Chemical Component Summary

FormulaC18 H24 O2
Molecular Weight272.382
Isomeric SMILESC[C@]12CC[C@@H]3c4ccc(cc4CC[C@H]3[C@@H]1CC[C@@H]2O)O

Chemical Details

Formal Charge0
Atom Count44
Chiral Atom Count5
Bond Count47
Aromatic Bond Count6

Drug Info: DrugBank

DrugBank IDDB00783 
  • approved
  • investigational
  • vet_approved
DescriptionEstradiol is a naturally occurring hormone circulating endogenously in females. It is commercially available in several hormone therapy products for managing conditions associated with reduced estrogen, such as vulvovaginal atrophy and hot flashes. Some available forms of estradiol include oral tablets, injections, vaginal rings, transdermal patches, sprays, gels, and creams.[L11485,L11488,L11491, L11494,L11497,L11500,L11503] When used for oral or IM administration, estradiol is commonly synthesized as a pro-drug ester (such as [DB13952], [DB13953], [DB13954], [DB13955], and [DB13956]). Because it has a low oral bioavailability on its own, estradiol is commonly formulated with an ester side-chain. [DB00977] (EE) is a synthetic form of estradiol commonly used as the estrogenic component of most combination oral contraceptive pills (OCPs). Ethinyl estradiol is different from estradiol due to its higher biovailability and increased resistance to metabolism, rendering it more suitable for oral administration.
  • 17β-estradiol
  • Estradiolum
  • 17β-oestradiol
  • Estradiol hemihydrate
  • cis-Estradiol
Brand Names
  • Estracomb
  • Estradiol and Norethindrone Acetate
  • Estraderm-50
  • Climara Pro
  • Estraderm-25
IndicationEstradiol is indicated in various preparations for the treatment of moderate to severe vasomotor symptoms and vulvar and vaginal atrophy due to menopause, for the treatment of hypoestrogenism due to hypogonadism, castration, or primary ovarian failure, and for the prevention of postmenopausal osteoporosis. It is also used for the treatment of breast cancer (only for palliation therapy) in certain men or women with metastatic disease, and for the treatment of androgen-dependent prostate cancer (only for palliation therapy).[L11485,L11494,L11497] It is also used in combination with other hormones as a component of oral contraceptive pills for preventing pregnancy (most commonly as [DB00977], a synthetic form of estradiol). **A note on duration of treatment** Recommendations for treatment of menopausal symptoms changed drastically following the release of results and early termination of the Women's Health Initiative (WHI) studies in 2002 as concerns were raised regarding estrogen use.[A31626] Specifically, the combined estrogen–progestin group was discontinued after about 5 years of follow up due to a statistically significant increase in invasive breast cancer and in cardiovascular events.[A31627] Following extensive critique of the WHI results, Hormone Replacement Therapy (HRT) is now recommended to be used only for a short period (for 3-5 years postmenopause) in low doses, and in women without a history of breast cancer or increased risk of cardiovascular or thromboembolic disease.[A31628] Estrogen for postmenopausal symptoms should always be given with a progestin component due to estrogen's stimulatory effects on the endometrium; in women with an intact uterus, unopposed estrogen has been shown to promote the growth of the endometrium which can lead to endometrial hyperplasia and possibly cancer over the long-term.
  • Adrenal Cortex Hormones
  • Androgens and Estrogens
  • Anti-Gonadotropin-Releasing Hormones
  • Antiandrogens and Estrogens
  • BCRP/ABCG2 Inhibitors
  • G03FA16
  • G03FA06
  • G03FA09
  • G03FA14
  • G03CA53
CAS number50-28-2

Drug Targets

NameTarget SequencePharmacological ActionActions
Nuclear receptor subfamily 1 group I member 2MEVRPKESWNHADFVHCEDTESVPGKPSVNADEEVGGPQICRVCGDKATG...unknownbinder
Neuronal acetylcholine receptor subunit alpha-4MELGGPGAPRLLPPLLLLLGTGLLRASSHVETRAHAEERLLKKLFSGYNK...unknownbinder
G-protein coupled estrogen receptor 1MDVTSQARGVGLEMYPGTAQPAAPNTTSPELNLSHPLLGTALANGTGELS...unknownbinder
View More
Drug Info/Drug Targets: DrugBank 3.0: a comprehensive resource for 'omics' research on drugs. Knox C, Law V, Jewison T, Liu P, Ly S, Frolkis A, Pon A, Banco K, Mak C, Neveu V, Djoumbou Y, Eisner R, Guo AC, Wishart DS. Nucleic Acids Res. 2011 Jan; 39 (Database issue):D1035-41. | PMID:21059682

Related Resource References

Resource NameReference