Estradiol decanoate (E2D), or estradiol decylate, also known as estradiol 17β-decanoate, is a synthetic steroidal

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 ...

and 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 estradio ...

– specifically, the 17β-

decanoate Capric acid, also known as decanoic acid or decylic acid, is a saturated fatty acid, medium-chain fatty acid (MCFA), and carboxylic acid. Its formula is CH3(CH2)8COOH. Salts and esters of decanoic acid are called caprates or decanoates. The ter ...

(decylate)

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 a ...

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 ...

– which was studied for use in

hormone replacement 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 ...

for ovariectomized women in the late 1970s but was never marketed. Oral estradiol decanoate 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 ...

at a dosage of 0.25 to 0.5 mg/day for 14 days has been studied in ovariectomized women and found to produce levels of

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 ...

and estradiol with a ratio of about 1:2 (0.5) to 1:1.7 (0.6). This is in contrast to oral micronized estradiol, which has an estrone to estradiol ratio of about 5:1 (an 8- to 10-fold difference in ratio relative to oral estradiol decanoate in oil). The normal ratio of estrone to estradiol in women is about 1:2 (0.5) in premenopausal women and about 2:1 in postmenopausal women. As such, oral estradiol decanoate in oil may provide a more physiological and favorable profile of estrone and estradiol levels than oral micronized estradiol. The improved estrone to estradiol ratio of oral estradiol decanoate in oil is likely related to absorption via the

intestinal 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 and ...

lymphatic system, which allows for bypassing 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 ...

. This is dependent on the

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, ...

decanoate ester of estradiol decanoate, and in accordance, oral estradiol decanoate not dissolved in oil has less or absent effects in rodents. Absorption of oral estradiol decanoate in oil via the lymphatic system is analogous to the case of 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 ...

in oil.

References

Abandoned drugs Decanoate esters Estradiol esters Synthetic estrogens {{Genito-urinary-drug-stub

See also

References