Hormones are commonly referred to as "hormones", a general term for the hormones secreted by the human endocrine system that regulate physiological balance. The chemical composition of hormones is roughly divided into five categories: proteins, peptides, glycoproteins, steroids and amino acids. Female hormones, also called estrogens, are one of the king sex hormones in the female body, including estrone, estradiol and estriol. It is secreted by the follicular endothelial cells of the ovarian cortex and the corpus luteum. In addition, the placenta and adrenal cortex can also secrete varying amounts of estrogen.

Female hormones play the following roles: promote the development of female reproductive organs and maintain their normal state; promote the emergence of female secondary sexual characteristics, namely, pubic and axillary hair growth, breasts, subcutaneous fat plumping; maintenance of the female sexual function; in the menstrual cycle to make the uterine glands and blood vessel hyperplasia, thickening of the lining of the uterine gland and proliferative phase changes.

Prompting the vaginal epithelium proliferation, keratinization and glycogen content increases, so that the vagina to maintain an acidic environment to improve the vaginal resistance, is conducive to preventing the growth of bacteria; can enhance the sensitivity of the uterus and fallopian tube muscles, pregnancy and childbirth have a certain significance; can make the uterine cervix softer, cervical mucus secretion increased, thinning, and conducive to the passage of sperm. In addition, estrogen has a mild effect on the fusion of bone pathways, and also has an effect on metabolism, especially in accelerating protein synthesis. During pregnancy, estrogen also contributes to fetal growth.

In men, the supporting cells of the testes also produce varying amounts of estrogen. Synthetic estrogens are derived from steroidal estrogens. The commonly used ones in the clinic are hexestrol and ethinyl estradiol, and the injectable ones are estradiol benzoate. It is mainly used for the treatment of adolescent functional uterine bleeding, menopausal syndrome, senile vaginitis and amenorrhea.