Types

A contraceptive pill can contain two different types of hormones. The combination pill, which most women take, includes the hormones estrogen and progestin. There is also another pill called the mini pill, which is made of only progestin.

Effects

When the pill is taken, the hormones work so that the ovaries do not release an egg; if there is no egg, no fertilization can occur. The hormones also increase the thickness of the cervical mucus, blocking sperm and preventing a fertilized egg.

Additional Effect

The hormones that the pill contains can also thin the lining of the uterus, which can ultimately prevent pregnancy because a fertilized egg would not be able to attach firmly to the uterine wall.

Effectiveness

Ultimately, the contraceptive pill is so effective because of the way the hormones it contains interacts with the body. When the contraceptive pill is used and taken as is suggested, the percentage possibility of pregnancy significantly decreases. Studies found that of 100 women taking the pill daily, only one will become pregnant.

Warning

The contraceptive pill must be taken each day. If a day is missed, a woman is advised to take two pills the following day. Chances of pregnancy increase if the pill is not taken at the same time on a daily basis. If it is missed more than two consecutive days, a health-care provider should be contacted for advice and suggestions.

Source:

Planned Parenthood: Birth Control Pill