Estradiol undecylate (EU or E2U), also known as estradiol undecanoate and formerly sold under the brand names Delestrec and Progynon Depot 100 among others, is an

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...

medication which has been used in the treatment of

prostate cancer Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that su ...

in men. It has also been used as a part of

hormone therapy Hormone therapy or hormonal therapy is the use of hormones in medical treatment. Treatment with hormone antagonists may also be referred to as hormonal therapy or antihormone therapy. The most general classes of hormone therapy are oncologic ho ...

for

transgender women A trans woman or a transgender woman is a woman who was assigned male at birth. Trans women have a female gender identity, may experience gender dysphoria, and may transition; this process commonly includes hormone replacement therapy and so ...

. Although estradiol undecylate has been used in the past, it was discontinued and hence is no longer available. The medication has been given by injection into muscle usually once a month.

Side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

s of estradiol undecylate in men may include

breast tenderness Breast pain is the symptom of discomfort in either one or both breasts. Pain in both breasts is often described as ''breast tenderness'', is usually associated with the menstrual period and is not serious. Pain that involves only one part of a br ...

breast development Breast development, also known as mammogenesis, is a complex biological process in primates that takes place throughout a female's life. It occurs across several phases, including prenatal development, puberty, and pregnancy. At menopause, bre ...

, feminization,

sexual dysfunction Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction a ...

infertility Infertility is the inability of a person, animal or plant to reproduce by natural means. It is usually not the natural state of a healthy adult, except notably among certain eusocial species (mostly haplodiploid insects). It is the normal st ...

, fluid retention, and

cardiovascular The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...

issues. Estradiol undecylate is an

and hence is an

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ag ...

of the

estrogen receptor Estrogen receptors (ERs) are a group of proteins found inside cells. They are receptors that are activated by the hormone estrogen (17β-estradiol). Two classes of ER exist: nuclear estrogen receptors ( ERα and ERβ), which are members of the ...

, the

biological target A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets ...

s like

estradiol Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...

. It is an

estrogen ester An estrogen ester is an ester of an estrogen, most typically of estradiol but also of other estrogens such as estrone, estriol, and even nonsteroidal estrogens like diethylstilbestrol. Esterification renders estradiol into a prodrug of estradiol ...

and a very long-lasting

prodrug A prodrug is a medication or compound that, after intake, is metabolized (i.e., converted within the body) into a pharmacologically active drug. Instead of administering a drug directly, a corresponding prodrug can be used to improve how the dru ...

in the body. Because of this, it is considered to be a

natural Nature, in the broadest sense, is the physical world or universe. "Nature" can refer to the phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. Although humans ar ...

and

bioidentical Bioidentical hormone replacement therapy (BHRT), also known as bioidentical hormone therapy (BHT) or natural hormone therapy, is the use of hormones that are identical on a molecular level with endogenous hormones in hormone replacement therapy. ...

form of estrogen. An injection of estradiol undecylate has a duration of about 1 to 4 months. Estradiol undecylate was first described in 1953 and was introduced for medical use by 1956. It remained in use as late as the 2000s before being discontinued. Estradiol undecylate was marketed 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 ...

, but does not seem to have ever been available in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

. It was used for many years as a parenteral estrogen to treat prostate cancer in men, although it was not employed as often as

polyestradiol phosphate Polyestradiol phosphate (PEP), sold under the brand name Estradurin, is an estrogen medication which is used primarily in the treatment of prostate cancer in men. It is also used in women to treat breast cancer, as a component of hormone therapy ...

Medical uses

Estradiol undecylate has been used as a form of

high-dose estrogen High-dose estrogen (HDE) is a type of hormone therapy in which high doses of estrogens are given. When given in combination with a high dose of a progestogen, it has been referred to as pseudopregnancy. It is called this because the estrogen and p ...

therapy to treat

, but has since largely been superseded for this indication by newer agents with fewer

adverse effect An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a " side effect", when judged to be secondary to a main or therapeutic effect. The term compl ...

s (e.g.,

gynecomastia Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse ( ...

and

complications) like analogues and

nonsteroidal antiandrogen A nonsteroidal antiandrogen (NSAA) is an antiandrogen with a nonsteroidal chemical structure. They are typically selective and full or silent antagonists of the androgen receptor (AR) and act by directly blocking the effects of androgens like ...

s. It has been assessed for this purpose in a number of clinical studies. It has been used at a dosage of 100 mg every 3 to 4 weeks (or once a month) by

intramuscular injection Intramuscular injection, often abbreviated IM, is the injection of a substance into a muscle. In medicine, it is one of several methods for parenteral administration of medications. Intramuscular injection may be preferred because muscles hav ...

