The pill is a hormonal contraceptive that is claimed to be up to 99.9% effective. It is ingested orally, and it prevents the ovary from releasing an egg. The pill also works in other ways to prevent pregnancy, such as changing the cervical mucus to prevent sperm from from finding an egg. Most of the time the pill comes in a pack with 21 pills, and the pills are taken each day at the same time for 21days, and then stops when the woman has her period. The pill comes with several side effects like irregular menstrual cycle bleeding, mood swings, blood clots (more common among women who smoke), nausea, and dizziness. The pill is very effective against pregnancy. However, the pill is not 100% effective, and I hear ALL THE TIME about women who still get pregnant despite being on the pill. The pill also does not protect against sexually transmitted diseases.