Estrogen (medication)

Source: Wikipedia, the free encyclopedia.
This article is about estrogens as medications. For their role as hormones, see Estrogen.

Estrogen (medication)
ERβ, mERs (e.g., GPER, others))
External links
MeSHD004967
Legal status
In Wikidata

An estrogen (E) is a type of

synthetic steroidal estrogens like ethinylestradiol, and synthetic nonsteroidal estrogens like diethylstilbestrol.[1] Estrogens are one of three types of sex hormone agonists, the others being androgens/anabolic steroids like testosterone and progestogens like progesterone
.

blood clots, cardiovascular disease, and, when combined with most progestogens, breast cancer.[1] In men, estrogens can cause breast development, feminization, infertility, low testosterone levels, and sexual dysfunction
among others.

Estrogens are

antigonadotropic effects and at sufficiently high dosages can strongly suppress sex hormone production.[1] Estrogens mediate their contraceptive effects in combination with progestins by inhibiting ovulation
.

Estrogens were first introduced for medical use in the early 1930s. They started to be used in birth control in combination with progestins in the 1950s.[2] A variety of different estrogens have been marketed for clinical use in humans or use in veterinary medicine, although only a handful of these are widely used.[3][4][5][6][7] These medications can be grouped into different types based on origin and chemical structure.[1] Estrogens are available widely throughout the world and are used in most forms of hormonal birth control and in all menopausal hormone therapy regimens.[3][4][6][5][1]

Medical uses

Birth control

Main article: Hormonal contraception

Estrogens have

estradiol ester
.

Hormone therapy

Menopause

Main article:
Menopausal hormone therapy
oral estradiol in a randomized controlled trial of 333 menopausal women[8][9]

Estrogen and other hormones are given to postmenopausal women in order to prevent osteoporosis as well as treat the symptoms of menopause such as hot flashes, vaginal dryness, urinary stress incontinence, chilly sensations, dizziness, fatigue, irritability, and sweating. Fractures of the spine, wrist, and hips decrease by 50 to 70% and spinal bone density increases by approximately 5% in those women treated with estrogen within 3 years of the onset of menopause and for 5 to 10 years thereafter.

Before the specific dangers of conjugated estrogens were well understood, standard therapy was 0.625 mg/day of conjugated estrogens (such as Premarin). There are, however, risks associated with conjugated estrogen therapy. Among the older postmenopausal women studied as part of the

blood clotting. The WHI studies used one type of estrogen supplement, a high oral dose of conjugated estrogens (Premarin alone and with medroxyprogesterone acetate as Prempro).[10]

In a study by the NIH, esterified estrogens were not proven to pose the same risks to health as conjugated estrogens.

Menopausal hormone therapy
has favorable effects on serum cholesterol levels, and when initiated immediately upon menopause may reduce the incidence of cardiovascular disease, although this hypothesis has yet to be tested in randomized trials. Estrogen appears to have a protector effect on atherosclerosis: it lowers LDL and triglycerides, it raises HDL levels and has endothelial vasodilatation properties plus an anti-inflammatory component.

Research is underway to determine if risks of estrogen supplement use are the same for all methods of delivery. In particular, estrogen applied

thromboembolic disease
.

Estrogen is also used in the therapy of vaginal atrophy, hypoestrogenism (as a result of hypogonadism, oophorectomy, or primary ovarian failure), amenorrhea, dysmenorrhea, and oligomenorrhea. Estrogens can also be used to suppress lactation after child birth.

liver protein synthesis and associated health risks.[12]

Estrogen dosages for menopausal hormone therapy
Route/form Estrogen Low Standard High
Oral Estradiol 0.5–1 mg/day 1–2 mg/day 2–4 mg/day
Estradiol valerate 0.5–1 mg/day 1–2 mg/day 2–4 mg/day
Estradiol acetate 0.45–0.9 mg/day 0.9–1.8 mg/day 1.8–3.6 mg/day
Conjugated estrogens 0.3–0.45 mg/day 0.625 mg/day 0.9–1.25 mg/day
Esterified estrogens 0.3–0.45 mg/day 0.625 mg/day 0.9–1.25 mg/day
Estropipate 0.75 mg/day 1.5 mg/day 3 mg/day
Estriol 1–2 mg/day 2–4 mg/day 4–8 mg/day
Ethinylestradiola 2.5–10 μg/day 5–20 μg/day –
Nasal spray Estradiol 150 μg/day 300 μg/day 600 μg/day
Transdermal patch Estradiol 25 μg/dayb 50 μg/dayb 100 μg/dayb
Transdermal gel
 Estradiol 0.5 mg/day 1–1.5 mg/day 2–3 mg/day
Vaginal
 Estradiol 25 μg/day – –
Estriol 30 μg/day 0.5 mg 2x/week 0.5 mg/day
SC injection
 Estradiol valerate – – 4 mg 1x/4 weeks
Estradiol cypionate 1 mg 1x/3–4 weeks 3 mg 1x/3–4 weeks 5 mg 1x/3–4 weeks
Estradiol benzoate 0.5 mg 1x/week 1 mg 1x/week 1.5 mg 1x/week
SC implant Estradiol 25 mg 1x/6 months 50 mg 1x/6 months 100 mg 1x/6 months
Footnotes: a = No longer used or recommended, due to health concerns. b = As a single patch applied once or twice per week (worn for 3–4 days or 7 days), depending on the formulation. Note: Dosages are not necessarily equivalent. Sources: See template.

Hypogonadism

Estrogens are used along with progestogens to treat hypogonadism and delayed puberty in women.

Transgender women

Main article: Feminizing hormone therapy

Estrogens are used along with

transgender women and other transfeminine individuals.[13][14][15]

Hormonal cancer

Prostate cancer

See also: Management of prostate cancer § Estrogen therapy

gonadotropin-releasing hormone analogues and nonsteroidal antiandrogens. It is still sometimes used in the treatment of prostate cancer however,[16] and newer estrogens with atypical profiles such as GTx-758
that have improved tolerability profiles are being studied for possible application in prostate cancer.

Estrogen dosages for prostate cancer
Route/form Estrogen Dosage
Oral Estradiol 1–2 mg 3x/day
Conjugated estrogens 1.25–2.5 mg 3x/day
Ethinylestradiol 0.15–3 mg/day
Ethinylestradiol sulfonate 1–2 mg 1x/week
Diethylstilbestrol 1–3 mg/day
Dienestrol 5 mg/day
Hexestrol 5 mg/day
Fosfestrol 100–480 mg 1–3x/day
Chlorotrianisene 12–48 mg/day
Quadrosilan 900 mg/day
Estramustine phosphate 140–1400 mg/day
Transdermal patch Estradiol 2–6x 100 μg/day
Scrotal: 1x 100 μg/day
SC injection
 Estradiol benzoate 1.66 mg 3x/week
Estradiol dipropionate 5 mg 1x/week
Estradiol valerate 10–40 mg 1x/1–2 weeks
Estradiol undecylate 100 mg 1x/4 weeks
Polyestradiol phosphate Alone: 160–320 mg 1x/4 weeks
With oral EE: 40–80 mg 1x/4 weeks
Estrone 2–4 mg 2–3x/week
IV injection
 Fosfestrol 300–1200 mg 1–7x/week
Estramustine phosphate 240–450 mg/day
Note: Dosages are not necessarily equivalent. Sources: See template.

Breast cancer

See also: Breast cancer management § Hormonal therapy

safety profile of the latter.[17] High-dose estrogen therapy was the standard of care for the palliative treatment of breast cancer in women up to the late 1970s or early 1980s.[18]

Estrogen dosages for breast cancer
Route/form Estrogen Dosage Ref(s)
Oral Estradiol 10 mg 3x/day
AI-resistant: 2 mg 1–3x/day		 [19][20]
[19][21]
Estradiol valerate AI-resistant: 2 mg 1–3x/day [19][21]
Conjugated estrogens 10 mg 3x/day [22][23][24][25]
Ethinylestradiol 0.5–1 mg 3x/day [23][19][26][25]
Diethylstilbestrol 5 mg 3x/day [23][27][28]
Dienestrol 5 mg 3x/day [26][25][28]
Dimestrol 30 mg/day [22][25][28]
Chlorotrianisene 24 mg/day [22][28]
SC injection
 Estradiol benzoate 5 mg 2–3x/week [26][29][27][30]
Estradiol dipropionate 5 mg 2–3x/week [26][27][31][30]
Estradiol valerate 30 mg 1x/2 weeks [29]
Polyestradiol phosphate 40–80 mg 1x/4 weeks [32][33]
Estrone 5 mg ≥3x/week [34]
Notes: (1) Only in women who are at least 5 years
postmenopausal.[19]
(2) Dosages are not necessarily equivalent.

Other uses

Infertility

Estrogens may be used in treatment of

uterine lining.[35][36]

Pregnancy support

Estrogens like diethylstilbestrol were formerly used in high doses to help support pregnancy.[37] However, subsequent research showed diethylstilbestrol to be ineffective as well as harmful.[37]

Lactation suppression

Estrogens can be used to suppress

blood clots.[39]

Tall stature

Estrogen has been used to induce growth attenuation in tall girls.[40]

Estrogen-induced growth attenuation was used as part of the controversial

developmentally disabled girl from growing to adult size.[41]

Acromegaly

Estrogens have been used to treat acromegaly.[42][43][44] This is because they suppress growth hormone-induced insulin-like growth factor 1 (IGF-1) production in the liver.[42][43][44]

Sexual deviance

modulator therapy.[45] Lower dosages of estrogens have also been used in combination with high-dose progestogen therapy in the treatment of sexual deviance in men.[45] High incidence of sexual dysfunction has similarly been associated with high-dose estrogen therapy in men treated with it for prostate cancer.[47]

Breast enhancement

See also: Estradiol (medication) § Breast enhancement

Estrogens are involved in

size of the breasts.[48][49][50][51][52] However, acute or temporary breast enlargement is a well-known side effect of estrogens, and increases in breast size tend to regress following discontinuation of treatment.[48][50][51] Aside from those without prior established breast development, evidence is lacking for a sustained increase in breast size with estrogens.[48][50][51]

Depression

Published 2019 and 2020 guidelines from the

postmenopausal women.[53][54] This suggests that there is a window of opportunity for effective treatment of depressive symptoms with estrogens.[53] Research on combined estrogen and progestogen therapy for depressive symptoms in the peri- and postmenopause is scarce and inconclusive.[53][54] Estrogens may augment the mood benefits of antidepressants in middle-aged and older women.[53][54] Menopausal hormone therapy is not currently approved for the treatment of depressive symptoms in the peri- or postmenopause in either the United States or the United Kingdom due to insufficient evidence of effectiveness.[53][54][58] More research is needed on the issue of estrogen therapy for depressive symptoms associated with menopause.[61][59]

Schizophrenia

Estrogens appear to be useful in the treatment of schizophrenia in both women and men.[64][65][66][67]

Acne

Systemic estrogen therapy at adequate doses is effective for and has been used in the treatment of acne in both females and males, but causes major side effects such as feminization and gynecomastia in males.[68][69][70][71][72][73][74][75]

