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.
Estrogen (medication)
High-dose estrogen therapy is effective in suppressing spermatogenesis and fertility in men, and hence as a male contraceptive. It works both by strongly suppressing gonadotropin secretion and gonadal testosterone production and via direct effects on the testes. After a sufficient course of therapy, only Sertoli cells and spermatogonia remain in the seminiferous tubules of the testes, with a variety of other testicular abnormalities observable. The use of estrogens for contraception in men is precluded by major side effects such as sexual dysfunction, feminization, gynecomastia, and metabolic changes. In addition, there is evidence that with long-term therapy, fertility and gonadal sex hormone production in men may not return following discontinuation of high-dose estrogen therapy.