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 from cholesterol and secreted mainly from the gonads, though they can also be formed from adrenal androgens in adipose tissue. Relative to estradiol, both estrone and estriol have far weaker activity as estrogens. Estrone can be converted into estradiol, and serves mainly as a precursor or metabolic intermediate of estradiol. It is both a precursor and metabolite of estradiol.
Methyltestosterone, sold under the brand names Android, Metandren, and Testred among others, is an androgen and anabolic steroid (AAS) medication which is used in the treatment of low testosterone levels in men, delayed puberty in boys, at low doses as a component of menopausal hormone therapy for menopausal symptoms like hot flashes, osteoporosis, and low sexual desire in women, and to treat breast cancer in women. It is taken by mouth or held in the cheek or under the tongue.
Equilin is a naturally occurring estrogen sex hormone found in horses as well as a medication. It is one of the estrogens present in the estrogen mixtures known as conjugated estrogens and esterified estrogens. CEEs is the most commonly used form of estrogen in hormone replacement therapy (HRT) for menopausal symptoms in the United States. Estrone sulfate is the major estrogen in CEEs while equilin sulfate is the second major estrogen in the formulation, present as about 25% of the total.
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 disorders, and certain hormone-sensitive cancers. It is usually taken by mouth but is also used as a patch and vaginal ring.
Esterified estrogens/methyltestosterone (EEs/MT), sold under brand names such as Covaryx, Eemt, Essian, Estratest, Menogen, and Syntest, is a hormonal preparation that combines esterified estrogens (EEs) with methyltestosterone (MT) in one tablet and is used in menopausal hormone therapy.
Estrone sulfate, also known as E1S, E1SO4 and estrone 3-sulfate, is a natural, endogenous steroid and an estrogen ester and conjugate.
Estriol succinate, sold under the brand name Synapause among others, is an estrogen medication which is used in the treatment of menopausal symptoms. It is taken by mouth, in through the vagina, and by injection.
Conjugated estrogens (CEs), or conjugated equine estrogens (CEEs), sold under the brand name Premarin among others, is an estrogen medication which is used in menopausal hormone therapy and for various other indications. It is a mixture of the sodium salts of estrogen conjugates found in horses, such as estrone sulfate and equilin sulfate. CEEs are available in the form of both natural preparations manufactured from the urine of pregnant mares and fully synthetic replications of the natural preparations. They are formulated both alone and in combination with progestins such as medroxyprogesterone acetate. CEEs are usually taken by mouth, but can also be given by application to the skin or vagina as a cream or by injection into a blood vessel or muscle.
Estradiol sulfate (E2S), or 17β-estradiol 3-sulfate, is a natural, endogenous steroid and an estrogen ester. E2S itself is biologically inactive, but it can be converted by steroid sulfatase into estradiol, which is a potent estrogen. Simultaneously, estrogen sulfotransferases convert estradiol to E2S, resulting in an equilibrium between the two steroids in various tissues. Estrone and E2S are the two immediate metabolic sources of estradiol. E2S can also be metabolized into estrone sulfate (E1S), which in turn can be converted into estrone and estradiol. Circulating concentrations of E2S are much lower than those of E1S. High concentrations of E2S are present in breast tissue, and E2S has been implicated in the biology of breast cancer via serving as an active reservoir of estradiol.
17β-Dihydroequilin is a naturally occurring estrogen sex hormone found in horses as well as a medication. As the C3 sulfate ester sodium salt, it is a minor constituent (1.7%) of conjugated estrogens. However, as equilin, with equilin sulfate being a major component of CEEs, is transformed into 17β-dihydroequilin in the body, analogously to the conversion of estrone into estradiol, 17β-dihydroequilin is, along with estradiol, the most important estrogen responsible for the effects of CEEs.