Available forms

Major estrogens marketed for clinical or veterinary use
Generic name Class Brand name Route Intr.
Conjugated estrogens S/ester[a] Premarin PO, IM, TD, V 1941
Dienestrol[b] NS Synestrol[c] PO 1947
Diethylstilbestrol[b] NS Stilbestrol[c] PO, TD, V 1939
Esterified estrogens NS/ester[a] Estratab PO 1970
Estetrol[d] S Donesta[c] PO N/A
Estradiol S Estrace[c] PO, IM, SC, SL, TD, V 1935
Estradiol acetate S/ester Femring[c] PO, V 2001
Estradiol benzoate S/ester Progynon B IM 1933
Estradiol cypionate S/ester Depo-Estradiol IM 1952
Estradiol enanthate
 S/ester Deladroxate[c] IM 1970s
Estradiol valerate S/ester Progynon Depot[c] PO, IM 1954
Estramustine phosphate[e] S/ester Emcyt[c] PO 1970s
Estriol S Theelol[c] PO, V 1930
Estropipate[b] S/ester Ogen PO 1968
Ethinylestradiol S/alkyl Estinyl[c] PO, TD, V 1943
Fosfestrol[b] NS/ester Honvan[c] IM 1947
Hexestrol[b] NS Synestrol[c] PO, IM 1940s
Mestranol[b] S/alkyl/ether Enovid[c] PO 1957
Methylestradiol[b] S/alkyl Ginecosid[c] PO 1955
Polyestradiol phosphate[b] S/ester Estradurin IM 1957
Prasterone[f] Prohormone Intrarosa[c] PO, IM, V 1970s
Zeranol[g] NS Ralgro[c] PO 1970s
  1. ^ a b From equine sources
  2. ^ a b c d e f g h Limited availability
  3. ^ a b c d e f g h i j k l m n o p Has multiple other brand names
  4. ^ Not approved yet in humans; currently in phase III clinical trials
  5. chemotherapeutic agent
    , not as a hormone
  6. ^ Also known as dehydroepiandrosterone or DHEA
  7. ^ Veterinary use only

Estrogens that have been marketed come in two major types, steroidal estrogens and nonsteroidal estrogens.[1][76]

Steroidal estrogens

Progynon).[1]

17β-dihydroequilin sulfate.[1] A related and very similar product to conjugated estrogens, differing from it only in composition, is esterified estrogens.[1]

19-nortestosterone derivatives norethisterone, noretynodrel, and tibolone, metabolize into estrogens (e.g., ethinylestradiol) and can produce estrogenic effects as well.[1][79]

Nonsteroidal estrogens

Main article: Nonsteroidal estrogen

dienestrol acetate, diethylstilbestrol dipropionate, fosfestrol, hexestrol, and methestrol dipropionate. Chlorotrianisene, methallenestril, and doisynoestrol
are nonsteroidal estrogens structurally distinct from the stilbestrols that have also been used clinically. While used widely in the past, nonsteroidal estrogens have mostly been discontinued and are now rarely if ever used medically.

Contraindications

Estrogens have various contraindications.[80][81][82][83] An example is history of thromboembolism (blood clots).[80][81][82][83]

Side effects

The most common

reduced libido and erectile dysfunction), hypogonadism, testicular atrophy, and infertility
.

Estrogens can or may increase the risk of uncommon or rare but potentially serious issues including

hyperprolactinemia, prolactinoma, and dementia. These adverse effects are moderated by the concomitant use of a progestogen
, the type of progestogen used, and the dosage and route of estrogen used.

Around half of women with epilepsy who menstruate have a lowered seizure threshold around ovulation, most likely from the heightened estrogen levels at that time. This results in an increased risk of seizures in these women.

High doses of

hepatic protein synthesis than natural estrogens.[1][87][88][86][89] This is related to the fact that synthetic estrogens like ethinylestradiol are much more resistant to metabolism in the liver than natural estrogens.[1][90][89]

Side effects of lower versus higher dose oral estradiol
Serious adverse event EstradiolTooltip Estradiol_(medication) 6 mg/day (n = 34) EstradiolTooltip Estradiol_(medication) 30 mg/day (n = 32)
n % n %
Nausea/vomiting 0 0.0 5 15.6
Hyponatremia 1 2.9 5 15.6
Pleural effusion 0 0.0 4 12.5
Pain 6 17.6 4 12.5
Thrombosis/embolism 1 2.9 1 3.1
Brain ischemia 1 2.9 0 0.0
Infection 2 5.9 3 9.4
Hypercalcemia
 0 0.0 2 6.3
Other 6 17.6 10 31.3
Summary:
Side effects in a small phase 2 study of women with metastatic breast cancer randomized to receive either 6 or 30 mg/day of oral estradiol
Tooltip Pharmacokinetics_of_estradiol#Oral_administration as therapy. "The adverse event rate (≥grade 3) in the 30-mg group (11/32 [34%]; 95% confidence interval [CI], 23%-47%) was higher than in the 6-mg group (4/34 [18%]; 95% CI, 5%-22%; p=0.03). Clinical benefit rates were 9 of 32 (28%; 95% CI, 18%-41%) in the 30-mg group and 10 of 34 (29%; 95% CI, 19%-42%) in the 6-mg group." Sources: See template.

Long-term effects

Endometrial hyperplasia and cancer

Unopposed estrogen therapy stimulates the growth of the endometrium and is associated with a dramatically increased risk of endometrial hyperplasia and endometrial cancer in postmenopausal women.[91] The risk of endometrial hyperplasia is greatly increased by 6 months of treatment (ORTooltip odds ratio = 5.4) and further increased after 36 months of treatment (OR = 16.0).[91] This can eventually progress to endometrial cancer, and the risk of endometrial cancer similarly increases with duration of treatment (less than one year, RRTooltip relative risk = 1.4; many years (e.g., more than 10 years), RR = 15.0).[91] The risk of endometrial cancer also stays significantly elevated many years after stopping unopposed estrogen therapy, even after 15 years or more (RR = 5.8).[91]

Progestogens prevent the effects of estrogens on the endometrium.[91] As a result, they are able to completely block the increase in risk of endometrial hyperplasia caused by estrogen therapy in postmenopausal women, and are even able to decrease it below baseline (OR = 0.3 with continuous estrogen–progestogen therapy).[91] Continuous estrogen–progestogen therapy is more protective than sequential therapy, and a longer duration of treatment with continuous therapy is also more protective.[91] The increase in risk of endometrial cancer is similarly decreased with continuous estrogen–progestogen therapy (RR = 0.2–0.7).[91] For these reasons, progestogens are always used alongside estrogens in women who have intact uteruses.[91]

Cardiovascular events

Estrogens affect

venous thromboembolism (VTE), including of both deep vein thrombosis (DVT) and pulmonary embolism (PE).[1] Conversely, modern oral contraceptives are not associated with an increase in the risk of stroke and myocardial infarction (heart attack) in healthy, non-smoking premenopausal women of any age, except in those with hypertension (high blood pressure).[92][93] However, a small but significant increase in the risk of stroke, though not of myocardial infarction, has been found in menopausal women taking hormone replacement therapy.[94] An increase in the risk of stroke has also been associated with older high-dose oral contraceptives that are no longer used.[95]

Menopausal hormone therapy with replacement dosages of estrogens and progestogens has been associated with a significantly increased risk of cardiovascular events such as VTE.[96][97] However, such risks have been found to vary depending on the type of estrogen and the route of administration.[96][97] The risk of VTE is increased by approximately 2-fold in women taking oral estrogen for menopausal hormone therapy.[96][97] However, clinical research to date has generally not distinguished between conjugated estrogens and estradiol.[97] This is of importance because conjugated estrogens have been found to be more resistant to hepatic metabolism than estradiol and to increase clotting factors to a greater extent.[1] Only a few clinical studies have compared oral conjugated estrogens and oral estradiol.[97] Oral conjugated estrogens have been found to possess a significantly greater risk of thromboembolic and cardiovascular complications than oral estradiol (ORTooltip Odds ratio = 2.08) and oral esterified estrogens (ORTooltip Odds ratio = 1.78).[97][98][99] However, in another study, the increase in VTE risk with 0.625 mg/day oral conjugated estrogens plus medroxyprogesterone acetate and 1 or 2 mg/day oral estradiol plus norethisterone acetate was found to be equivalent (RRTooltip Relative risk = 4.0 and 3.9, respectively).[100][101] Other studies have found oral estradiol to be associated with an increase in risk of VTE similarly (RRTooltip Relative risk = 3.5 in one, ORTooltip odds ratio = 3.54 in first year of use in another).[97][102] As of present, there are no randomized controlled trials comparing oral conjugated estrogens and oral estradiol in terms of thromboembolic and cardiovascular risks that would allow for unambiguous conclusions, and additional research is needed to clarify this issue.[97][96] In contrast to oral estrogens as a group, transdermal estradiol at typical menopausal replacement dosages has not been found to increase the risk of VTE or other cardiovascular events.[96][94][97]

Both combined birth control pills (which contain ethinylestradiol and a progestin) and pregnancy are associated with about a 4-fold increase in risk of VTE, with the risk increase being slightly greater with the latter (OR = 4.03 and 4.24, respectively).[103] The risk of VTE during the postpartum period is 5-fold higher than during pregnancy.[103] Other research has found that the rate of VTE is 1 to 5 in 10,000 woman-years in women who are not pregnant or taking a birth control pill, 3 to 9 in 10,000 woman-years in women who are on a birth control pill, 5 to 20 in 10,000 women-years in pregnant women, and 40 to 65 in 10,000 women-years in postpartum women.[104] For birth control pills, VTE risk with high doses of ethinylestradiol (>50 μg, e.g., 100 to 150 μg) has been reported to be approximately twice that of low doses of ethinylestradiol (e.g., 20 to 50 μg).[92] As such, high doses of ethinylestradiol are no longer used in combined oral contraceptives, and all modern combined oral contraceptives contain 50 μg ethinylestradiol or less.[105][106] The absolute risk of VTE in pregnancy is about 0.5 to 2 in 1,000 (0.125%).[107]

Aside from type of estrogen and the route of administration, the risk of VTE with oral estrogen is also moderated by other factors, including the concomitant use of a progestogen, dosage, age, and smoking.[108][101] The combination of oral estrogen and a progestogen has been found to double the risk of VTE relative to oral estrogen alone (RRTooltip Relative risk = 2.05 for estrogen monotherapy, and RRTooltip relative risk = 2.02 for combined estrogen–progestogen therapy in comparison).[108] However, while this is true for most progestogens, there appears to be no increase in VTE risk relative to oral estrogen alone with the addition of oral progesterone or the atypical progestin dydrogesterone.[108][109][110] The dosage of oral estrogen appears to be important for VTE risk, as 1 mg/day oral estradiol increased VTE incidence by 2.2-fold while 2 mg/day oral estradiol increased VTE incidence by 4.5-fold (both in combination with norethisterone acetate).[101] The risk of VTE and other cardiovascular complications with oral estrogen–progestogen therapy increases dramatically with age.[108] In the oral conjugated estrogens and medroxyprogesterone acetate arm of the WHI, the risks of VTE stratified by age were as follows: age 50 to 59, RR = 2.27; age 60 to 69, RR = 4.28; and age 70 to 79, RR = 7.46.[108] Conversely, in the oral conjugated estrogens monotherapy arm of the WHI, the risk of VTE increased with age similarly but was much lower: age 50 to 59, RR = 1.22; age 60 to 69, RR = 1.3; and age 70 to 79, RR = 1.44.[108] In addition to menopausal hormone therapy, cardiovascular mortality has been found to increase considerably with age in women taking ethinylestradiol-containing combined oral contraceptives and in pregnant women.[111][112] In addition, smoking has been found to exponentially increase cardiovascular mortality in conjunction with combined oral contraceptive use and older age.[111][112] Whereas the risk of cardiovascular death is 0.06 per 100,000 in women who are age 15 to 34 years, are taking a combined oral contraceptive, and do not smoke, this increases by 50-fold to 3.0 per 100,000 in women who are age 35 to 44 years, are taking a combined oral contraceptive, and do not smoke.[111][112] Moreover, in women who do smoke, the risk of cardiovascular death in these two groups increases to 1.73 per 100,000 (29-fold higher relative to non-smokers) and 19.4 per 100,000 (6.5-fold higher relative to non-smokers), respectively.[111][112]

