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.
Levonorgestrel
Levonorgestrel is a progestogen; that is, an agonist of the progesterone receptor (PR), the main biological target of the progestogen sex hormone progesterone. It is also a weak agonist of the androgen receptor (AR), the main biological target of the androgen sex hormone testosterone. Levonorgestrel has no other important hormonal activity, including no estrogenic, glucocorticoid, or antimineralocorticoid activity. The lack of significant mineralocorticoid or antimineralocorticoid activity with levonorgestrel is in spite of a relatively high affinity for the mineralocorticoid receptor of as much as 75% of that of aldosterone. Due to its progestogenic activity, levonorgestrel has antigonadotropic effects, and is able to suppress fertility and gonadal sex hormone production in both women and men.