Any of a number of steroid hormones produced mainly by the ovaries, and in smaller amounts by the adrenal cortex, during estrus cycle (of which the main one is 17β-estradiol), and responsible for the development and maintenance of female secondary sexual characteristics. Their production is controlled by the leutinizing hormone (a glycoprotein produced by the pituitary gland). They inhibit ovulation by suppressing the secretion of the follicle-stimulating hormone (another glycoprotein produced by the same pituitary cells), and thus the reason why estrogen is a major compound in oral contraceptives.
See Adolescent growth spurt, Adrenal cortex, Adrenal medulla, Cholesterol, Estradiol, Glycoproteins, Hormones, Oxytocin, Pituitary gland, Progesterone, Prolactin, Secondary sexual characteristics, Steroid hormones, Testosterone