Although estrogens influence the hepatic production of coagulant and fibrinolytic factors and increase the risk of VTE and sometimes stroke, they also influence the liver synthesis of

arterial endothelium that is without severe lesions.[1]

Approximately 95% of orally ingested estradiol is inactivated during first-pass metabolism.[93] Nonetheless, levels of estradiol in the liver with oral administration are supraphysiological and approximately 4- to 5-fold higher than in circulation due to the first-pass.[1][113] This does not occur with parenteral routes of estradiol, such as transdermal, vaginal, or injection.[1] In contrast to estradiol, ethinylestradiol is much more resistant to hepatic metabolism, with a mean oral bioavailability of approximately 45%,[114] and the transdermal route has a similar impact on hepatic protein synthesis as the oral route.[115] Conjugated estrogens are also more resistant to hepatic metabolism than estradiol and show disproportionate effects on hepatic protein production as well, although not to the same magnitude as ethinylestradiol.[1] These differences are considered to be responsible for the greater risk of cardiovascular events with ethinylestradiol and conjugated estrogens relative to estradiol.[1]

High-dosage oral synthetic estrogens like diethylstilbestrol and ethinylestradiol are associated with fairly high rates of severe cardiovascular complications.

heart decompensation) has been observed with polyestradiol phosphate.[117][118][119]

surrogate marker for coagulation and VTE risk with estrogen therapy, although this topic has been debated.[120][121][122] SHBG levels with birth control pills containing different progestins are increased by 1.5 to 2-fold with levonorgestrel, 2.5- to 4-fold with desogestrel and gestodene, 3.5- to 4-fold with drospirenone and dienogest, and 4- to 5-fold with cyproterone acetate.[120] Contraceptive vaginal rings and contraceptive patches likewise have been found to increase SHBG levels by 2.5-fold and 3.5-fold, respectively.[120] Birth control pills containing high doses of ethinylestradiol (>50 μg) can increase SHBG levels by 5- to 10-fold, which is similar to the increase that occurs during pregnancy.[123] Conversely, increases in SHBG levels are much lower with estradiol, especially when used parenterally.[124][125][126][127][128] High-dose parenteral polyestradiol phosphate therapy has been found to increase SHBG levels by about 1.5-fold.[127]

Risk of venous thromboembolism (VTE) with hormone therapy and birth control (QResearch/CPRD)
Type Route Medications Odds ratio (95% CITooltip confidence interval)
Menopausal hormone therapy
 Oral Estradiol alone
    ≤1 mg/day
    >1 mg/day		 1.27 (1.16–1.39)*
1.22 (1.09–1.37)*
1.35 (1.18–1.55)*
Conjugated estrogens alone
    ≤0.625 mg/day
    >0.625 mg/day		 1.49 (1.39–1.60)*
1.40 (1.28–1.53)*
1.71 (1.51–1.93)*
Estradiol/medroxyprogesterone acetate 1.44 (1.09–1.89)*
Estradiol/dydrogesterone
    ≤1 mg/day E2
    >1 mg/day E2		 1.18 (0.98–1.42)
1.12 (0.90–1.40)
1.34 (0.94–1.90)
Estradiol/norethisterone
    ≤1 mg/day E2
    >1 mg/day E2		 1.68 (1.57–1.80)*
1.38 (1.23–1.56)*
1.84 (1.69–2.00)*
Estradiol/norgestrel or estradiol/drospirenone
 1.42 (1.00–2.03)
Conjugated estrogens/medroxyprogesterone acetate 2.10 (1.92–2.31)*
Conjugated estrogens/norgestrel
    ≤0.625 mg/day CEEs
    >0.625 mg/day CEEs		 1.73 (1.57–1.91)*
1.53 (1.36–1.72)*
2.38 (1.99–2.85)*
Tibolone alone 1.02 (0.90–1.15)
Raloxifene alone 1.49 (1.24–1.79)*
Transdermal
 Estradiol alone
   ≤50 μg/day
   >50 μg/day		 0.96 (0.88–1.04)
0.94 (0.85–1.03)
1.05 (0.88–1.24)
Estradiol/progestogen 0.88 (0.73–1.01)
Vaginal
 Estradiol alone 0.84 (0.73–0.97)
Conjugated estrogens alone 1.04 (0.76–1.43)
Combined birth control
 Oral Ethinylestradiol/norethisterone 2.56 (2.15–3.06)*
Ethinylestradiol/levonorgestrel 2.38 (2.18–2.59)*
Ethinylestradiol/norgestimate
 2.53 (2.17–2.96)*
Ethinylestradiol/desogestrel 4.28 (3.66–5.01)*
Ethinylestradiol/gestodene 3.64 (3.00–4.43)*
Ethinylestradiol/drospirenone 4.12 (3.43–4.96)*
Ethinylestradiol/cyproterone acetate 4.27 (3.57–5.11)*
Notes: (1)
Bioidentical progesterone was not included, but is known to be associated with no additional risk relative to estrogen alone. Footnotes: * = Statistically significant
(p < 0.01). Sources: See template.
Absolute and relative incidence of venous thromboembolism (VTE) during pregnancy and the postpartum period
Absolute incidence of first VTE per 10,000 person–years during pregnancy and the postpartum period
Swedish data A Swedish data B English data Danish data
Time period N Rate (95% CI) N Rate (95% CI) N Rate (95% CI) N Rate (95% CI)
Outside pregnancy 1105 4.2 (4.0–4.4) 1015 3.8 (?) 1480 3.2 (3.0–3.3) 2895 3.6 (3.4–3.7)
Antepartum 995 20.5 (19.2–21.8) 690 14.2 (13.2–15.3) 156 9.9 (8.5–11.6) 491 10.7 (9.7–11.6)
  Trimester 1 207 13.6 (11.8–15.5) 172 11.3 (9.7–13.1) 23 4.6 (3.1–7.0) 61 4.1 (3.2–5.2)
  Trimester 2 275 17.4 (15.4–19.6) 178 11.2 (9.7–13.0) 30 5.8 (4.1–8.3) 75 5.7 (4.6–7.2)
  Trimester 3 513 29.2 (26.8–31.9) 340 19.4 (17.4–21.6) 103 18.2 (15.0–22.1) 355 19.7 (17.7–21.9)
Around delivery 115 154.6 (128.8–185.6) 79 106.1 (85.1–132.3) 34 142.8 (102.0–199.8)
–
Postpartum 649 42.3 (39.2–45.7) 509 33.1 (30.4–36.1) 135 27.4 (23.1–32.4) 218 17.5 (15.3–20.0)
  Early postpartum 584 75.4 (69.6–81.8) 460 59.3 (54.1–65.0) 177 46.8 (39.1–56.1) 199 30.4 (26.4–35.0)
  Late postpartum 65 8.5 (7.0–10.9) 49 6.4 (4.9–8.5) 18 7.3 (4.6–11.6) 319 3.2 (1.9–5.0)
Incidence rate ratios (IRRs) of first VTE during pregnancy and the postpartum period
Swedish data A Swedish data B English data Danish data
Time period IRR* (95% CI) IRR* (95% CI) IRR (95% CI)† IRR (95% CI)†
Outside pregnancy
Reference (i.e., 1.00)
Antepartum 5.08 (4.66–5.54) 3.80 (3.44–4.19) 3.10 (2.63–3.66) 2.95 (2.68–3.25)
  Trimester 1 3.42 (2.95–3.98) 3.04 (2.58–3.56) 1.46 (0.96–2.20) 1.12 (0.86–1.45)
  Trimester 2 4.31 (3.78–4.93) 3.01 (2.56–3.53) 1.82 (1.27–2.62) 1.58 (1.24–1.99)
  Trimester 3 7.14 (6.43–7.94) 5.12 (4.53–5.80) 5.69 (4.66–6.95) 5.48 (4.89–6.12)
Around delivery 37.5 (30.9–44.45) 27.97 (22.24–35.17) 44.5 (31.68–62.54)
–
Postpartum 10.21 (9.27–11.25) 8.72 (7.83–9.70) 8.54 (7.16–10.19) 4.85 (4.21–5.57)
  Early postpartum 19.27 (16.53–20.21) 15.62 (14.00–17.45) 14.61 (12.10–17.67) 8.44 (7.27–9.75)
  Late postpartum 2.06 (1.60–2.64) 1.69 (1.26–2.25) 2.29 (1.44–3.65) 0.89 (0.53–1.39)
Notes: Swedish data A = Using any code for VTE regardless of confirmation. Swedish data B = Using only algorithm-confirmed VTE. Early postpartum = First 6 weeks after delivery. Late postpartum = More than 6 weeks after delivery. * = Adjusted for age and calendar year. † = Unadjusted ratio calculated based on the data provided. Source: [129]

Breast cancer

Estrogens are responsible for

high-dose estrogen therapy is effective in the treatment of breast cancer as well and has about the same degree of effectiveness as antiestrogen therapy, although it is far less commonly used due to adverse effects.[140][141] The usefulness of high-dose estrogen therapy in the treatment of ER-positive breast cancer is attributed to a bimodal effect in which high concentrations of estrogens signal breast cancer cells to undergo apoptosis, in contrast to lower concentrations of estrogens which stimulate their growth.[140][141]

A 2017

observational studies).[142] This was in accordance with a previous analysis of estrogen-only treatment with estradiol or conjugated estrogens which similarly found no increased risk (RR = 0.99).[142] Moreover, another study found that the risk of breast cancer with estradiol and conjugated estrogens was not significantly different (RR = 1.15 for conjugated estrogens versus estradiol).[142] These findings are paradoxical because oophorectomy in premenopausal women and antiestrogen therapy in postmenopausal women are well-established as considerably reducing the risk of breast cancer (RR = 0.208 to 0.708 for chemoprevention with antiestrogens in postmenopausal women).[137][138][139] However, there are indications that there may be a ceiling effect such that past a certain low concentration threshold (e.g., approximately 10.2 pg/mL for estradiol), additional estrogens alone may not further increase the risk of breast cancer in postmenopausal women.[143] There are also indications that the fluctuations in estrogen levels across the normal menstrual cycle in premenopausal women may be important for breast cancer risk.[144]

In contrast to estrogen-only therapy, combined estrogen and progestogen treatment, although dependent on the progestogen used, is associated with an increased risk of breast cancer.[142][145] The increase in risk is dependent on the duration of treatment, with more than five years (OR = 2.43) having a significantly greater risk than less than five years (OR = 1.49).[142] In addition, sequential estrogen–progestogen treatment (OR = 1.76) is associated with a lower risk increase than continuous treatment (OR = 2.90), which has a comparably much higher risk.[142] The increase in risk also differs according to the specific progestogen used.[142] Treatment with estradiol plus medroxyprogesterone acetate (OR = 1.19), norethisterone acetate (OR = 1.44), levonorgestrel (OR = 1.47), or a mixed progestogen subgroup (OR = 1.99) were all associated with an increased risk.[142] In a previous review, the increase in breast cancer risk was found to not be significantly different between these three progestogens.[142] Conversely, there is no significant increase in risk of breast cancer with bioidentical progesterone (OR = 1.00) or with the atypical progestin dydrogesterone (OR = 1.10).[142] In accordance, another study found similarly that the risk of breast cancer was not significantly increased with estrogen–progesterone (RRTooltip relative risk = 1.00) or estrogen–dydrogesterone (RR = 1.16) but was increased for estrogen combined with other progestins (RR = 1.69).[91] These progestins included chlormadinone acetate, cyproterone acetate, medrogestone, medroxyprogesterone acetate, nomegestrol acetate, norethisterone acetate, and promegestone, with the associations for breast cancer risk not differing significantly between the different progestins in this group.[91]

In contrast to cisgender women, breast cancer is extremely rare in men and transgender women treated with estrogens and/or progestogens, and gynecomastia or breast development in such individuals does not appear to be associated with an increased risk of breast cancer.