for this indication. Estradiol undecylate has been used to suppress

sex drive Libido (; colloquial: sex drive) is a person's overall sexual drive or desire for sexual activity. Libido is influenced by biological, psychological, and social factors. Biologically, the sex hormones and associated neurotransmitters that act up ...

sex offender A sex offender (sexual offender, sex abuser, or sexual abuser) is a person who has committed a sex crime. What constitutes a sex crime differs by culture and legal jurisdiction. The majority of convicted sex offenders have convictions for crim ...

s. It has been used for this indication at a dosage of 50 to 100 mg by intramuscular injection once every 3 to 4 weeks. Estradiol undecylate has also been used to treat

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or ...

in women. It has been used in

menopausal hormone therapy Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. These symptoms can include hot flashes, vaginal ...

as well, for instance in the treatment of

hot flash Hot flashes (also known as hot flushes) are a form of flushing, often caused by the changing hormone levels that are characteristic of menopause. They are typically experienced as a feeling of intense heat with sweating and rapid heartbeat, an ...

es and other

menopausal symptoms Menopause, also known as the climacteric, is the time in women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between the age of 47 and 54. Medical professionals often d ...

. Along with

estradiol valerate Estradiol valerate (EV), sold for use by mouth under the brand name Progynova and Primiwal E4 and for use by injection under the brand names Delestrogen and Progynon Depot among others, is an estrogen medication. It is used in hormone therapy fo ...

estradiol cypionate Estradiol cypionate (EC), sold under the brand name Depo-Estradiol among others, is an estrogen medication which is used in hormone therapy for menopausal symptoms and low estrogen levels in cis women, in hormone therapy for trans women, and in ...

, and

estradiol benzoate Estradiol benzoate (EB), sold under the brand name Progynon-B among others, is an estrogen medication which is used in hormone therapy for menopausal symptoms and low estrogen levels in women, in hormone therapy for transgender women, and in th ...

, estradiol undecylate has been used as an intramuscular estrogen in

feminizing hormone therapy Feminizing hormone therapy, also known as transfeminine hormone therapy, is hormone therapy and sex reassignment therapy to change the secondary sex characteristics of transgender people from masculine or androgynous to feminine. It is a co ...

for

. It has been used at doses of 100 to as much as 800 mg per month by intramuscular injection for this purpose.

Available forms

Estradiol undecylate was available as an oil solution for intramuscular injection provided in

ampoule An ampoule (also ampul and ampule) is a small sealed vial which is used to contain and preserve a sample, usually a solid or liquid. Ampoules are usually made of glass. Modern ampoules are most commonly used to contain pharmaceuticals and chem ...

s at a concentration of 100 mg/mL.

Contraindications

Contraindication In medicine, a contraindication is a condition that serves as a reason not to take a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of indication, which is a reason to use a certain tre ...

s of estrogens include

coagulation Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism ...

problems,

cardiovascular disease Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, hea ...

liver disease Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common. Signs and symptoms Some of the si ...

, and certain

hormone-sensitive cancer A hormone-sensitive cancer, or hormone-dependent cancer, is a type of cancer that is dependent on a hormone for growth and/or survival. Examples include breast cancer, which is dependent on estrogens like estradiol, and prostate cancer, which is ...

s such as

and

endometrial cancer Endometrial cancer is a cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most ...

, among others.

Side effects

Estradiol undecylate and its

side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

s have been evaluated for the treatment of advanced prostate cancer in a phase III international multicenter

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 t ...

headed by Jacobi and colleagues of the Department of Urology,

University of Mainz The Johannes Gutenberg University Mainz (german: Johannes Gutenberg-Universität Mainz) is a public research university in Mainz, Rhineland Palatinate, Germany, named after the printer Johannes Gutenberg since 1946. With approximately 32,000 stud ...

. The study consisted of 191 patients from 12 treatment centers, who were treated for 6 months with

s of either 100 mg/month estradiol undecylate (96 men) or 300 mg/week

cyproterone acetate Cyproterone acetate (CPA), sold alone under the brand name Androcur or with ethinylestradiol under the brand names Diane or Diane-35 among others, is an antiandrogen and progestin medication used in the treatment of androgen-dependent condition ...

