ESTROGEN

 While estrogens are present in both men and women, they are usually present at significantly higher levels in women of reproductive age.
They promote the development of female secondary sex characteristics, such as breasts, and are also involved in the thickening of the endometrium and other aspects of regulating the menstrual cycle.
Like all steroid hormones, estrogens readily diffuse across the cell membrane; inside the cell, they interact with estrogen receptors.
The three major naturally occurring estrogens in women are estradiol, estriol and estrone.
Estrogens are used as part of some oral contraceptives and also in estrogen replacement therapy of post-menopausal women.

Hormone replacement therapy

Hormone replacement therapy (HRT) is a system of medical treatment for perimenopausal and postmenopausal women, based on the assumption that it may prevent discomfort and health problems caused by diminished circulating estrogen hormones.

The treatment involves a series of drugs designed to artificially boost hormone levels.
The main types of hormones involved are estrogens, progesterone or progestins, and sometimes testosterone

Progesterone
— Progesterone is a C-21 steroid hormone involved in the female menstrual cycle, pregnancy (supports gestation) and embryogenesis of humans and other