Klinefelter's syndrome, who have somewhat of a hybrid of a male and a female genotype (47,XXY), suggests that it may have to do with the sex chromosomes.[149][152][153]

Worldwide epidemiological evidence on breast cancer risk with menopausal hormone therapy (CGHFBC, 2019)
Therapy <5 years 5–14 years 15+ years
Cases
RRTooltip Adjusted relative risk (95% CI
Tooltip confidence interval) 		Cases
RRTooltip Adjusted relative risk (95% CI
Tooltip confidence interval) 		Cases
RRTooltip Adjusted relative risk (95% CI
Tooltip confidence interval)
Estrogen alone 1259 1.18 (1.10–1.26) 4869 1.33 (1.28–1.37) 2183 1.58 (1.51–1.67)
    By estrogen
        Conjugated estrogens 481 1.22 (1.09–1.35) 1910 1.32 (1.25–1.39) 1179 1.68 (1.57–1.80)
        Estradiol 346 1.20 (1.05–1.36) 1580 1.38 (1.30–1.46) 435 1.78 (1.58–1.99)
        Estropipate (estrone sulfate) 9 1.45 (0.67–3.15) 50 1.09 (0.79–1.51) 28 1.53 (1.01–2.33)
        Estriol 15 1.21 (0.68–2.14) 44 1.24 (0.89–1.73) 9 1.41 (0.67–2.93)
        Other estrogens 15 0.98 (0.46–2.09) 21 0.98 (0.58–1.66) 5 0.77 (0.27–2.21)
    By route
        Oral estrogens – – 3633 1.33 (1.27–1.38) – –
        
Transdermal
estrogens 		– – 919 1.35 (1.25–1.46) – –
        
Vaginal
estrogens 		– – 437 1.09 (0.97–1.23) – –
Estrogen and progestogen 2419 1.58 (1.51–1.67) 8319 2.08 (2.02–2.15) 1424 2.51 (2.34–2.68)
    By progestogen
        (Levo)norgestrel 343 1.70 (1.49–1.94) 1735 2.12 (1.99–2.25) 219 2.69 (2.27–3.18)
        Norethisterone acetate 650 1.61 (1.46–1.77) 2642 2.20 (2.09–2.32) 420 2.97 (2.60–3.39)
        Medroxyprogesterone acetate 714 1.64 (1.50–1.79) 2012 2.07 (1.96–2.19) 411 2.71 (2.39–3.07)
        Dydrogesterone 65 1.21 (0.90–1.61) 162 1.41 (1.17–1.71) 26 2.23 (1.32–3.76)
        Progesterone 11 0.91 (0.47–1.78) 38 2.05 (1.38–3.06) 1 –
        Promegestone 12 1.68 (0.85–3.31) 19 2.06 (1.19–3.56) 0 –
        Nomegestrol acetate 8 1.60 (0.70–3.64) 14 1.38 (0.75–2.53) 0 –
        Other progestogens 12 1.70 (0.86–3.38) 19 1.79 (1.05–3.05) 0 –
    By progestogen frequency
        
Continuous
 – – 3948 2.30 (2.21–2.40) – –
        
Intermittent
 – – 3467 1.93 (1.84–2.01) – –
Progestogen alone 98 1.37 (1.08–1.74) 107 1.39 (1.11–1.75) 30 2.10 (1.35–3.27)
    By progestogen
        Medroxyprogesterone acetate 28 1.68 (1.06–2.66) 18 1.16 (0.68–1.98) 7 3.42 (1.26–9.30)
        Norethisterone acetate 13 1.58 (0.77–3.24) 24 1.55 (0.88–2.74) 6 3.33 (0.81–13.8)
        Dydrogesterone 3 2.30 (0.49–10.9) 11 3.31 (1.39–7.84) 0 –
        Other progestogens 8 2.83 (1.04–7.68) 5 1.47 (0.47–4.56) 1 –
Miscellaneous
    Tibolone – – 680 1.57 (1.43–1.72) – –
Notes:
menopausal hormone therapy and breast cancer risk by the Collaborative Group on Hormonal Factors in Breast Cancer (CGHFBC). Fully adjusted relative risks
for current versus never-users of menopausal hormone therapy. Source: See template.
Risk of breast cancer with menopausal hormone therapy in large observational studies (Mirkin, 2018)
Study Therapy Hazard ratio (95% CITooltip confidence interval)
E3N-EPIC: Fournier et al. (2005) Estrogen alone 1.1 (0.8–1.6)
Estrogen plus progesterone
    Transdermal estrogen
    Oral estrogen		 0.9 (0.7–1.2)
0.9 (0.7–1.2)
No events
Estrogen plus progestin
    Transdermal estrogen
    Oral estrogen		 1.4 (1.2–1.7)
1.4 (1.2–1.7)
1.5 (1.1–1.9)
E3N-EPIC: Fournier et al. (2008) Oral estrogen alone 1.32 (0.76–2.29)
Oral estrogen plus progestogen
    Progesterone
    Dydrogesterone
    Medrogestone
    Chlormadinone acetate
    Cyproterone acetate
    Promegestone
    Nomegestrol acetate
    Norethisterone acetate
    Medroxyprogesterone acetate
Not analyzeda
0.77 (0.36–1.62)
2.74 (1.42–5.29)
2.02 (1.00–4.06)
2.57 (1.81–3.65)
1.62 (0.94–2.82)
1.10 (0.55–2.21)
2.11 (1.56–2.86)
1.48 (1.02–2.16)
Transdermal estrogen alone 1.28 (0.98–1.69)
Transdermal estrogen plus progestogen
    Progesterone
    Dydrogesterone
    Medrogestone
    Chlormadinone acetate
    Cyproterone acetate
    Promegestone
    Nomegestrol acetate
    Norethisterone acetate
    Medroxyprogesterone acetate
1.08 (0.89–1.31)
1.18 (0.95–1.48)
2.03 (1.39–2.97)
1.48 (1.05–2.09)
Not analyzeda
1.52 (1.19–1.96)
1.60 (1.28–2.01)
Not analyzeda
Not analyzeda
E3N-EPIC: Fournier et al. (2014) Estrogen alone 1.17 (0.99–1.38)
Estrogen plus progesterone or dydrogesterone 1.22 (1.11–1.35)
Estrogen plus progestin 1.87 (1.71–2.04)
CECILE: Cordina-Duverger et al. (2013) Estrogen alone 1.19 (0.69–2.04)
Estrogen plus progestogen
    Progesterone
    Progestins
        Progesterone derivatives
        Testosterone derivatives		 1.33 (0.92–1.92)
0.80 (0.44–1.43)
1.72 (1.11–2.65)
1.57 (0.99–2.49)
3.35 (1.07–10.4)
Footnotes: a = Not analyzed, fewer than 5 cases. Sources: See template.
Risk of breast cancer with menopausal hormone therapy by duration in large observational studies (Mirkin, 2018)
Study Therapy Hazard ratio (95% CITooltip confidence interval)
E3N-EPIC: Fournier et al. (2005)a Transdermal estrogen plus progesterone
    <2 years
    2–4 years
    ≥4 years
0.9 (0.6–1.4)
0.7 (0.4–1.2)
1.2 (0.7–2.0)
Transdermal estrogen plus progestin
    <2 years
    2–4 years
    ≥4 years
1.6 (1.3–2.0)
1.4 (1.0–1.8)
1.2 (0.8–1.7)
Oral estrogen plus progestin
    <2 years
    2–4 years
    ≥4 years
1.2 (0.9–1.8)
1.6 (1.1–2.3)
1.9 (1.2–3.2)
E3N-EPIC: Fournier et al. (2008) Estrogen plus progesterone
    <2 years
    2–4 years
    4–6 years
    ≥6 years
0.71 (0.44–1.14)
0.95 (0.67–1.36)
1.26 (0.87–1.82)
1.22 (0.89–1.67)
Estrogen plus dydrogesterone
    <2 years
    2–4 years
    4–6 years
    ≥6 years
0.84 (0.51–1.38)
1.16 (0.79–1.71)
1.28 (0.83–1.99)
1.32 (0.93–1.86)
Estrogen plus other progestogens
    <2 years
    2–4 years
    4–6 years
    ≥6 years
1.36 (1.07–1.72)
1.59 (1.30–1.94)
1.79 (1.44–2.23)
1.95 (1.62–2.35)
E3N-EPIC: Fournier et al. (2014) Estrogens plus progesterone or dydrogesterone
    <5 years
    ≥5 years
1.13 (0.99–1.29)
1.31 (1.15–1.48)
Estrogen plus other progestogens
    <5 years
    ≥5 years
1.70 (1.50–1.91)
2.02 (1.81–2.26)
Footnotes: a = Oral estrogen plus progesterone was not analyzed because there was a low number of women who used this therapy. Sources: See template.

Cholestatic hepatotoxicity

Estrogens, along with progesterone, can rarely cause

cholestatic hepatotoxicity, particularly at very high concentrations.[154][155][156] This is seen in intrahepatic cholestasis of pregnancy, which occurs in 0.4 to 15% of pregnancies (highly variable depending on the country).[157][158][159][160]

Gallbladder disease

Estrogen therapy has been associated with gallbladder disease, including risk of gallstone formation.[161][162][163][164] A 2017 systematic review and meta-analysis found that menopausal hormone therapy significantly increased the risk of gallstones (RR = 1.79) while oral contraceptives did not significantly increase the risk (RR = 1.19).[164] Biliary sludge appears in 5 to 30% of women during pregnancy, and definitive gallstones persisting postpartum become established in approximately 5%.[165]

Overdose

Estrogens are relatively safe in

overdose
and symptoms manifest mainly as reversible feminization.

Interactions

Inducers of cytochrome P450 enzymes like carbamazepine and phenytoin can accelerate the metabolism of estrogens and thereby decrease their bioavailability and circulating levels. Inhibitors of such enzymes can have the opposite effect and can increase estrogen levels and bioavailability.