(95 men). Findings for a subgroup of 42 men at the University of Mainz center were initially reported in 1978 and 1980. These men were age 51 to 84 years (mean 68 years), and men with pre-existing cardiovascular disease were excluded. A considerable incidence of cardiovascular complications was reported for the estradiol undecylate group (76%; 16/21 incidence total); there was a 67% (14/21) incidence of cardiovascular

morbidity A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

and a 9.5% (2/21) incidence of cardiovascular mortality. The cardiovascular morbidity in this group included

peripheral edema Peripheral edema is edema (accumulation of fluid causing swelling) in tissues perfused by the peripheral vascular system, usually in the lower limbs. In the most dependent parts of the body (those hanging distally), it may be called dependent ede ...

and

superficial thrombophlebitis Superficial thrombophlebitis is a thrombosis and inflammation of superficial veins which presents as a painful induration with erythema, often in a linear or branching configuration forming cords. Superficial thrombophlebitis is due to infla ...

(38%; 8/21),

coronary heart disease Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pl ...

(24%; 5/21), and a

deep vein thrombosis Deep vein thrombosis (DVT) is a type of venous thrombosis involving the formation of a blood clot in a deep vein, most commonly in the legs or pelvis. A minority of DVTs occur in the arms. Symptoms can include pain, swelling, redness, and enla ...

(4.8%; 1/21), while the cardiovascular mortality included a

myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which ma ...

(4.8%; 1/21) and a

pulmonary embolism Pulmonary embolism (PE) is a blockage of an artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream ( embolism). Symptoms of a PE may include shortness of breath, chest pain particularly upon breathin ...

(4.8%; 1/21). Eight of the cases of cardiovascular complications in the estradiol undecylate group, including the two deaths, were regarded as "severe". Conversely, no incidence of cardiovascular toxicity occurred in the cyproterone acetate comparison group (0%; 0/21). Other side effects of estradiol undecylate included

(100%; 21/21) and

erectile dysfunction Erectile dysfunction (ED), also called impotence, is the type of sexual dysfunction in which the penis fails to become or stay erect during sexual activity. It is the most common sexual problem in men.Cunningham GR, Rosen RC. Overview of ma ...

(90%; 19/21). The cardiovascular complications with estradiol undecylate in this relatively small study are in contrast to large and high-quality clinical studies of high-dose

and

transdermal Transdermal is a route of administration wherein active ingredients are delivered across the skin for systemic distribution. Examples include transdermal patches used for medicine delivery. The drug is administered in the form of a patch or ointme ...

for prostate cancer, in which minimal to no cardiovascular toxicity has been observed. An expanded report of 191 patients, which included the 42 patients from the University of Mainz center plus an additional 149 patients from 11 other centers, was published in 1982. The antitumor effectiveness of estradiol undecylate and cyproterone acetate in this study was equivalent. The rates of improvement, no response, and deterioration were 52%, 41%, and 7% in the estradiol undecylate group and 48%, 44%, and 8% in the cyproterone acetate group, respectively. However, the incidence of a selection of specific side effects, including gynecomastia,

, and edema, was significantly lower in the cyproterone acetate group than in the estradiol undecylate group (37% vs. 94%, respectively). Gynecomastia specifically occurred in 13% (12/96) of the patients in the cyproterone acetate group and 77% (73/95) of the patients in the estradiol undecylate group.

Erectile dysfunction Erectile dysfunction (ED), also called impotence, is the type of sexual dysfunction in which the penis fails to become or stay erect during sexual activity. It is the most common sexual problem in men.Cunningham GR, Rosen RC. Overview of ma ...

occurred in "essentially all" patients in both groups. Leg edema occurred in 18% (17/95) of the estradiol undecylate group and 4.2% (4/96) of the cyproterone acetate group, while the incidences of superficial thrombophlebitis and coronary heart disease both were not described. The incidence of

thrombosis Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (th ...

was 4.2% (4/95) in the estradiol undecylate group and 5.3% (5/96) in the cyproterone acetate group. There were five deaths in total, three in the estradiol undecylate group and two in the cyproterone acetate group. Two of the deaths in each of the treatment groups were due to

cardiovascular event Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, he ...

s, while the remaining death in the estradiol undecylate group was due to unknown causes. The similar rate of cardiovascular complications besides edema between estradiol undecylate and cyproterone acetate that was observed is in contrast to the initial 42-patient report and to findings with other estrogens, such as

diethylstilbestrol Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with ...

and

estramustine phosphate Estramustine phosphate (EMP), also known as estradiol normustine phosphate and sold under the brand names Emcyt and Estracyt, is a dual estrogen and chemotherapy medication which is used in the treatment of prostate cancer in men. It is taken ...

