ATC Group: G03CA Natural and semisynthetic estrogens, plain

Estradiol, is chemically and biologically identical to endogenous human estradiol. It substitutes for the loss of oestrogen production in menopausal women, and alleviates menopausal symptoms. Oestrogens prevent bone loss following menopause or ovariectomy.

Estriol is a steroid, a weak estrogen, specifically an agonist of the estrogen receptors ERα and ERβ. It is one of three major endogenous estrogens, the others being estradiol and estrone.

The active ingredients of conjugated estrogens are primarily the sulfate esters of estrone, equilin sulfates, 17α-estradiol and 17β-estradiol. These substitute for the loss of estrogen production in menopausal women, and alleviate menopausal symptoms. Estrogens prevent bone loss following menopause or ovariectomy.

Estrone is an aromatized C18 steroid with a 3-hydroxyl group and a 17-ketone. Estrone is a major mammalian estrogen. It is converted from androstenedione directly, or from testosterone via estradiol. It is produced primarily in the ovaries, placenta, and in peripheral tissues (especially adipose tissue) through conversion of adrostenedione.

Ethinylestradiol is chemically and biologically identical to endogenous human oestradiol. It substitutes for the loss of estrogen production in menopausal women, and alleviates menopausal symptoms. Estrogens prevent bone loss following menopause or ovariectomy.