ESTROGEN

FEMALE ESTROGEN

There are three estrogens found in human females. The amounts vary dependent on genetic makeup, age, body fat, lifestyle, pregnancy, medical condition.

17- BETA ESTRADIOL (E2)
This is the predominant natural human estrogen produced by the ovary prior to menopause. It is the primary biologically active estrogen at cell surface receptor sites and also inside the cell at the nucleus receptor sites. it is the major functioning estrogen for our bodies from puberty until menopause, and it is the one responsible for over four hundred functions in the female body. After menopause we lose the ovary source of 17-beta estradiol, and other body tissues cant make up for this loss of the most active form of the hormone. We are left with only the estrone made in the fat tissue as a poor substitute.
Losing the 17-beta estradiol results in the postmenopausal changes in the skin, bone, hair, heart, blood vessels, brain and other organs. Ideally if you decide to take estrogen therapy after menopause you would choose a form of 17-beta estradiol to provide exactly the same chemical molecule your ovary had previously made.
Brands include, Estrace tablets, Climara Patch, Vivelle Dot (uk = Estradot), Estrogel (uk= Oestrogel)
Even though some of these have been around for a very long time, most women and doctors have still only herd of Premarin. There is some 17-Beta Estradiol in Premarin, but a small amount in comparison to the other ingredients.

ESTRONE (E1)
This is the main estrogen found in postmenopausal women. Before menopause, estrone is made by the ovary, body fat, the adrenal glands and the liver. Estrone can be made from Estradiol and Estradiol can be made from Estrone.
Estrone is like a storage tank ready to convert to Estradiol when the body needs it. However it is usually converted to Estradiol by the functioning ovaries. Estrone continues to be made by the liver and body fat, and adrenal glands, after menopause. The more body fat a woman has, the more estrone she has.
Premarin has a high level of Estrone.

ESTRIOL (E3)
This is the weakest of the human estrogens. It is made by the placenta during pregnancy. Estriol is not normally present in non pregnant women.
BHRT doctors like to use this estrogen in the form of Bi-est (80% estriol, 20% estradiol) as it is thought to be the safer estrogen, protecting against breast cancer when a woman is pregnant.
Estriol does not provide the degree of protection on bone, heart, brain that Estradiol does.
Estriol can relieve the milder symptoms of menopause e.g vaginal dryness.


EQUINE ESTROGENS
Extracted form the urine of pregnant mares to make 'conjugated equine estrogens', the most common brand being PREMARIN PREgnant MARes urINe.
The pregnant mares are confined in inhumane ways during the period of urine collection, and their foals sold for slaughter.
The equine estrogens refer to about ten or more molecules that have different 'attachment strengths' for the estradiol receptor sites. Since the equine estrogens have several components that attach more strongly to the estradiol receptor tan does human estradiol, and some of the equine estrogens stay in the body far longer than does estradiol (up to 2-3 months) it makes sense to be very wary of this type of Estrogen.

PHYTOESTROGENS
These are estrogenic compounds found in several hundred different plants, including soybeans and red clover.
Phytoestrogens are biologically weaker than the native human estrogens, and have quite a range of activity at the human estrogen receptors, varying from pure agonist to mixed agonist-antagonist, to full antagonist effects. Some of these are dose and concentration related, and others are related to small chemical changes in the mollecular configuration of the molecules. These potency differences may help to explain the apparent discrepancy in reports that in China and Japan, where diets are high in phyto-estrogens and herbal sources of estrogen are widely used, women do not typically describe hot flashes but do continue to have bone loss after menopause. Japanese menopause researchers have shown clearly that there is an epidemic of osteoporosis in their country; their research indicates that phytoestrogens alone do not provide enough estrogen effect to prevent against osteoporosis and decline in cognitive function, even though the plant sources may be helpful for mild symptoms.

Phytoestrogens form soy and wild yam are used in the pharmaceutical industry as the precursor molecules for producing 17-beta estradiol to use in tablets, patches, and creams. All of the phytoestrogen precursors require chemical conversion in the laboratory to make the bioidentical human form of 17- beta estradiol, since the human body does not have the enzymes needed for these changes. So just taking a phytoestrogen supplement will not provide you with Estradiol.

XENOESTROGENS
A group of synthetic, organo-solvent, pesticide, and other compounds that mimic some of the actions of estrogens in humans but are not native to the human body and also produce toxic effects.
These chemicals are not normally found in nature, and are responsible for a great deal of environmental damage to animals, plants, and water sources.
Their estrogenic effects are generally negative and potentially carcinogenic.