, which have been shown to possess significantly higher cardiovascular toxicity than cyproterone acetate. On the basis of the expanded study, the researchers concluded that cyproterone acetate was an "acceptable alternative" to estrogen therapy with estradiol undecylate, but with a "considerably more favorable" side-effect profile. After the completion of the initial expanded study, a 5-year extension trial primarily of the Ruhr University Bochum center subgroup, led by Tunn and colleagues, was conducted. In this study, the cyproterone acetate group was changed from intramuscular injections to 100 mg/day oral cyproterone acetate. Of the 39 patients in the study, the global 5-year survival rate was not significantly different between the estradiol undecylate and cyproterone acetate groups (24% and 26%, respectively). In patients without metastases, the 5-year survival rate was 51% in the cyproterone acetate group relative to 43% in the estradiol undecylate group, although the difference was not statistically significant. In terms of non-prostate cancer deaths, there were 5 in the CPA group and 6 in the EU group. The incidence of cardiovascular-related mortality was 3 deaths in the CPA group and 3 deaths in the EU group. The side effects of estradiol undecylate have also been studied and reported beyond the preceding clinical trial programme and for other patient populations, for instance women. Side effects during therapy with massive doses of estradiol undecylate (200mg three times per week, or 600mg per week and around 2,400mg per month total) in

postmenopausal Menopause, also known as the climacteric, is the time in women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between the age of 47 and 54. Medical professionals often d ...

women with

advanced breast cancer Metastatic breast cancer, also referred to as metastases, advanced breast cancer, secondary tumors, secondaries or stage IV breast cancer, is a stage of breast cancer where the breast cancer cells have spread to distant sites beyond the axillary l ...

have included

appetite loss Anorexia is a medical term for a loss of appetite. While the term in non-scientific publications is often used interchangeably with anorexia nervosa, many possible causes exist for a loss of appetite, some of which may be harmless, while others i ...

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of th ...

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenter ...

vaginal bleeding Vaginal bleeding is any expulsion of blood from the vagina. This bleeding may originate from the uterus, vaginal wall, or cervix. Generally, it is either part of a normal menstrual cycle or is caused by hormonal or other problems of the reproductiv ...

vaginal discharge Vaginal discharge is a mixture of liquid, cells, and bacteria that lubricate and protect the vagina. This mixture is constantly produced by the cells of the vagina and cervix, and it exits the body through the vaginal opening. The composition, amou ...

, nipple pigmentation,

breast pain Breast pain is the symptom of discomfort in either one or both breasts. Pain in both breasts is often described as ''breast tenderness'', is usually associated with the menstrual period and is not serious. Pain that involves only one part of a br ...

rash A rash is a change of the human skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, c ...

urinary incontinence Urinary incontinence (UI), also known as involuntary urination, is any uncontrolled leakage of urine. It is a common and distressing problem, which may have a large impact on quality of life. It has been identified as an important issue in geri ...

edema Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels tight, the area ma ...

drowsiness Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep ...

hypercalcemia Hypercalcemia, also spelled hypercalcaemia, is a high calcium (Ca2+) level in the blood serum. The normal range is 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L), with levels greater than 2.6 mmol/L defined as hypercalcem ...

, and local injection-site reactions. Like with other estrogens, treatment with estradiol undecylate has been found to produce

testicular A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testosteron ...

abnormalities and disturbances of

spermatogenesis Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubu ...

in men. In

, estradiol undecylate by intramuscular injection at extremely high doses (200–800mg/month) was associated with greater incidence of

hyperprolactinemia Hyperprolactinaemia is the presence of abnormally high levels of prolactin in the blood. Normal levels average to about 13 ng/mL in women, and 5 ng/mL in men, with an upper normal limit of serum prolactin levels being 15-25 ng/mL ...

(high prolactin levels) than

ethinylestradiol Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. In the past, EE was widely used for various indications such as the treatment of menopausal symptoms, gynecological disord ...

orally at a dose of 100μg/day (or about 3mg/month total) (rates of 40% and 16% for

prolactin Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pi ...

levels greater than 1,000mU/L, respectively). Switching from estradiol undecylate to ethinylestradiol resulted in a decrease in prolactin levels in many individuals. The preceding dosage of estradiol undecylate corresponds to much greater estrogenic exposure than the dosage of ethinylestradiol.

Cyproterone acetate Cyproterone acetate (CPA), sold alone under the brand name Androcur or with ethinylestradiol under the brand names Diane or Diane-35 among others, is an antiandrogen and progestin medication used in the treatment of androgen-dependent condition ...

was also used in combination with estrogen in the study.