Pharmacology

Pharmacodynamics

See also: Estrogen § Biological activity, and Pharmacodynamics of estradiol

Estrogens act as

subcutaneous injection in mice, estradiol is about 10-fold more potent than estrone and about 100-fold more potent than estriol.[166]

Estrogens have

antigonadotropic effects at sufficiently high concentrations via activation of the ER and hence can suppress the hypothalamic–pituitary–gonadal axis. This is caused by negative feedback, resulting in a suppression in secretion and decreased circulating levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The antigonadotropic effects of estrogens interfere with fertility and gonadal sex hormone production. They are responsible for the hormonal contraceptive effects of estrogens. In addition, they allow estrogens to act as functional antiandrogens by suppressing gonadal testosterone production. At sufficiently high doses, estrogens are able to suppress testosterone levels into the castrate range in men.[167]

Estrogens differ significantly in their pharmacological properties.[1][168][169] For instance, due to structural differences and accompanying differences in metabolism, estrogens differ from one another in their tissue selectivity; synthetic estrogens like ethinylestradiol and diethylstilbestrol are not inactivated as efficiently as estradiol in tissues like the liver and uterus and as a result have disproportionate effects in these tissues.[1] This can result in issues such as a relatively higher risk of thromboembolism.[1]

In-vitro pharmacodynamics

Affinities of estrogen receptor ligands for the ERα and ERβ
Ligand Other names
Relative binding affinities
(RBA, %)a
Absolute binding affinities
(Ki, nM)a		 Action
ERα
ERβ
ERα
ERβ
Estradiol E2; 17β-Estradiol 100 100 0.115 (0.04–0.24) 0.15 (0.10–2.08) Estrogen
Estrone E1; 17-Ketoestradiol 16.39 (0.7–60) 6.5 (1.36–52) 0.445 (0.3–1.01) 1.75 (0.35–9.24) Estrogen
Estriol E3; 16α-OH-17β-E2 12.65 (4.03–56) 26 (14.0–44.6) 0.45 (0.35–1.4) 0.7 (0.63–0.7) Estrogen
Estetrol E4; 15α,16α-Di-OH-17β-E2 4.0 3.0 4.9 19 Estrogen
Alfatradiol 17α-Estradiol 20.5 (7–80.1) 8.195 (2–42) 0.2–0.52 0.43–1.2 Metabolite
16-Epiestriol
 16β-Hydroxy-17β-estradiol 7.795 (4.94–63) 50 ? ? Metabolite
17-Epiestriol
 16α-Hydroxy-17α-estradiol 55.45 (29–103) 79–80 ? ? Metabolite
16,17-Epiestriol
 16β-Hydroxy-17α-estradiol 1.0 13 ? ? Metabolite
2-Hydroxyestradiol 2-OH-E2 22 (7–81) 11–35 2.5 1.3 Metabolite
2-Methoxyestradiol 2-MeO-E2 0.0027–2.0 1.0 ? ? Metabolite
4-Hydroxyestradiol 4-OH-E2 13 (8–70) 7–56 1.0 1.9 Metabolite
4-Methoxyestradiol 4-MeO-E2 2.0 1.0 ? ? Metabolite
2-Hydroxyestrone 2-OH-E1 2.0–4.0 0.2–0.4 ? ? Metabolite
2-Methoxyestrone 2-MeO-E1 <0.001–<1 <1 ? ? Metabolite
4-Hydroxyestrone 4-OH-E1 1.0–2.0 1.0 ? ? Metabolite
4-Methoxyestrone 4-MeO-E1 <1 <1 ? ? Metabolite
16α-Hydroxyestrone 16α-OH-E1; 17-Ketoestriol 2.0–6.5 35 ? ? Metabolite
2-Hydroxyestriol 2-OH-E3 2.0 1.0 ? ? Metabolite
4-Methoxyestriol 4-MeO-E3 1.0 1.0 ? ? Metabolite
Estradiol sulfate E2S; Estradiol 3-sulfate <1 <1 ? ? Metabolite
Estradiol disulfate Estradiol 3,17β-disulfate 0.0004 ? ? ? Metabolite
Estradiol 3-glucuronide E2-3G 0.0079 ? ? ? Metabolite
Estradiol 17β-glucuronide
 E2-17G 0.0015 ? ? ? Metabolite
Estradiol 3-gluc. 17β-sulfate E2-3G-17S 0.0001 ? ? ? Metabolite
Estrone sulfate E1S; Estrone 3-sulfate <1 <1 >10 >10 Metabolite
Estradiol benzoate EB; Estradiol 3-benzoate 10 ? ? ? Estrogen
Estradiol 17β-benzoate E2-17B 11.3 32.6 ? ? Estrogen
Estrone methyl ether Estrone 3-methyl ether 0.145 ? ? ? Estrogen
ent-Estradiol 1-Estradiol 1.31–12.34 9.44–80.07 ? ? Estrogen
Equilin 7-Dehydroestrone 13 (4.0–28.9) 13.0–49 0.79 0.36 Estrogen
Equilenin 6,8-Didehydroestrone 2.0–15 7.0–20 0.64 0.62 Estrogen
17β-Dihydroequilin 7-Dehydro-17β-estradiol 7.9–113 7.9–108 0.09 0.17 Estrogen
17α-Dihydroequilin 7-Dehydro-17α-estradiol 18.6 (18–41) 14–32 0.24 0.57 Estrogen
17β-Dihydroequilenin 6,8-Didehydro-17β-estradiol 35–68 90–100 0.15 0.20 Estrogen
17α-Dihydroequilenin 6,8-Didehydro-17α-estradiol 20 49 0.50 0.37 Estrogen
Δ8-Estradiol 8,9-Dehydro-17β-estradiol 68 72 0.15 0.25 Estrogen
Δ8-Estrone 8,9-Dehydroestrone 19 32 0.52 0.57 Estrogen
Ethinylestradiol EE; 17α-Ethynyl-17β-E2 120.9 (68.8–480) 44.4 (2.0–144) 0.02–0.05 0.29–0.81 Estrogen
Mestranol EE 3-methyl ether ? 2.5 ? ? Estrogen
Moxestrol RU-2858; 11β-Methoxy-EE 35–43 5–20 0.5 2.6 Estrogen
Methylestradiol 17α-Methyl-17β-estradiol 70 44 ? ? Estrogen
Diethylstilbestrol DES; Stilbestrol 129.5 (89.1–468) 219.63 (61.2–295) 0.04 0.05 Estrogen
Hexestrol Dihydrodiethylstilbestrol 153.6 (31–302) 60–234 0.06 0.06 Estrogen
Dienestrol Dehydrostilbestrol 37 (20.4–223) 56–404 0.05 0.03 Estrogen
Benzestrol (B2) – 114 ? ? ? Estrogen
Chlorotrianisene TACE 1.74 ? 15.30 ? Estrogen
Triphenylethylene TPE 0.074 ? ? ? Estrogen
Triphenylbromoethylene TPBE 2.69 ? ? ? Estrogen
Tamoxifen ICI-46,474 3 (0.1–47) 3.33 (0.28–6) 3.4–9.69 2.5 SERM
Afimoxifene 4-Hydroxytamoxifen; 4-OHT 100.1 (1.7–257) 10 (0.98–339) 2.3 (0.1–3.61) 0.04–4.8 SERM
Toremifene 4-Chlorotamoxifen; 4-CT ? ? 7.14–20.3 15.4 SERM
Clomifene MRL-41 25 (19.2–37.2) 12 0.9 1.2 SERM
Cyclofenil F-6066; Sexovid 151–152 243 ? ? SERM
Nafoxidine U-11,000A 30.9–44 16 0.3 0.8 SERM
Raloxifene – 41.2 (7.8–69) 5.34 (0.54–16) 0.188–0.52 20.2 SERM
Arzoxifene LY-353,381 ? ? 0.179 ? SERM
Lasofoxifene CP-336,156 10.2–166 19.0 0.229 ? SERM
Ormeloxifene Centchroman ? ? 0.313 ? SERM
Levormeloxifene 6720-CDRI; NNC-460,020 1.55 1.88 ? ? SERM
Ospemifene Deaminohydroxytoremifene 0.82–2.63 0.59–1.22 ? ? SERM
Bazedoxifene – ? ? 0.053 ? SERM
Etacstil GW-5638 4.30 11.5 ? ? SERM
ICI-164,384
 – 63.5 (3.70–97.7) 166 0.2 0.08 Antiestrogen
Fulvestrant ICI-182,780 43.5 (9.4–325) 21.65 (2.05–40.5) 0.42 1.3 Antiestrogen
Propylpyrazoletriol PPT 49 (10.0–89.1) 0.12 0.40 92.8 ERα agonist
16α-LE2 16α-Lactone-17β-estradiol 14.6–57 0.089 0.27 131 ERα agonist