8,9-Dehydroestrone, or Δ8-estrone, also known as estra-1,3,5(10),8-tetraen-3-ol-17-one, is a naturally occurring estrogen found in horses which is closely related to equilin, equilenin, and estrone, and, as the 3-sulfate ester sodium salt, is a minor constituent (3.5%) of conjugated estrogens (Premarin). It produces 8,9-dehydro-17β-estradiol as an important active metabolite, analogously to conversion of estrone or estrone sulfate into estradiol. The compound was first described in 1997. In addition to 8,9-dehydroestrone and 8,9-dehydro-17β-estradiol, 8,9-dehydro-17α-estradiol is likely also to be present in conjugated estrogens, but has not been identified at this time.
8,9-Dehydroestradiol, or Δ8-17β-estradiol, also known as estra-1,3,5(10),8-tetraen-17β-ol-3-one, is a naturally occurring steroidal estrogen found in horses which is closely related to equilin, equilenin, and estradiol, and, as the 3-sulfate ester sodium salt, is a minor constituent of conjugated estrogens (Premarin). It is also an important active metabolite of 8,9-dehydroestrone, analogously to conversion of estrone or estrone sulfate into estradiol.
Estradiol (E2) is a medication and naturally occurring steroid hormone. It is an estrogen and is used mainly in menopausal hormone therapy and to treat low sex hormone levels in women. It is also used in hormonal birth control for women, in feminizing hormone therapy for transgender women, and in the treatment of hormone-sensitive cancers like prostate cancer in men and breast cancer in women, among other uses. Estradiol can be taken by mouth, held and dissolved under the tongue, as a gel or patch that is applied to the skin, in through the vagina, by injection into muscle or fat, or through the use of an implant that is placed into fat, among other routes.
An estrogen (E) is a type of medication which is used most commonly in hormonal birth control and menopausal hormone therapy, and as part of feminizing hormone therapy for transgender women. They can also be used in the treatment of hormone-sensitive cancers like breast cancer and prostate cancer and for various other indications. Estrogens are used alone or in combination with progestogens. They are available in a wide variety of formulations and for use by many different routes of administration. Examples of estrogens include bioidentical estradiol, natural conjugated estrogens, synthetic steroidal estrogens like ethinylestradiol, and synthetic nonsteroidal estrogens like diethylstilbestrol. Estrogens are one of three types of sex hormone agonists, the others being androgens/anabolic steroids like testosterone and progestogens like progesterone.
Estrone (E1), sold under the brand names Estragyn, Kestrin, and Theelin among many others, is an estrogen medication and naturally occurring steroid hormone which has been used in menopausal hormone therapy and for other indications. It has been provided as an aqueous suspension or oil solution given by injection into muscle and as a vaginal cream applied inside of the vagina. It can also be taken by mouth as estradiol/estrone/estriol and in the form of prodrugs like estropipate and conjugated estrogens.
Estrone sulfate (E1S) is an estrogen medication and naturally occurring steroid hormone. It is used in menopausal hormone therapy among other indications. As the sodium salt, it is the major estrogen component of conjugated estrogens (Premarin) and esterified estrogens. In addition, E1S is used on its own as the piperazine salt estropipate. The compound also occurs as a major and important metabolite of estradiol and estrone. E1S is most commonly taken by mouth, but in the form of Premarin can also be taken by parenteral routes such as transdermal, vaginal, and injection.
Equine estrogens, or horse estrogens, are estrogens found in horses. They include the following:
The pharmacology of estradiol, an estrogen medication and naturally occurring steroid hormone, concerns its pharmacodynamics, pharmacokinetics, and various routes of administration.
Conjugated estriol, sold under the brand names Progynon and Emmenin, is an estrogen medication which was previously used for estrogen-type indications such as the treatment of menopausal symptoms in women. The term specifically refers to formulations of estriol conjugates which were manufactured from the estrogen-rich urine of pregnant women and were used as medications in the 1920s and 1930s. Conjugated estriol is analogous to and was superseded by conjugated estrogens, which is manufactured from the urine of pregnant mares. Conjugated estriol was among the first forms of pharmaceutical estrogen to be used in medicine. It was taken by mouth.
