Hormonal contraception or hormonal birth control refers to any medication or medical preparation that contains either estrogen or progesterone or a combination of the two hormones that a woman takes in order to prevent a pregnancy from occurring. Hormonal birth control is often prescribed to treat other medical conditions, as well, such as acne, heavy periods, and relief for the symptoms of PCOS, endometriosis, etc. Hormonal contraception may be taken orally, implanted, injected, absorbed via a patch on the skin’s surface, or placed inside the vagina. Hormonal contraception acts by either preventing the ovulation of a matured egg from the ovary each month, by making the cervix more difficult for the sperm to pass through, or by making the lining of the uterus less capable of supporting the implantation of an embryo.