Combined birth control pill The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. The pill contains two important hormones: progesti ...

s that contain natural estradiol or an estradiol ester (e.g., estradiol valerate) include: * Estradiol valerate and cyproterone acetate (brand name Femilar) – introduced in

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

(only) in 1993 * Estradiol valerate and dienogest (brand names Qlaira, Natazia) – introduced in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

in 2009 and the in 2010 * Estradiol and nomegestrol acetate (brand name Zoely) – introduced in Europe in 2011 Estradiol, mainly as esters including estradiol valerate, estradiol cypionate, and

estradiol enanthate Estradiol enantate (EEn or E2-EN), also spelled estradiol enanthate and sold under the brand names Perlutal and Topasel among others, is an estrogen medication which is used in hormonal birth control for women. It is formulated in combination wi ...

, is also the exclusive estrogen used in

combined injectable contraceptive Combined injectable contraceptives (CICs) are a form of hormonal birth control for women. They consist of monthly injections of combined formulations containing an estrogen and a progestin to prevent pregnancy. CICs are different from progestoge ...

s. As of 2021, more than 95% of prescriptions are for combined hormonal birth control forms containing the

synthetic Synthetic things are composed of multiple parts, often with the implication that they are artificial. In particular, 'synthetic' may refer to: Science * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic o ...

estrogen ethinylestradiol (EE). Hence, estradiol-based birth control pills are still not widely used.

Side effects

Birth control pills containing estradiol have less impact on liver protein synthesis than ethinylestradiol-containing birth control pills, and it is thought that for this reason, they may pose less of a risk of

venous thromboembolism Venous thrombosis is blockage of a vein caused by a thrombus (blood clot). A common form of venous thrombosis is deep vein thrombosis (DVT), when a blood clot forms in the deep veins. If a thrombus breaks off (embolizes) and flows to the lungs to ...

(VTE). In accordance, although birth control pills containing estradiol valerate/dienogest are associated with a significantly increased risk of VTE, they are associated with a significantly lower risk of venous thromboembolism than birth control pills containing ethinylestradiol and a progestin. The risk of VTE with

estradiol/nomegestrol acetate Nomegestrol acetate/estradiol (NOMAC-E2), sold under the brand names Naemis and Zoely among others, is a fixed-dose combination medication of nomegestrol acetate, a progestogen, and estradiol, an estrogen, which is used in menopausal hormone ther ...

birth control pills is under study. Incidence of irregular vaginal bleeding may be higher with estradiol-containing birth control pills in relation to the fact that estradiol is a weaker estrogen than ethinylestradiol in the

endometrium The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The functional laye ...

Pharmacology

The

pharmacodynamics Pharmacodynamics (PD) is the study of the biochemical and physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or combinations of organisms (fo ...

and

pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered ...

of estradiol in the context of use in birth control pills have been studied and reviewed.

Research

Experimental estradiol-containing birth control pills that were studied but never marketed include: * Estradiol/norethisterone (Netagen, Netagen 403) * Estradiol/estriol/norethisterone (Netagen 423) * Estradiol/estriol/norethisterone acetate * Estradiol/desogestrel * Estradiol cyclooctyl acetate/desogestrel * Estradiol/ethinylestradiol/dienogest A large

randomized controlled trial A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical te ...

of a birth control pill containing

ethinylestradiol/norethisterone acetate Ethinylestradiol/norethisterone acetate (EE/NETA), or ethinylestradiol/norethindrone acetate, is a combination of ethinylestradiol (EE) and norethisterone acetate (NETA) which is used as birth control and menopausal hormone therapy. EE is an e ...

versus a birth control pill containing estradiol/estriol/norethisterone acetate has been conducted.

References

{{Progesterone receptor modulators Estradiol Estrogens Hormonal contraception Progestogens

Side effects

Pharmacology

Research

See also

References