Brain and ovary, uterine endometrium, cervical mucus, targets of hormonal contraceptives. The hypothalamus regulates the secretion of FSH and LH from the pituitary gland. FSH and LH occur at the time of follicular phase and ovulation. In case of fertilization, the egg fertilized by the spermatozoa migrates to the uterus for its nesting in the endometrium. Hormonal contraception acts by blocking the hypothalamic-pituitary axis, blocking ovulation, rendering the endometrium unsuitable for nesting and / or modifying cervical mucus, making it unfit for sperm migration.