16α-Iodo-E2 16α-Iodo-17β-estradiol 30.2 2.30 ? ? ERα agonist
Methylpiperidinopyrazole MPP 11 0.05 ? ? ERα antagonist
Diarylpropionitrile DPN 0.12–0.25 6.6–18 32.4 1.7 ERβ agonist
8β-VE2 8β-Vinyl-17β-estradiol 0.35 22.0–83 12.9 0.50 ERβ agonist
Prinaberel ERB-041; WAY-202,041 0.27 67–72 ? ? ERβ agonist
ERB-196 WAY-202,196 ? 180 ? ? ERβ agonist
Erteberel SERBA-1; LY-500,307 ? ? 2.68 0.19 ERβ agonist
SERBA-2 – ? ? 14.5 1.54 ERβ agonist
Coumestrol – 9.225 (0.0117–94) 64.125 (0.41–185) 0.14–80.0 0.07–27.0 Xenoestrogen
Genistein – 0.445 (0.0012–16) 33.42 (0.86–87) 2.6–126 0.3–12.8 Xenoestrogen
Equol – 0.2–0.287 0.85 (0.10–2.85) ? ? Xenoestrogen
Daidzein – 0.07 (0.0018–9.3) 0.7865 (0.04–17.1) 2.0 85.3 Xenoestrogen
Biochanin A – 0.04 (0.022–0.15) 0.6225 (0.010–1.2) 174 8.9 Xenoestrogen
Kaempferol – 0.07 (0.029–0.10) 2.2 (0.002–3.00) ? ? Xenoestrogen
Naringenin – 0.0054 (<0.001–0.01) 0.15 (0.11–0.33) ? ? Xenoestrogen
8-Prenylnaringenin 8-PN 4.4 ? ? ? Xenoestrogen
Quercetin – <0.001–0.01 0.002–0.040 ? ? Xenoestrogen
Ipriflavone – <0.01 <0.01 ? ? Xenoestrogen
Miroestrol – 0.39 ? ? ? Xenoestrogen
Deoxymiroestrol
 – 2.0 ? ? ? Xenoestrogen
β-Sitosterol
 – <0.001–0.0875 <0.001–0.016 ? ? Xenoestrogen
Resveratrol – <0.001–0.0032 ? ? ? Xenoestrogen
α-Zearalenol – 48 (13–52.5) ? ? ? Xenoestrogen
β-Zearalenol – 0.6 (0.032–13) ? ? ? Xenoestrogen
Zeranol α-Zearalanol 48–111 ? ? ? Xenoestrogen
Taleranol β-Zearalanol 16 (13–17.8) 14 0.8 0.9 Xenoestrogen
Zearalenone ZEN 7.68 (2.04–28) 9.45 (2.43–31.5) ? ? Xenoestrogen
Zearalanone ZAN 0.51 ? ? ? Xenoestrogen
Bisphenol A BPA 0.0315 (0.008–1.0) 0.135 (0.002–4.23) 195 35 Xenoestrogen
Endosulfan EDS <0.001–<0.01 <0.01 ? ? Xenoestrogen
Kepone
 Chlordecone 0.0069–0.2 ? ? ? Xenoestrogen
o,p'-DDT
 – 0.0073–0.4 ? ? ? Xenoestrogen
p,p'-DDT
 – 0.03 ? ? ? Xenoestrogen
Methoxychlor p,p'-Dimethoxy-DDT 0.01 (<0.001–0.02) 0.01–0.13 ? ? Xenoestrogen
HPTE Hydroxychlor; p,p'-OH-DDT 1.2–1.7 ? ? ? Xenoestrogen
Testosterone T; 4-Androstenolone <0.0001–<0.01 <0.002–0.040 >5000 >5000 Androgen
Dihydrotestosterone DHT; 5α-Androstanolone 0.01 (<0.001–0.05) 0.0059–0.17 221–>5000 73–1688 Androgen
Nandrolone 19-Nortestosterone; 19-NT 0.01 0.23 765 53 Androgen
Dehydroepiandrosterone DHEA; Prasterone 0.038 (<0.001–0.04) 0.019–0.07 245–1053 163–515 Androgen
5-Androstenediol
 A5; Androstenediol 6 17 3.6 0.9 Androgen
4-Androstenediol – 0.5 0.6 23 19 Androgen
4-Androstenedione
 A4; Androstenedione <0.01 <0.01 >10000 >10000 Androgen
3α-Androstanediol 3α-Adiol 0.07 0.3 260 48 Androgen
3β-Androstanediol 3β-Adiol 3 7 6 2 Androgen
Androstanedione 5α-Androstanedione <0.01 <0.01 >10000 >10000 Androgen
Etiocholanedione 5β-Androstanedione <0.01 <0.01 >10000 >10000 Androgen
Methyltestosterone 17α-Methyltestosterone <0.0001 ? ? ? Androgen
Ethinyl-3α-androstanediol
 17α-Ethynyl-3α-adiol 4.0 <0.07 ? ? Estrogen
Ethinyl-3β-androstanediol
 17α-Ethynyl-3β-adiol 50 5.6 ? ? Estrogen
Progesterone P4; 4-Pregnenedione <0.001–0.6 <0.001–0.010 ? ? Progestogen
Norethisterone NET; 17α-Ethynyl-19-NT 0.085 (0.0015–<0.1) 0.1 (0.01–0.3) 152 1084 Progestogen
Norethynodrel
 5(10)-Norethisterone 0.5 (0.3–0.7) <0.1–0.22 14 53 Progestogen
Tibolone 7α-Methylnorethynodrel 0.5 (0.45–2.0) 0.2–0.076 ? ? Progestogen
Δ4-Tibolone 7α-Methylnorethisterone 0.069–<0.1 0.027–<0.1 ? ? Progestogen
3α-Hydroxytibolone – 2.5 (1.06–5.0) 0.6–0.8 ? ? Progestogen
3β-Hydroxytibolone – 1.6 (0.75–1.9) 0.070–0.1 ? ? Progestogen
Footnotes: a = (1)
ERβ
proteins (except the ERβ values from Kuiper et al. (1997), which are rat ERβ). Sources: See template page.
Relative affinities of estrogens for steroid hormone receptors and blood proteins
Estrogen
Relative binding affinities
(%)
ERTooltip Estrogen receptor ARTooltip Androgen receptor PRTooltip Progesterone receptor GRTooltip Glucocorticoid receptor MRTooltip Mineralocorticoid receptor SHBGTooltip Sex hormone-binding globulin
CBG
Tooltip Corticosteroid binding globulin
Estradiol 100 7.9 2.6 0.6 0.13 8.7–12 <0.1
Estradiol benzoate ? ? ? ? ? <0.1–0.16 <0.1
Estradiol valerate 2 ? ? ? ? ? ?
Estrone 11–35 <1 <1 <1 <1 2.7 <0.1
Estrone sulfate 2 2 ? ? ? ? ?
Estriol 10–15 <1 <1 <1 <1 <0.1 <0.1
Equilin 40 ? ? ? ? ? 0
Alfatradiol 15 <1 <1 <1 <1 ? ?
Epiestriol 20 <1 <1 <1 <1 ? ?
Ethinylestradiol 100–112 1–3 15–25 1–3 <1 0.18 <0.1
Mestranol 1 ? ? ? ? <0.1 <0.1
Methylestradiol 67 1–3 3–25 1–3 <1 ? ?
Moxestrol 12 <0.1 0.8 3.2 <0.1 <0.2 <0.1
Diethylstilbestrol ? ? ? ? ? <0.1 <0.1
Notes: Reference
CBG
Tooltip Corticosteroid-binding globulin. Sources: See template.
Affinities and estrogenic potencies of estrogen esters and ethers at the estrogen receptors
Estrogen Other names
RBA
Tooltip Relative binding affinity (%)a 		REP (%)b
ER
ERα
ERβ
Estradiol E2 100 100 100
Estradiol 3-sulfate
 E2S; E2-3S ? 0.02 0.04
Estradiol 3-glucuronide E2-3G ? 0.02 0.09
Estradiol 17β-glucuronide
 E2-17G ? 0.002 0.0002
Estradiol benzoate EB; Estradiol 3-benzoate 10 1.1 0.52
Estradiol 17β-acetate E2-17A 31–45 24 ?
Estradiol diacetate EDA; Estradiol 3,17β-diacetate ? 0.79 ?
Estradiol propionate
 EP; Estradiol 17β-propionate 19–26 2.6 ?
Estradiol valerate EV; Estradiol 17β-valerate 2–11 0.04–21 ?
Estradiol cypionate EC; Estradiol 17β-cypionate ?c 4.0 ?
Estradiol palmitate Estradiol 17β-palmitate 0 ? ?
Estradiol stearate Estradiol 17β-stearate 0 ? ?
Estrone E1; 17-Ketoestradiol 11 5.3–38 14
Estrone sulfate E1S; Estrone 3-sulfate 2 0.004 0.002
Estrone glucuronide E1G; Estrone 3-glucuronide ? <0.001 0.0006
Ethinylestradiol EE; 17α-Ethynylestradiol 100 17–150 129
Mestranol EE 3-methyl ether 1 1.3–8.2 0.16
Quinestrol EE 3-cyclopentyl ether ? 0.37 ?
Footnotes: a =
ERβ. Both mammalian cells and yeast have the capacity to hydrolyze estrogen esters. c = The affinities of estradiol cypionate for the ERs are similar to those of estradiol valerate and estradiol benzoate (figure
). Sources: See template page.