Overdose

Estradiol undecylate has been used clinically at massive doses of as much as 800 to 2,400 mg per month by intramuscular injection, given in divided doses of 100 to 200 mg per injection two to three times per week. For purposes of comparison, a single 100 mg intramuscular injection of estradiol undecylate has been found to produce maximal estradiol levels of about 500 pg/mL.

Symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...

s of estrogen overdosage may include

bloating Abdominal bloating (or simply bloating) is a short-term disease that affects the gastrointestinal tract. Bloating is generally characterized by an excess buildup of gas, air or fluids in the stomach. A person may have feelings of tightness, pres ...

, increased weight, water retention,

heavy legs Heavy legs is a condition described as an unpleasant sensation of pain and heaviness in the lower limbs. Symptoms include legs feeling weighted, stiff, and tired. Heavy legs can be caused by a wide-ranging collection of disorders including but not ...

, and leg cramps. These side effects can be diminished by reducing the estrogen dosage.

Interactions

Inhibitor Inhibitor or inhibition may refer to: In biology * Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity * Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotra ...

s and inducers of

cytochrome P450 Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various co ...

may influence the

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run ...

of estradiol and by extension circulating estradiol levels.

Pharmacology

Pharmacodynamics

Esters of estradiol like estradiol undecylate are readily

hydrolyzed Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis ...

s of estradiol, but have an extended duration when administered in

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

via

due to a

depot Depot ( or ) may refer to: Places * Depot, Poland, a village * Depot Island, Kemp Land, Antarctica * Depot Island, Victoria Land, Antarctica * Depot Island Formation, Greenland Brands and enterprises * Maxwell Street Depot, a restaurant in ...

effect afforded by their

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, f ...

ester

moiety Moiety may refer to: Chemistry * Moiety (chemistry), a part or functional group of a molecule ** Moiety conservation, conservation of a subgroup in a chemical species Anthropology * Moiety (kinship), either of two groups into which a society is ...

. As prodrugs of estradiol, estradiol undecylate and other estradiol esters are estrogens. Estradiol undecylate is of about 62% higher

molecular weight A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bio ...

than estradiol due to the presence of its C17β undecylate ester. Because estradiol undecylate is a prodrug of estradiol, it is considered to be a

and

form of estrogen. The effects of estradiol undecylate on

cortisol Cortisol is a steroid hormone, in the glucocorticoid class of hormones. When used as a medication, it is known as hydrocortisone. It is produced in many animals, mainly by the '' zona fasciculata'' of the adrenal cortex in the adrenal g ...

, dehydroepiandrosterone sulfate,

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...

, and

sex hormone-binding globulin Sex hormone-binding globulin (SHBG) or sex steroid-binding globulin (SSBG) is a glycoprotein that binds to androgens and estrogens. When produced by the Sertoli cells in the seminiferous tubules of the testis, it has also been called androgen ...

levels as well as on the

hypothalamic–pituitary–adrenal axis The hypothalamic–pituitary–adrenal axis (HPA axis or HTPA axis) is a complex set of direct influences and feedback interactions among three components: the hypothalamus (a part of the brain located below the thalamus), the pituitary gland (a ...

have been studied in men with prostate cancer and compared with those of high-dose

therapy. The effects of estradiol undecylate on serum lipids and

ceruloplasmin Ceruloplasmin (or caeruloplasmin) is a ferroxidase enzyme that in humans is encoded by the ''CP'' gene. Ceruloplasmin is the major copper-carrying protein in the blood, and in addition plays a role in iron metabolism. It was first described in 1 ...

levels have been studied as well. Additionally, the influence of estradiol undecylate on SHBG levels and free testosterone fraction in women has been described.

Antigonadotropic activity

Testosterone levels with 300 mg per week cyproterone acetate and 100 mg per month estradiol undecylate by intramuscular injection

A phase III

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, diet ...

comparing high-dose intramuscular

(300 mg/week) and high-dose intramuscular estradiol undecylate (100 mg/month) in the treatment of prostate cancer found that estradiol undecylate suppressed testosterone levels into the

castrate Castration is any action, surgical, chemical, or otherwise, by which an individual loses use of the testicles: the male gonad. Surgical castration is bilateral orchiectomy (excision of both testicles), while chemical castration uses pharmace ...

