Birth Control Shots:
Birth Control Shots are a long-acting form of progesterone, a hormone that is naturally manufactured in a girl's ovaries. The shot is given as an injection in the upper arm or in the buttocks once every 3 months to protect a women from becoming pregnant. The hormone progesterone in the birth control shot primarily works by preventing ovulation (the release of an egg during the monthly cycle). If a women doesn't ovulate, she cannot get pregnant because there is no egg to be fertilized.