In-vivo pharmacodynamics

Selected biological properties of endogenous estrogens in rats
Estrogen
RBA
Tooltip relative binding affinity (%)		 Uterine weight (%)
Uterotrophy
 LHTooltip Luteinizing hormone levels (%)
RBA
Tooltip relative binding affinity (%)
Control – 100 – 100 –
Estradiol (E2) 100 506 ± 20 +++ 12–19 100
Estrone (E1) 11 ± 8 490 ± 22 +++ ? 20
Estriol (E3) 10 ± 4 468 ± 30 +++ 8–18 3
Estetrol (E4) 0.5 ± 0.2 ? Inactive ? 1
17α-Estradiol 4.2 ± 0.8 ? ? ? ?
2-Hydroxyestradiol 24 ± 7 285 ± 8 +b 31–61 28
2-Methoxyestradiol 0.05 ± 0.04 101 Inactive ? 130
4-Hydroxyestradiol 45 ± 12 ? ? ? ?
4-Methoxyestradiol 1.3 ± 0.2 260 ++ ? 9
4-Fluoroestradiola 180 ± 43 ? +++ ? ?
2-Hydroxyestrone 1.9 ± 0.8 130 ± 9 Inactive 110–142 8
2-Methoxyestrone 0.01 ± 0.00 103 ± 7 Inactive 95–100 120
4-Hydroxyestrone 11 ± 4 351 ++ 21–50 35
4-Methoxyestrone 0.13 ± 0.04 338 ++ 65–92 12
16α-Hydroxyestrone 2.8 ± 1.0 552 ± 42 +++ 7–24 <0.5
2-Hydroxyestriol 0.9 ± 0.3 302 +b ? ?
2-Methoxyestriol 0.01 ± 0.00 ? Inactive ? 4
Notes: Values are mean ± SD or range. ER RBA =
endogenous
). b = Atypical uterotrophic effect which plateaus within 48 hours (estradiol's uterotrophy continues linearly up to 72 hours). Sources: See template.
Potencies of oral estrogens[data sources 1]
Compound Dosage for specific uses (mg usually)[a]
ETD[b] EPD[b] MSD[b] MSD[c] OID[c] TSD[c]
Estradiol (non-micronized) 30 ≥120–300 120 6 - -
Estradiol (micronized) 6–12 60–80 14–42 1–2 >5 >8
Estradiol valerate 6–12 60–80 14–42 1–2 - >8
Estradiol benzoate - 60–140 - - - -
Estriol ≥20 120–150[d] 28–126 1–6 >5 -
Estriol succinate - 140–150[d] 28–126 2–6 - -
Estrone sulfate 12 60 42 2 - -
Conjugated estrogens 5–12 60–80 8.4–25 0.625–1.25 >3.75 7.5
Ethinylestradiol 200 μg 1–2 280 μg 20–40 μg 100 μg 100 μg
Mestranol 300 μg 1.5–3.0 300–600 μg 25–30 μg >80 μg -
Quinestrol 300 μg 2–4 500 μg 25–50 μg - -
Methylestradiol - 2 - - - -
Diethylstilbestrol 2.5 20–30 11 0.5–2.0 >5 3
DES dipropionate - 15–30 - - - -
Dienestrol 5 30–40 42 0.5–4.0 - -
Dienestrol diacetate 3–5 30–60 - - - -
Hexestrol - 70–110 - - - -
Chlorotrianisene - >100 - - >48 -
Methallenestril - 400 - - - -
Sources and footnotes:
  1. ^ [170][171][172][173][174][175] [176][177][178][179] [180][181][182][183][184][185][186][187][188]
  1. ^ Dosages are given in milligrams unless otherwise noted.
  2. ^ a b c Dosed every 2 to 3 weeks
  3. ^ a b c Dosed daily
  4. ^ a b In divided doses, 3x/day; irregular and atypical proliferation.
Relative oral potencies of estrogens
Estrogen
HF
Tooltip Hot flashes		 VETooltip Vaginal epithelium UCaTooltip Urinary calcium FSHTooltip Follicle-stimulating hormone LHTooltip Luteinizing hormone HDLTooltip High-density lipoprotein-CTooltip Cholesterol SHBGTooltip Sex hormone-binding globulin
CBG
Tooltip Corticosteroid-binding globulin
AGT
Tooltip Angiotensinogen		 Liver
Estradiol 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0
Estrone ? ? ? 0.3 0.3 ? ? ? ? ?
Estriol 0.3 0.3 0.1 0.3 0.3 0.2 ? ? ? 0.67
Estrone sulfate ? 0.9 0.9 0.8–0.9 0.9 0.5 0.9 0.5–0.7 1.4–1.5 0.56–1.7
Conjugated estrogens 1.2 1.5 2.0 1.1–1.3 1.0 1.5 3.0–3.2 1.3–1.5 5.0 1.3–4.5
Equilin sulfate
 ? ? 1.0 ? ? 6.0 7.5 6.0 7.5 ?
Ethinylestradiol 120 150 400 60–150 100 400 500–600 500–600 350 2.9–5.0
Diethylstilbestrol ? ? ? 2.9–3.4 ? ? 26–28 25–37 20 5.7–7.5
Sources and footnotes
Notes: Values are ratios, with estradiol as standard (i.e., 1.0). Abbreviations: HF = Clinical relief of
liver proteins. Liver = Ratio of liver estrogenic effects to general/systemic estrogenic effects (hot flashes/gonadotropins
). Sources: See template.
Potencies and durations of natural estrogens by intramuscular injection
Estrogen Form Dose (mg) Duration by dose (mg)
EPD CICD
Estradiol Aq. soln. ? – <1 d
Oil soln. 40–60 – 1–2 ≈ 1–2 d
Aq. susp. ? 3.5 0.5–2 ≈ 2–7 d; 3.5 ≈ >5 d
Microsph. ? – 1 ≈ 30 d
Estradiol benzoate Oil soln. 25–35 – 1.66 ≈ 2–3 d; 5 ≈ 3–6 d
Aq. susp. 20 – 10 ≈ 16–21 d
Emulsion ? – 10 ≈ 14–21 d
Estradiol dipropionate Oil soln. 25–30 – 5 ≈ 5–8 d
Estradiol valerate Oil soln. 20–30 5 5 ≈ 7–8 d; 10 ≈ 10–14 d;
40 ≈ 14–21 d; 100 ≈ 21–28 d
Estradiol benz. butyrate Oil soln. ? 10 10 ≈ 21 d
Estradiol cypionate Oil soln. 20–30 – 5 ≈ 11–14 d
Aq. susp. ? 5 5 ≈ 14–24 d
Estradiol enanthate
 Oil soln. ? 5–10 10 ≈ 20–30 d
Estradiol dienanthate
 Oil soln. ? – 7.5 ≈ >40 d
Estradiol undecylate Oil soln. ? – 10–20 ≈ 40–60 d;
25–50 ≈ 60–120 d
Polyestradiol phosphate Aq. soln. 40–60 – 40 ≈ 30 d; 80 ≈ 60 d;
160 ≈ 120 d
Estrone Oil soln. ? – 1–2 ≈ 2–3 d
Aq. susp. ? – 0.1–2 ≈ 2–7 d
Estriol Oil soln. ? – 1–2 ≈ 1–4 d
Polyestriol phosphate Aq. soln. ? – 50 ≈ 30 d; 80 ≈ 60 d
Notes and sources
Notes: All
ovulation-inhibiting dose of estradiol undecylate
is 20–30 mg/month. Sources: See template.
Parenteral potencies and durations of nonsteroidal estrogens
Estrogen Form Major brand name(s) EPD (14 days) Duration
Diethylstilbestrol (DES) Oil solution Metestrol 20 mg 1 mg ≈ 2–3 days; 3 mg ≈ 3 days
Diethylstilbestrol dipropionate Oil solution Cyren B 12.5–15 mg 2.5 mg ≈ 5 days
Aqueous suspension ? 5 mg ? mg = 21–28 days
Dimestrol (DES dimethyl ether) Oil solution Depot-Cyren, Depot-Oestromon, Retalon Retard 20–40 mg ?
Fosfestrol (DES diphosphate)a Aqueous solution Honvan ? <1 day
Dienestrol diacetate Aqueous suspension Farmacyrol-Kristallsuspension 50 mg ?
Hexestrol dipropionate Oil solution Hormoestrol, Retalon Oleosum 25 mg ?
Hexestrol diphosphatea Aqueous solution Cytostesin, Pharmestrin, Retalon Aquosum ? Very short
Note: All by
intravenous injection
. Sources: See template.
Classification of estrogens and antiestrogens by receptor–estrogen complex retention
Class Examples RE complex retention Pharmacodynamic profile Uterine effects
Short-acting (a.k.a.
"weak" or "impeded")
16-Epiestriol • 17α-Estradiol • ent-Estradiol • 16-Ketoestradiol • Dimethylstilbestrol • meso-Butestrol
 Short (1–4 hours) Single or once-daily injections: partial agonist or antagonist Early responsesa
Implant or multiple injections per day:
full agonist
 Early and late responsesb
Long-acting A. Estradiol • Estrone • Ethinylestradiol • Diethylstilbestrol • Hexestrol Intermediate (6–24 hours) Single or once-daily injections: full agonist Early and late responses
B. Clomifene • Nafoxidine • Nitromifene • Tamoxifen Long (>24–48 hours) Single injection: agonist
Repeated injections: antagonist 		Early and late responses
Footnotes: a = Early responses occur after 0–6 hours and include
hyperemia, amino acid and nucleotide uptake, activation of RNA polymerases I and II, and stimulation of induced protein, among others. b = Late responses occur after 6–48 hours and include cellular hypertrophy and hyperplasia and sustained RNA polymerase I and II activity, among others. Sources: [189][190][191][192][193][194][195]

Pharmacokinetics

See also: Pharmacokinetics of estradiol

Estrogens can be administered via a variety of

elimination half-lives of estrogens vary by estrogen and route of administration. Estrogens are eliminated mainly by the kidneys via the urine
as conjugates.

Protein binding and metabolic clearance rates of estrogens
Compound
RBATooltip Relative binding affinity to
SHBG
Tooltip sex hormone-binding globulin (%)		 Bound to
SHBG (%)		 Bound to
albumin (%)		 Total
bound (%)
MCR
Tooltip Metabolic clearance rate
(L/day/m2)
17β-Estradiol 50 37 61 98 580
Estrone 12 16 80 96 1050
Estriol 0.3 1 91 92 1110
Estrone sulfate 0 0 99 99 80
17β-Dihydroequilin 30 ? ? ? 1250
Equilin 8 26 13 ? 2640
17β-Dihydroequilin sulfate
 0 ? ? ? 375
Equilin sulfate
 0 ? ? ? 175
Δ8-Estrone ? ? ? ? 1710
Notes: RBA for SHBG (%) is compared to 100% for testosterone. Sources: See template.
Estrogen metabolism in humans
The image above contains clickable links
Description: The
hydroxyl (–OH) groups
. Sources: See template page.

Chemistry

See also: List of estrogens
Structures of major endogenous estrogens
Chemical structures of major endogenous estrogens
Estrone (E1)
Estriol (E3)
The image above contains clickable links
Note the
hydroxyl (–OH) groups
: estrone (E1) has one, estradiol (E2) has two, estriol (E3) has three, and estetrol (E4) has four.

Estrogens can be grouped as steroidal or nonsteroidal. The steroidal estrogens are

equilin sulfate. Nonsteroidal estrogens belong predominantly to the stilbestrol group of compounds and include diethylstilbestrol and hexestrol
, among others.

parent estrogens. Examples include estradiol valerate and diethylstilbestrol dipropionate, which are prodrugs of estradiol and diethylstilbestrol, respectively. Estrogen esters with fatty acid esters have increased lipophilicity and a prolonged duration of action when administered by intramuscular or subcutaneous injection. Some estrogen esters, such as polyestradiol phosphate, polyestriol phosphate, and polydiethylstilbestrol phosphate, are in the form of polymers
.

Structural properties of selected estradiol esters
Estrogen Structure Ester(s) Relative
mol. weight		 Relative
E2 contentb		 log Pc
Position(s) Moiet(ies) Type Lengtha
Estradiol
– – – – 1.00 1.00 4.0
Estradiol acetate
C3
Ethanoic acid
 Straight-chain fatty acid 2 1.15 0.87 4.2
Estradiol benzoate
C3 Benzoic acid Aromatic fatty acid – (~4–5) 1.38 0.72 4.7
Estradiol dipropionate
C3, C17β
Propanoic acid
(×2)		 Straight-chain fatty acid 3 (×2) 1.41 0.71 4.9
Estradiol valerate
C17β
Pentanoic acid
 Straight-chain fatty acid 5 1.31 0.76 5.6–6.3
Estradiol benzoate butyrate
C3, C17β Benzoic acid, butyric acid Mixed fatty acid – (~6, 2) 1.64 0.61 6.3
Estradiol cypionate
C17β
Cyclopentylpropanoic acid
 Cyclic fatty acid – (~6) 1.46 0.69 6.9
Estradiol enanthate
C17β
Heptanoic acid
 Straight-chain fatty acid 7 1.41 0.71 6.7–7.3
Estradiol dienanthate
C3, C17β
Heptanoic acid
(×2)		 Straight-chain fatty acid 7 (×2) 1.82 0.55 8.1–10.4
Estradiol undecylate
C17β
Undecanoic acid
 Straight-chain fatty acid 11 1.62 0.62 9.2–9.8
Estradiol stearate
C17β
Octadecanoic acid
 Straight-chain fatty acid 18 1.98 0.51 12.2–12.4
Estradiol distearate
C3, C17β
Octadecanoic acid
(×2)		 Straight-chain fatty acid 18 (×2) 2.96 0.34 20.2
Estradiol sulfate
C3 Sulfuric acid Water-soluble conjugate – 1.29 0.77 0.3–3.8
Estradiol glucuronide
C17β Glucuronic acid Water-soluble conjugate – 1.65 0.61 2.1–2.7
Estramustine phosphated
C3, C17β Normustine, phosphoric acid Water-soluble conjugate – 1.91 0.52 2.9–5.0
Polyestradiol phosphatee
C3–C17β Phosphoric acid Water-soluble conjugate – 1.23f 0.81f 2.9g
Footnotes: a = Length of
hydrophobicity). Retrieved from PubChem, ChemSpider, and DrugBank. d = Also known as estradiol normustine phosphate. e = Polymer of estradiol phosphate (~13 repeat units
). f = Relative molecular weight or estradiol content per repeat unit. g = log P of repeat unit (i.e., estradiol phosphate). Sources: See individual articles.