range (< 50 ng/dL) within at least 3 months whereas testosterone levels with cyproterone acetate were significantly higher and above the castrate range even after 6 months of treatment. With estradiol undecylate, testosterone levels fell from 416 ng/dL to 38 ng/mL (–91%) after 3 months and to 29.6 ng/dL (–93%) after 6 months, whereas with cyproterone acetate, testosterone levels fell from 434 ng/dL to 107 ng/mL (–75%) at 3 months and to 102 ng/mL (–76%) at 6 months. In another study using the same dosages, estradiol undecylate suppressed testosterone levels by 97% while CPA suppressed them by 70%. In accordance, whereas estrogens are well-established as able to suppress testosterone levels into the castrate range at sufficiently high dosages,

progestogen Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the bod ...

s like cyproterone acetate on their own are able to decrease testosterone levels only up to an apparent maximum of around 70 to 80%. Besides effects on testosterone levels, the long-term effects of estradiol undecylate on testicular morphology in transgender women have been studied.

Pharmacokinetics

The

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 undecylate have been assessed limitedly in a few studies. Following a single

of 100 mg estradiol undecylate in oil, mean levels of estradiol were about 500 pg/mL a day after injection and about 340 pg/mL 14 days after injection in 4people. Levels of estradiol with intramuscular estradiol undecylate were reported to be very irregular and to vary by as much as 10-fold between individuals. In another study, following a single intramuscular injection of 32.2 mg estradiol undecylate, levels of estradiol peaked at around 400 pg/mL after 3 days and decreased from this peak to around 200 pg/mL after 6 days in 3postmenopausal women. In a repeated administration study of 100 mg per month estradiol undecylate in 14men with prostate cancer, estradiol levels at trough were about 560 pg/mL at 3 months and about 540 pg/mL at 6 months following initiation of therapy. In a larger follow-up of the study with 21men, estradiol levels at trough were about 36pg/mL at baseline, 486pg/mL at 3months, and 598pg/mL at 6months of therapy. In one further study, levels of estradiol in an unspecified number of postmenopausal women following a single injection of 100mg estradiol undecylate were said to be between 300pg/mL and 600pg/mL six days post-injection. Due to its more protracted duration, doses of estradiol undecylate that are typical of other estradiol esters produce only "subthreshold" estradiol levels, and for this reason, higher single doses of estradiol undecylate are necessary for similar effects. However, the relatively low levels of estradiol produced by lower doses of estradiol undecylate are favorable for menopausal replacement therapy. The duration of estradiol undecylate is markedly prolonged relative to that of

, and many other

estradiol ester This is a list of estrogen esters, or ester prodrugs of estrogens. It includes esters, as well as ethers, of steroidal estrogens like estradiol, estrone, and estriol and of nonsteroidal estrogens like the stilbestrols diethylstilbestrol and hexes ...

s. A single intramuscular injection of 10 to 12.5 mg estradiol undecylate has a duration of 40 to 60 days (~1–2 months) and of 25 to 50 mg estradiol undecylate has an estimated duration of effect of 2 to 4 months in postmenopausal women. A single intramuscular injection of 20 to 30 mg estradiol undecylate has been found to inhibit

ovulation Ovulation is the release of eggs from the ovaries. In women, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilize ...

when used as an estrogen-only injectable contraceptive in

premenopausal Menopause, also known as the climacteric, is the time in women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between the age of 47 and 54. Medical professionals often d ...

women for 1 to 3 months (mean 1.7 months) as well. When used at a higher dose of 100 mg per injection in men with prostate cancer, estradiol undecylate has been given usually once a month. After a single

subcutaneous injection Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion. A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, c ...

of estradiol undecylate in rats, its duration of effect was 80 days (about 2.5 months). Due to its very prolonged duration, estradiol undecylate has been described in general as a favorable alternative to estradiol

implant Implant can refer to: Medicine * Implant (medicine), or specifically: **Brain implant **Breast implant ** Buttock implant **Cochlear implant **Contraceptive implant **Dental implant ** Fetal tissue implant ** Implantable cardioverter-defibrillato ...

s. The

excretion Excretion is a process in which metabolic waste is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys, and skin. This is in contrast with secretion, where the substance may have specific tasks after ...

of estradiol undecylate has been studied as well. Estradiol undecylate has not been used via

oral administration Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are ...

. However, a closely related estradiol ester, estradiol decanoate (estradiol decylate), has been studied via the oral route, and has been found to possess significant oral

bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. Ho ...

