depofemin, Estradep, and many others), or estradiol cipionate, is a synthetic ester, specifically the 3-cyclopentylpropanoyl ester, of the natural estrogen, estradiol.It was first introduced in 1952 by Upjohn in the United States,and has been in widespread use since. Estradiol cypionate behaves as a sustained-release prodrug to estradiol, and therefore is considered to be natural estrogen.

Estradiol cypionate is absorbed more slowly than estradiol itself, and for that reason, can be administered less often.Compared to other commonly used estradiol esters, via the intramuscular route, estradiol cypionate was found to have the longest duration of action with a duration of ~11 days, while estradiol benzoate and estradiol valerate were found to last for 4-5 days and 7-8 days, respectively.Estradiol cypionate, as a depot injection, has been found to have equivalent effectiveness and pharmacokinetics (e.g., duration) via subcutaneous and intramuscular routes.However, subcutaneous injection is generally regarded as easier and less painful relative to intramuscular injection, and for these reasons, may result in comparatively greater patient compliance.

Lunelle and Cyclofem are combination formulations of 4 mg estradiol cypionate and 25 mg medroxyprogesterone acetate for intramuscular use as long-lasting (once-monthly) contraceptives.With these formulations, estradiol levels peak 2 days post-administration at mean serum levels of 247 pg/mL.The terminal half-life of estradiol with these formulations is approximately 8 days, and plasma estradiol levels return to baseline (typically about 100 pg/mL) by 14 days post-administration.At 28 days post-administration, estradiol levels reach a low of 40 to 55 pg/mL.