Xenoestrogen
Xenoestrogens are a type of xenohormone that imitates estrogen. They can be either synthetic or natural chemical compounds. Synthetic xenoestrogens include some widely used industrial compounds, such as PCBs, BPA, and phthalates, which have estrogenic effects on a living organism even though they differ chemically from the estrogenic substances produced internally by the endocrine system of any organism. Natural xenoestrogens include phytoestrogens which are plant-derived xenoestrogens. Because the primary route of exposure to these compounds is by consumption of phytoestrogenic plants, they are sometimes called "dietary estrogens". Mycoestrogens, estrogenic substances from fungi, are another type of xenoestrogen that are also considered mycotoxins.
Esterified estrogens
Esterified estrogens (EEs), sold under the brand names Estratab and Menest among others, is an estrogen medication which is used hormone therapy for menopausal symptoms and low sex hormone levels in women, to treat breast cancer in both women and men, and to treat prostate cancer in men. It is formulated alone or in combination with methyltestosterone. It is taken by mouth.
Side effects of EEs include nausea, breast tension, edema, and breakthrough bleeding among others. It is an estrogen, or an agonist of the estrogen receptors, the biological target of estrogens like estradiol. EEs are a prodrug mainly of estradiol and to a lesser extent of equilin.
EEs were introduced for medical use by 1970. They are available in only a few countries, such as Chile and the United States. They have also been marketed in Argentina and Switzerland in the past.