, to produce relatively high estradiol levels of about 100 pg/mL after a single 0.5 mg oral dose and about 100 to 150 pg/mL with continuous 0.25 mg/day oral therapy, and to have a much higher estradiol-to-

estrone Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized ...

ratio than oral estradiol of about 2:1. It is thought that this is due to

absorption Absorption may refer to: Chemistry and biology *Absorption (biology), digestion **Absorption (small intestine) *Absorption (chemistry), diffusion of particles of gas or liquid into liquid or solid materials *Absorption (skin), a route by which s ...

of estradiol decanoate by the

lymphatic system The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoid ...

and a consequent partial bypass of

first-pass metabolism The first pass effect (also known as first-pass metabolism or presystemic metabolism) is a phenomenon of drug metabolism whereby the concentration of a drug, specifically when administered orally, is greatly reduced before it reaches the system ...

in the

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it i ...

and

intestine The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans an ...

s, which is similarly known to occur with oral

testosterone undecanoate Testosterone undecanoate, sold under the brand names Andriol and Aveed among others, is an androgen and anabolic steroid (AAS) medication that is used mainly in the treatment of low testosterone levels in men, including hormone therapy for tran ...

Chemistry

Estradiol undecylate is a

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 ...

estrane Estrane is a C18 steroid derivative, with a gonane core. ''Estrenes'' are estrane derivatives that contain a double bond, with an example being nandrolone. ''Estratrienes'' (estrins) are estrane derivatives that contain three double bonds, for i ...

steroid A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and ...

and an

. It is specifically the C17β undecylate (undecanoate)

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ...

. The compound is also known as estradiol 17β-undecylate or as estra-1,3,5(10)-triene-3,17β-diol 17β-undecanoate. The undecylic acid (undecanoic acid) ester of estradiol undecylate is a

medium-chain fatty acid Medium-chain triglycerides (MCTs) are triglycerides with two or three fatty acids having an aliphatic tail of 6–12 carbon atoms, i.e. medium-chain fatty acids (MCFAs). Rich food sources for commercial extraction of MCTs include palm kernel oil a ...

and is found naturally in many foods, some examples of which include

coconut The coconut tree (''Cocos nucifera'') is a member of the palm tree family (Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, the seed, or the f ...

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...

fat In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food. The term often refers specifically to triglycerides (triple est ...

s, and

rice Rice is the seed of the grass species '' Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima'' (African rice). The name wild rice is usually used for species of the genera '' Zizania'' and '' Porteresia'', both wild and domesticat ...

. Estradiol undecylate is a relatively long-chain ester of estradiol. Its undecylate ester contains 11

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon ma ...

atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, a ...

s. For comparison, the ester chains of

estradiol acetate Estradiol acetate (EA), sold under the brand names Femtrace, Femring, and Menoring, is an estrogen medication which is used in hormone therapy for the treatment of menopausal symptoms in women.https://www.accessdata.fda.gov/drugsatfda_docs/label/ ...

, and

estradiol enantate 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 ...

have 2, 5, and 7 carbon atoms, respectively. As a result of its longer ester chain, estradiol undecylate is the most

lipophilic Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipo ...

of these estradiol esters, and for this reason, has by far the longest duration when administered in oil solution by intramuscular injection. An example of an estradiol ester with a longer ester chain than estradiol undecylate is estradiol stearate (Depofollan), which has 18 carbon atoms and has been used in medicine as an estrogen as well. A few estradiol esters related to estradiol undecylate include estradiol decanoate,

estradiol diundecylate Estradiol diundecylate (brand name Estrolent), or estradiol diundecanoate, also known as 17β-estradiol 3,17β-diundecylate, is an estrogen and an estrogen ester – specifically, the 3,17β-di undecylate ester of estradiol – which has been ma ...

, and

estradiol diundecylenate Estradiol diundecylenate (brand name Etrosteron), or estradiol diundecenoate, also known as 17β-estradiol 3,17β-diundec-10-enoate, is a semisynthetic steroidal estrogen and an estrogen ester – specifically, the 3,17β-di undecylenate ester ...

. Estradiol undecylate shares the same undecylate ester as

, an

androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...

anabolic steroid Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects ...

and very long-lasting

testosterone ester This is a list of androgen esters, including esters (as well as ethers) of natural androgens like testosterone and dihydrotestosterone (DHT) and synthetic anabolic–androgenic steroids (AAS) like nandrolone (19-nortestosterone). Esters of nat ...

. Estradiol undecylate is one of the longest-chain

steroid ester A steroid ester is an ester of a steroid. They include androgen esters, estrogen esters, progestogen esters, and corticosteroid esters. Steroid esters may be naturally occurring/endogenous like DHEA sulfate or synthetic like estradiol valerate. E ...

s that has been in common medical use.

