Xenoestrogen
Xenoestrogens are clinically significant because they can mimic the effects of endogenous estrogen and thus have been implicated in precocious puberty and other disorders of the reproductive system.
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.