Contraception is the use of artificial or natural means to prevent conception, or pregnancy.
Oral Contraceptives (Birth Control Pills) at present, more than 20 brand names and more than twice that number of formulations of oral contraceptives are available. Because they are 98 to 99 percent effective, oral contraceptives offer women the most reliable form of easily reversible contraception (other than abstinence) from sexual intercourse.
Birth control pills use synthetic hormones similar to the ones made in the ovaries. There are two types of pills currently manufactured in the United States: a combination pill, with both synthetic progesterone (progestin) and synthetic estrogen; and mini-pills, which contain only progestin.