History

Discontinued or no longer marketed estrogens
Generic name Class Brand name Route Intr.
Chlorotrianisene NS Tace[a] PO 1952
Conjugated estriol S/ester Emmenin[a] PO 1930
Diethylstilbestrol dipropionate NS/ester Synestrin[a] IM 1940s
Estradiol dipropionate S/ester Agofollin[a] IM 1939
Estrogenic substances S Amniotin[a] PO, IM, TD, V 1929
Estrone S Theelin[a] IM 1929
Ethinylestradiol sulfonate S/alkyl/ester Deposiston[a] PO 1978
Methallenestril NS/ether Vallestril PO 1950s
Moxestrol S/alkyl Surestryl PO 1970s
Polyestriol phosphate S/ester Triodurin[a] IM 1968
Quinestrol S/alkyl/ether Estrovis PO 1960s
  1. ^ a b c d e f g h Has multiple other brand names

pharmaceutical company Schering in 1928.[202][203][204][205][206][207][208][209] In 1929, Adolf Butenandt and Edward Adelbert Doisy independently isolated and purified estrone, the first estrogen to be discovered.[210] The estrogen preparations Amniotin (Squibb), Progynon (Schering), and Theelin (Parke-Davis) were all on the market by 1929,[196] and various additional preparations such as Emmenin, Folliculin, Menformon, Oestroform, and Progynon B, containing purified estrogens or mixtures of estrogens, were on the market by 1934.[197][211][212] Estrogens were originally known under a variety of different names including estrogens, estrins, follicular hormones, folliculins, gynecogens, folliculoids, and female sex hormones, among others.[213][211]

An estrogen patch was reportedly marketed by Searle in 1928,[214][215] and an estrogen nasal spray was studied by 1929.[216]

In 1938, British scientists obtained a patent on a newly formulated nonsteroidal estrogen, diethylstilbestrol (DES), that was cheaper and more powerful than the previously manufactured estrogens. Soon after, concerns over the side effects of DES were raised in scientific journals while the drug manufacturers came together to lobby for governmental approval of DES. It was only until 1941 when estrogen therapy was finally approved by the Food and Drug Administration (FDA) for the treatment of menopausal symptoms.[217] Conjugated estrogens (brand name Premarin) was introduced in 1941 and succeeded Emmenin, the sales of which had begun to drop after 1940 due to competition from DES.[218] Ethinylestradiol was synthesized in 1938 by Hans Herloff Inhoffen and Walter Hohlweg at Schering AG in Berlin[219][220][221][222][223] and was approved by the FDATooltip Food and Drug Administration in the U.S.Tooltip United States on 25 June 1943 and marketed by Schering as Estinyl.[224]

Micronized estradiol, via the oral route, was first evaluated in 1972,[225] and this was followed by the evaluation of vaginal and intranasal micronized estradiol in 1977.[226] Oral micronized estradiol was first approved in the United States under the brand name Estrace in 1975.[227]

Society and culture

Availability

See also: List of estrogens available in the United States

Estrogens are widely available throughout the world.[4]

Research

Male birth control

metabolic changes.[228] In addition, there is evidence that with long-term therapy, fertility and gonadal sex hormone production in men may not return following discontinuation of high-dose estrogen therapy.[230]

Eating disorders

Estrogen has been used as a treatment for women with bulimia nervosa, in addition to cognitive behavioral therapy, which is the established standard for treatment in bulimia cases. The estrogen research hypothesizes that the disease may be linked to a hormonal imbalance in the brain.[231]

Miscellaneous

Estrogens have been used in studies which indicate that they may be effective in the treatment of

traumatic liver injury.[232]

In humans and mice, estrogens promote wound healing.[233]

Estrogen therapy has been proposed as a potential treatment for

autism but clinical studies are needed.[234]

References

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  24. ^ "Premarin® (conjugated estrogens tablets, USP) FDA label" (PDF). 2003.
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    ISSN 0098-7484
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    ISBN 978-3-642-86140-6
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  31. ISSN 0002-9955
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  32. ^ "Estradurin® (polyestradiol phosphate) information and labels". Pharmanovia.
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  34. ^ "Estrone suspension FDA review" (PDF). 1979.
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    .
  47. S2CID 262018256
    . A favourable feature of flutamide therapy has been its lesser effect on libido and sexual potency; fewer than 20% of patients treated with flutamide alone reported such changes. In contrast, nearly all patients treated with oestrogens or estramustine phosphate reported loss of sexual potency. [...] In comparative therapeutic trials, loss of potency has occurred in all patients treated with stilboestrol or estramustine phosphate compared with 0 to 20% of those given flutamide alone (Johansson et al. 1987; Lund & Rasmussen 1988).
  48. ^
    ISBN 978-3-11-024568-4
    .
  49. ISBN 978-1-4020-5866-0
    .
  50. ^
    PMID 9610425
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  52. ISBN 978-3-13-357407-5
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    S2CID 198967172
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    PMID 26130315
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  62. S2CID 81770543
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  63. SSRN 3457416
  64. S2CID 40584474
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  65. S2CID 3452898
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  66. S2CID 43291520
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  67. S2CID 3391650
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  68. S2CID 145822633
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  69. PMID 14841085
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  70. PMID 14914180
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  71. PMID 13147544
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  72. PMID 13029903
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  73. PMID 14957675
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  76. PMID 16821162
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  77. ^ "Drospirenone/Estetrol - Mithra Pharmaceuticals - AdisInsight".
  78. ^
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  79. PMID 13942007
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  80. ^
    PMID 2215269
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  86. ^
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  87. PMID 15063479
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  88. S2CID 29182738
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  89. ^
    ISSN 0144-3615
    .
  90. S2CID 11212469
    .
  91. ^
    S2CID 21894200
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    PMID 27307386
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  104. ^ "FDA Drug Safety Communication: Updated information about the risk of blood clots in women taking birth control pills containing drospirenone". Food and Drug Administration. Archived from the original on 27 April 2019.
  105. ISBN 978-0-203-34732-4
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  106. ISBN 978-0-323-29738-7
    .
  107. S2CID 30535761
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  108. ^
    S2CID 3850275
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  109. PMID 23835005
    . Dydrogesterone did not increase the risk of VTE associated with oral estrogen (odds ratio (OR) 0.9, 95% CI 0.4–2.3). Other progestogens (OR 3.9, 95% CI 1.5–10.0) were found to further increase the risk of VTE associated with oral estrogen (OR 4.2, 95% CI 1.5–11.6).
  110. S2CID 45890629
    . The adjusted relative risk of developing a VTE tended to be lower for E/D users (OR 0.84; 95% CI 0.37–1.92) than for users of other HRT (OR 1.42; 95% CI 1.10–1.82), compared to non-users.
  111. ^
    PMID 9914611
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  112. ^
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  113. ISBN 978-1-4511-4847-3
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  114. PMID 23375353
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  115. ISBN 978-0-08-055309-2
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  116. ^
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  119. PMID 28667081
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  121. S2CID 20803995
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  123. ISBN 978-3-319-53298-1
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  154. PMID 23933920.{{cite journal}}: CS1 maint: DOI inactive as of March 2024 (link
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  155. PMID 11352118
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  160. S2CID 260312828. Archived from the original
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  173. ISBN 978-3-11-024568-4
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  175. ISBN 978-94-009-8195-9
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  176. ISBN 978-3-11-150424-7
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  179. ISSN 0172-777X
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  183. PMID 14902290
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  184. ISSN 0001-6349
    . There is no doubt that the conversion of the endometrium with injections of both synthetic and native estrogenic hormone preparations succeeds, but the opinion whether native, orally administered preparations can produce a proliferation mucosa changes with different authors. PEDERSEN-BJERGAARD (1939) was able to show that 90% of the folliculin taken up in the blood of the vena portae is inactivated in the liver. Neither KAUFMANN (1933, 1935), RAUSCHER (1939, 1942) nor HERRNBERGER (1941) succeeded in bringing a castration endometrium into proliferation using large doses of orally administered preparations of estrone or estradiol. Other results are reported by NEUSTAEDTER (1939), LAUTERWEIN (1940) and FERIN (1941); they succeeded in converting an atrophic castration endometrium into an unambiguous proliferation mucosa with 120–300 oestradiol or with 380 oestrone.
  185. ISBN 978-3-642-57636-2
    .
  186. ^ Martinez-Manautou J, Rudel HW (1966). "Antiovulatory Activity of Several Synthetic and Natural Estrogens". In Robert Benjamin Greenblatt (ed.). Ovulation: Stimulation, Suppression, and Detection. Lippincott. pp. 243–253.
  187. ISBN 978-3-642-49506-9
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  188. PMID 13370006
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  189. PMID 830547
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  190. PMID 400777
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  191. S2CID 9628572
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  192. ISBN 978-3-662-07635-4
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  193. PMID 6356176
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  196. ^
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  199. ISBN 978-1-4613-2157-6
    .
  200. ^
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    .
  201. ISBN 978-0-465-07259-0. When Allen and Doisy heard about the [Ascheim-Zondek test for the diagnosis of pregnancy], they realized there was a rich and easily handled source of hormones in urine from which they could develop a potent extract. [...] Allen and Doisy's research was sponsored by the committee, while that of their main rival, Adolt Butenandt (b. 1903) of the University of Gottingen was sponsored by a German pharmaceutical firm. In 1929, both terms announced the isolation of a pure crystal female sex hormone, estrone, in 1929, although Doisy and Allen did so two months earlier than Butenandt.27 By 1931, estrone was being commercially produced by Parke Davis in this country, and Schering-Kahlbaum in Germany. Interestingly, when Butenandt (who shared the Nobel Prize for chemistry in 1939) isolated estrone and analyzed its structure, he found that it was a steroid, the first hormone to be classed in this molecular family.[permanent dead link
    ]
  202. ISBN 978-3-642-30725-6
    . The first sex steroid used as pharmacological agent was Progynon, first sold by Schering AG in 1928. [...]
  203. ISBN 978-1-60980-062-8
    .
  204. ISBN 978-1-60917-326-5
    .
  205. doi:10.1016/S0021-9258(18)76871-3
    .
  206. ISBN 978-0-521-81481-2
    .
  207. S2CID 35945534
    .
  208. ^ Batisweiler, J. (1928). Placentaextrakt Progynon (Schering-Kahlbaum) bei Menstruationsstörungen und Kastrationsfolgen. Zbl. Gynäk, 2227-2232. Chicago
  209. ISBN 978-1-4832-2584-5
    .
  210. PMID 15940278
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  211. ^
    ISSN 0098-7484
    .
  212. S2CID 72668930
    .
  213. ISSN 0025-7125
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  214. PMID 16414329
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  215. PMID 12970259
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  216. ISSN 0098-7484
    .
  217. ^ Rothenberg, Carla J. (25 April 2005). "The Rise and Fall of Estrogen Therapy: The History of HRT" (PDF). Archived from the original (PDF) on 5 September 2006. Retrieved 27 October 2006.
  218. ISBN 978-0-7735-7145-7
    .
  219. S2CID 46648877
    .
  220. OCLC 543168
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  221. PMID 4098492
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  222. ISBN 0-471-89980-1
    .
  223. PMID 16389046
    .
  224. ^ FDA (2007). "Approval history: Estinyl (ethinyl estradiol) NDA 005292". search: Estinyl
  225. PMID 5023261
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  226. PMID 591620
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  227. ^ "Drugs@FDA: FDA-Approved Drugs".
  228. ^
    ISBN 978-3-642-60107-1
    .
  229. ^
    ISBN 978-1-59745-453-7
    . Estrogens are highly efficient inhibitors of the hypothalamic-hypophyseal-testicular axis (212–214). Aside from their negative feedback action at the level of the hypothalamus and pituitary, direct inhibitory effects on the testis are likely (215,216). [...] The histology of the testes [with estrogen treatment] showed disorganization of the seminiferous tubules, vacuolization and absence of lumen, and compartmentalization of spermatogenesis.
  230. ^
    ISBN 978-1-58112-412-5
    . Estrogens act primarily through negative feedback at the hypothalamic-pituitary level to reduce LH secretion and testicular androgen synthesis. [...] Interestingly, if the treatment with estrogens is discontinued after 3 yr. of uninterrupted exposure, serum testosterone may remain at castration levels for up to another 3 yr. This prolonged suppression is thought to result from a direct effect of estrogens on the Leydig cells.
  231. ^ Andersson G (9 January 2007). "Bulimia May Result from Hormonal Imbalance". Karolinska Institutet. Archived from the original on 20 February 2012. Retrieved 4 March 2008.
  232. PMID 17392161
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  233. ^ Oh DM, Phillips, TJ (2006). "Sex Hormones and Wound Healing". Wounds. 18 (1): 8–18.
  234. PMID 27789681
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Further reading

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Estrogen_(medication)&oldid=1218700141"