History

Estradiol undecylate was first described in the

scientific literature : ''For a broader class of literature, see Academic publishing.'' Scientific literature comprises scholarly publications that report original empirical and theoretical work in the natural and social sciences. Within an academic field, scie ...

, along with

and a variety of other

s, by Karl Junkmann of Schering AG in 1953. It was introduced for medical use via

by 1956.

Syntex Laboratorios Syntex SA (later Syntex Laboratories, Inc.) was a pharmaceutical company formed in Mexico City in January 1944 by Russell Marker, Emeric Somlo, and Federico Lehmann to manufacture therapeutic steroids from the Mexican yams called ''cab ...

applied for a

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

for estradiol undecylate in 1958, which was granted in 1961 and was given a priority date of 1957. Estradiol undecylate was introduced for medical use and was employed for decades, but was eventually discontinued. It remained in use in some countries as late as the 2000s.

Harry Benjamin Harry Benjamin (January 12, 1885 – August 24, 1986) was a German-American endocrinologist and sexologist, widely known for his clinical work with transgender people. Early life and career Benjamin was born in Berlin, and raised in a German ...

reported on the use of estradiol undecylate in

in his book ''The Transsexual Phenomenon'' in 1966 and in a literature review in the ''

Journal of Sex Research The ''Journal of Sex Research'' is a peer-reviewed academic journal covering the study of human sexuality and the field of sexology in general. It is published by Routledge on behalf of the Society for the Scientific Study of Sexuality. In 1963, th ...

'' in 1967.

Society and culture

Generic names

''Estradiol undecylate'' is the generic name of the drug and its and . It is also spelled in some publications as ''estradiol unducelate'' and is also known as ''estradiol undecanoate''. In

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

, it is known under a variety of spellings including as ''estradiolundecylat'', ''östradiolundecylat'', ''östradiolundezylat'', ''oestradiolundecylat'', ''oestradiolundezylat'', and others. Estradiol undecylate is known by its former developmental code names ''RS-1047'' and ''SQ-9993'' as well.

Brand names

The major brand name of estradiol undecylate is Progynon Depot 100. It has also been marketed under other brand names including Delestrec, Depogin, Estrolent, Oestradiol D, Oestradiol-Retard Theramex, and Primogyn Depot ,1 mg/ml among others.

Availability

Estradiol undecylate was available in the

(including in

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It ...

Monaco Monaco (; ), officially the Principality of Monaco (french: Principauté de Monaco; Ligurian: ; oc, Principat de Mónegue), is a sovereign city-state and microstate on the French Riviera a few kilometres west of the Italian region of Lig ...

, the

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

), and

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

. However, it has been discontinued and hence is no longer available.

Research

Estradiol undecylate was studied by Schering alone as an estrogen-only injectable contraceptive in premenopausal women at a dose of 20 to 30 mg once a month. It was effective, lacked

breast The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues. In females, it serves as the mammary gland, which produces and sec ...

and

thromboembolic Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thro ...

complications, lacked other

s besides

amenorrhea Amenorrhea is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding). Outside the reproductive years, there is absence of menses ...

, and prevented

for 1 to 3 months (mean 1.7 months) following a single dose. However, uterine growth of 1 to 2 cm was observed after one year, and

endometrial hyperplasia Endometrial hyperplasia is a condition of excessive proliferation of the cells of the endometrium, or inner lining of the uterus. Most cases of endometrial hyperplasia result from high levels of estrogens, combined with insufficient levels of t ...

was occasionally encountered. The preparation was not further developed as a form of birth control due to the risks of endometrial hyperplasia and

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

associated with long-term unopposed estrogen therapy. Estradiol undecylate, in combination with norethisterone enanthate (at doses of 5 to 10 mg and 50 to 70 mg, respectively), was studied by Schering as a

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 ...

in premenopausal women and was found to be effective and well- tolerated, but ultimately was not marketed for this use.

References

{{Estrogen receptor modulators Abandoned drugs Antigonadotropins Estradiol esters Hormonal antineoplastic drugs Phenols Prodrugs Prostate cancer Synthetic estrogens Undecanoate esters

Medical uses

Available forms

Contraindications

Side effects

Overdose

Interactions

Pharmacology

Pharmacodynamics

Antigonadotropic activity

Pharmacokinetics

Chemistry

History

Society and culture

Generic names

Brand names

Availability

Research

See also

References